Science.gov

Sample records for cumulative lead exposure

  1. Association of Cumulative Lead Exposure with Parkinson’s Disease

    PubMed Central

    Weisskopf, Marc G.; Weuve, Jennifer; Nie, Huiling; Saint-Hilaire, Marie-Helene; Sudarsky, Lewis; Simon, David K.; Hersh, Bonnie; Schwartz, Joel; Wright, Robert O.; Hu, Howard

    2010-01-01

    Background Research using reconstructed exposure histories has suggested an association between heavy metal exposures, including lead, and Parkinson’s disease (PD), but the only study that used bone lead, a biomarker of cumulative lead exposure, found a nonsignificant increase in risk of PD with increasing bone lead. Objectives We sought to assess the association between bone lead and PD. Methods Bone lead concentrations were measured using 109Cd excited K-shell X-ray fluorescence from 330 PD patients (216 men, 114 women) and 308 controls (172 men, 136 women) recruited from four clinics for movement disorders and general-community cohorts. Adjusted odds ratios (ORs) for PD were calculated using logistic regression. Results The average age of cases and controls at bone lead measurement was 67 (SD = 10) and 69 (SD = 9) years of age, respectively. In primary analyses of cases and controls recruited from the same groups, compared with the lowest quartile of tibia lead, the OR for PD in the highest quartile was 3.21 [95% confidence interval (CI), 1.17–8.83]. Results were similar but slightly weaker in analyses restricted to cases and controls recruited from the movement disorders clinics only (fourth-quartile OR = 2.57; 95% CI, 1.11–5.93) or when we included controls recruited from sites that did not also contribute cases (fourth-quartile OR = 1.91; 95% CI, 1.01–3.60). We found no association with patella bone lead. Conclusions These findings, using an objective biological marker of cumulative lead exposure among typical PD patients seen in our movement disorders clinics, strengthen the evidence that cumulative exposure to lead increases the risk of PD. PMID:20807691

  2. Association of cumulative lead exposure with Parkinson's disease.

    PubMed

    Weisskopf, Marc G; Weuve, Jennifer; Nie, Huiling; Saint-Hilaire, Marie-Helene; Sudarsky, Lewis; Simon, David K; Hersh, Bonnie; Schwartz, Joel; Wright, Robert O; Hu, Howard

    2010-11-01

    Research using reconstructed exposure histories has suggested an association between heavy metal exposures, including lead, and Parkinson's disease (PD), but the only study that used bone lead, a biomarker of cumulative lead exposure, found a nonsignificant increase in risk of PD with increasing bone lead. We sought to assess the association between bone lead and PD. Bone lead concentrations were measured using 109Cd excited K-shell X-ray fluorescence from 330 PD patients (216 men, 114 women) and 308 controls (172 men, 136 women) recruited from four clinics for movement disorders and general-community cohorts. Adjusted odds ratios (ORs) for PD were calculated using logistic regression. The average age of cases and controls at bone lead measurement was 67 (SD = 10) and 69 (SD = 9) years of age, respectively. In primary analyses of cases and controls recruited from the same groups, compared with the lowest quartile of tibia lead, the OR for PD in the highest quartile was 3.21 [95% confidence interval (CI), 1.17-8.83]. Results were similar but slightly weaker in analyses restricted to cases and controls recruited from the movement disorders clinics only (fourth-quartile OR = 2.57; 95% CI, 1.11-5.93) or when we included controls recruited from sites that did not also contribute cases (fourth-quartile OR = 1.91; 95% CI, 1.01-3.60). We found no association with patella bone lead. These findings, using an objective biological marker of cumulative lead exposure among typical PD patients seen in our movement disorders clinics, strengthen the evidence that cumulative exposure to lead increases the risk of PD.

  3. Cumulative Lead Exposure and Age-related Hearing Loss: The VA Normative Aging Study

    PubMed Central

    Park, Sung Kyun; Elmarsafawy, Sahar; Mukherjee, Bhramar; Spiro, Avron; Vokonas, Pantel S.; Nie, Huiling; Weisskopf, Marc G.; Schwartz, Joel; Hu, Howard

    2010-01-01

    Although lead has been associated with hearing loss in occupational settings and in children, little epidemiologic research has been conducted on the impact of cumulative lead exposure on age-related hearing loss in the general population. We determined whether bone lead levels, a marker of cumulative lead exposure, are associated with decreased hearing ability in 448 men from the Normative Aging Study, seen between 1962 and 1996 (2,264 total observations). Air conduction hearing thresholds were measured at 0.25 to 8 kHz and pure tone averages (PTA) (mean of 0.5, 1, 2 and 4 kHz) were computed. Tibia and patella lead levels were measured using K x-ray fluorescence between 1991 and 1996. In cross-sectional analyses, after adjusting for potential confounders including occupational noise, patella lead levels were significantly associated with poorer hearing thresholds at 2, 3, 4, 6 and 8 kHz and PTA. The odds of hearing loss significantly increased with patella lead levels. We also found significant positive associations between tibia lead and the rate change in hearing thresholds at 1, 2, and 8 kHz and PTA in longitudinal analyses. Our results suggest that chronic low-level lead exposure may be an important risk factor for age-related hearing loss and reduction of lead exposure could help prevent or delay development of age-related hearing loss. PMID:20638461

  4. Brainstem auditory evoked potentials in children with low level cumulative lead exposure

    PubMed Central

    Alvarenga, Kátia F.; Morata, Thais C.; Lopes, Andréa Cintra; Feniman, Mariza Ribeiro; Corteletti, Lilian Cássia Bórnia Jacob

    2015-01-01

    Introduction Earlier studies have demonstrated an auditory effect of lead exposure in children,but information on the effects of low chronic exposures needs to be further elucidated. Objective To investigate the effect of low chronic exposures of the auditory system in childrenwith a history of low blood lead levels, using an auditory electrophysiological test. Methods Contemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6years, 8 months ± 3 years, 2 months). Results The mean time-integrated cumulative blood lead index was 12 g/dL (SD ± 5.7, range:2.433). All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I---III, III---V, and I---V, and the cumulative lead values. Conclusion No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area. PMID:25458254

  5. Cumulative Lead Exposure and Tooth Loss in Men: The Normative Aging Study

    PubMed Central

    Arora, Manish; Weuve, Jennifer; Weisskopf, Marc G.; Sparrow, David; Nie, Huiling; Garcia, Raul I.; Hu, Howard

    2009-01-01

    Background Individuals previously exposed to lead remain at risk because of endogenous release of lead stored in their skeletal compartments. However, it is not known if long-term cumulative lead exposure is a risk factor for tooth loss. Objectives We examined the association of bone lead concentrations with loss of natural teeth. Methods We examined 333 men enrolled in the Veterans Affairs Normative Aging Study. We used a validated K-shell X-ray fluorescence (KXRF) method to measure lead concentrations in the tibial midshaft and patella. A dentist recorded the number of teeth remaining, and tooth loss was categorized as 0, 1–8 or ≥ 9 missing teeth. We used proportional odds models to estimate the association of bone lead biomarkers with tooth loss, adjusting for age, smoking, diabetes, and other putative confounders. Results Participants with ≥ 9 missing teeth had significantly higher bone lead concentrations than those who had not experienced tooth loss. In multivariable-adjusted analyses, men in the highest tertile of tibia lead (> 23 μg/g) and patella lead (> 36 μg/g) had approximately three times the odds of having experienced an elevated degree of tooth loss (≥ 9 vs. 0–8 missing teeth or ≥ 1 vs. 0 missing teeth) as those in the lowest tertile [prevalence odds ratio (OR) = 3.03; 95% confidence interval (CI), 1.60–5.76 and OR = 2.41; 95% CI, 1.30–4.49, respectively]. Associations between bone lead biomarkers and tooth loss were similar in magnitude to the increased odds observed in participants who were current smokers. Conclusion Long-term cumulative lead exposure is associated with increased odds of tooth loss. PMID:20019902

  6. Lead-Related Genetic Loci, Cumulative Lead Exposure and Incident Coronary Heart Disease: The Normative Aging Study

    PubMed Central

    Weisskopf, Marc G.; Sparrow, David; Schwartz, Joel; Hu, Howard; Park, Sung Kyun

    2016-01-01

    Background Cumulative exposure to lead is associated with cardiovascular outcomes. Polymorphisms in the δ-aminolevulinic acid dehydratase (ALAD), hemochromatosis (HFE), heme oxygenase-1 (HMOX1), vitamin D receptor (VDR), glutathione S-transferase (GST) supergene family (GSTP1, GSTT1, GSTM1), apolipoprotein E (APOE),angiotensin II receptor-1 (AGTR1) and angiotensinogen (AGT) genes, are believed to alter toxicokinetics and/or toxicodynamics of lead. Objectives We assessed possible effect modification by genetic polymorphisms in ALAD, HFE, HMOX1, VDR, GSTP1, GSTT1, GSTM1, APOE, AGTR1 and AGT individually and as the genetic risk score (GRS) on the association between cumulative lead exposure and incident coronary heart disease (CHD) events. Methods We used K-shell-X-ray fluorescence to measure bone lead levels. GRS was calculated on the basis of 22 lead-related loci. We constructed Cox proportional hazard models to compute adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for incident CHD. We applied inverse probability weighting to account for potential selection bias due to recruitment into the bone lead sub-study. Results Significant effect modification was found by VDR, HMOX1, GSTP1, APOE, and AGT genetic polymorphisms when evaluated individually. Further, the bone lead-CHD associations became larger as GRS increases. After adjusting for potential confounders, a HR of CHD was 2.27 (95%CI: 1.50–3.42) with 2-fold increase in patella lead levels, among participants in the top tertile of GRS. We also detected an increasing trend in HRs across tertiles of GRS (p-trend = 0.0063). Conclusions Our findings suggest that lead-related loci as a whole may play an important role in susceptibility to lead-related CHD risk. These findings need to be validated in a separate cohort containing bone lead, lead-related genetic loci and incident CHD data. PMID:27584680

  7. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    SciTech Connect

    Guilmette, R.A.; Laurer, G.R.; Lambert, W.E.; Gilliland, F.D.

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  8. Dose-Response Relationship between Cumulative Occupational Lead Exposure and the Associated Health Damages: A 20-Year Cohort Study of a Smelter in China

    PubMed Central

    Wu, Yue; Gu, Jun-Ming; Huang, Yun; Duan, Yan-Ying; Huang, Rui-Xue; Hu, Jian-An

    2016-01-01

    Long-term airborne lead exposure, even below official occupational limits, has been found to cause lead poisoning at higher frequencies than expected, which suggests that China’s existing occupational exposure limits should be reexamined. A retrospective cohort study was conducted on 1832 smelting workers from 1988 to 2008 in China. These were individuals who entered the plant and came into continuous contact with lead at work for longer than 3 months. The dose-response relationship between occupational cumulative lead exposure and lead poisoning, abnormal blood lead, urinary lead and erythrocyte zinc protoporphyrin (ZPP) were analyzed and the benchmark dose lower bound confidence limits (BMDLs) were calculated. Statistically significant positive correlations were found between cumulative lead dust and lead fumes exposures and workplace seniority, blood lead, urinary lead and ZPP values. A dose-response relationship was observed between cumulative lead dust or lead fumes exposure and lead poisoning (p < 0.01). The BMDLs of the cumulative occupational lead dust and fumes doses were 0.68 mg-year/m3 and 0.30 mg-year/m3 for lead poisoning, respectively. The BMDLs of workplace airborne lead concentrations associated with lead poisoning were 0.02 mg/m3 and 0.01 mg/m3 for occupational exposure lead dust and lead fume, respectively. In conclusion, BMDLs for airborne lead were lower than occupational exposure limits, suggesting that the occupational lead exposure limits need re-examination and adjustment. Occupational cumulative exposure limits (OCELs) should be established to better prevent occupational lead poisoning. PMID:26999177

  9. Dose-Response Relationship between Cumulative Occupational Lead Exposure and the Associated Health Damages: A 20-Year Cohort Study of a Smelter in China.

    PubMed

    Wu, Yue; Gu, Jun-Ming; Huang, Yun; Duan, Yan-Ying; Huang, Rui-Xue; Hu, Jian-An

    2016-03-16

    Long-term airborne lead exposure, even below official occupational limits, has been found to cause lead poisoning at higher frequencies than expected, which suggests that China's existing occupational exposure limits should be reexamined. A retrospective cohort study was conducted on 1832 smelting workers from 1988 to 2008 in China. These were individuals who entered the plant and came into continuous contact with lead at work for longer than 3 months. The dose-response relationship between occupational cumulative lead exposure and lead poisoning, abnormal blood lead, urinary lead and erythrocyte zinc protoporphyrin (ZPP) were analyzed and the benchmark dose lower bound confidence limits (BMDLs) were calculated. Statistically significant positive correlations were found between cumulative lead dust and lead fumes exposures and workplace seniority, blood lead, urinary lead and ZPP values. A dose-response relationship was observed between cumulative lead dust or lead fumes exposure and lead poisoning (p < 0.01). The BMDLs of the cumulative occupational lead dust and fumes doses were 0.68 mg-year/m³ and 0.30 mg-year/m³ for lead poisoning, respectively. The BMDLs of workplace airborne lead concentrations associated with lead poisoning were 0.02 mg/m³ and 0.01 mg/m³ for occupational exposure lead dust and lead fume, respectively. In conclusion, BMDLs for airborne lead were lower than occupational exposure limits, suggesting that the occupational lead exposure limits need re-examination and adjustment. Occupational cumulative exposure limits (OCELs) should be established to better prevent occupational lead poisoning.

  10. Cumulative lead exposure is associated with reduced olfactory recognition performance in elderly men: the Normative Aging Study

    PubMed Central

    Grashow, Rachel; Sparrow, David; Hu, Howard; Weisskopf, Marc G.

    2015-01-01

    Introduction Olfactory dysfunction has been identified as an early warning sign for Alzheimer’s disease, Parkinson’s disease, dementia and more. A few occupational and environmental exposures have also been associated with reduced olfactory function, although the effects of long term environmental exposure to lead on olfactory dysfunction have not been explored. Here we performed olfactory recognition testing in elderly men in a community-dwelling cohort and examined the association with cumulative lead exposure, as assessed by lead in tibial and patellar bone. Methods Olfactory recognition was measured in 165 men from the Normative Aging Study (NAS) who had previously taken part in bone lead measurements using K-X-Ray fluorescence (KXRF). Olfactory recognition was measured using the University of Pennsylvania Smell Identification Test (UPSIT). Associations between olfactory recognition, global cognition and cumulative lead exposure were estimated using linear regression, with additional adjustment for age, smoking, and functional polymorphism status for hemochromatosis (HFE), transferrin (TfC2), glutathione-s-transferase Pi1 (GSTP1) and apolipoprotein E (APOE) genotypes. Sensitivity analyses explored olfactory recognition in men with high global cognitive function as measured using the Mini-Mental Status Exam (MMSE). Results The average age of the NAS participants at the time of olfactory recognition testing was 80.3 (standard deviation or SD = 5.7) years. Mean tibia lead was 16.3 (SD = 12.0) μg/g bone, mean patella lead was 22.4 (SD = 14.4) μg/g bone, and mean UPSIT score was 26.9 out of 40 (SD = 7.0). Consistent with previous findings, age at olfaction testing was negatively associated with UPSIT score. Tibia (but not patella) bone lead was negatively associated with olfaction recognition (per 15 μg/g tibia lead: β = −1.57; 95% CI: −2.93, −0.22; p = 0.02) in models adjusted for smoking and age. Additional adjustment for education did not

  11. Determining Prenatal, Early Childhood and Cumulative Long-Term Lead Exposure Using Micro-Spatial Deciduous Dentine Levels

    PubMed Central

    Arora, Manish; Austin, Christine; Sarrafpour, Babak; Hernández-Ávila, Mauricio; Hu, Howard; Wright, Robert O.; Tellez-Rojo, Martha Maria

    2014-01-01

    The aim of this study was to assess the validity of micro-spatial dentine lead (Pb) levels as a biomarker for accurately estimating exposure timing over the prenatal and early childhood periods and long-term cumulative exposure to Pb. In a prospective pregnancy cohort sub-sample of 85 subjects, we compared dentine Pb levels measured using laser ablation-inductively coupled plasma mass spectrometry with Pb concentrations in maternal blood collected in the second and third trimesters, maternal bone, umbilical cord blood, and childhood serial blood samples collected from the ages of 3 months to ≥6 years. We found that Pb levels (as 208Pb:43Ca) in dentine formed at birth were significantly associated with cord blood Pb (Spearman ρ = 0.69; n = 27; p<0.0001). The association of prenatal dentine Pb with maternal patella Pb (Spearman ρ = 0.48; n = 59; p<0.0001) was stronger than that observed for tibia Pb levels (Spearman ρ = 0.35; n = 41; p<0.03). When assessing postnatal exposure, we found that Pb levels in dentine formed at 3 months were significantly associated with Pb concentrations in children’s blood collected concurrently (Spearman ρ = 0.64; n = 55; p<0.0001). We also found that mean Pb concentrations in secondary dentine (that is formed from root completion to tooth shedding) correlated positively with cumulative blood lead index (Spearman ρ = 0.38; n = 75; p<0.0007). Overall, our results support that micro-spatial measurements of Pb in dentine can be reliably used to reconstruct Pb exposure timing over the prenatal and early childhood periods, and secondary dentine holds the potential to estimate long-term exposure up to the time the tooth is shed. PMID:24841926

  12. Relation of cumulative low-level lead exposure to depressive and phobic anxiety symptom scores in middle-age and elderly women.

    PubMed

    Eum, Ki-Do; Korrick, Susan A; Weuve, Jennifer; Okereke, Olivia; Kubzansky, Laura D; Hu, Howard; Weisskopf, Marc G

    2012-06-01

    Different lines of evidence suggest that low-level lead exposure could be a modifiable risk factor for adverse psychological symptoms, but little work has explored this relation. We assessed whether bone lead--a biomarker of cumulative lead exposure--is associated with depression and anxiety symptoms among middle-age and elderly women. Participants were 617 Nurses' Health Study participants with K-shell X-ray fluorescence bone lead measures and who had completed at last one Mental Health Index 5-item scale (MHI-5) and the phobic anxiety scale of the Crown-Crisp Index (CCI) assessment at mean ± SD age of 59 ± 9 years (range, 41-83 years). With exposure expressed as tertiles of bone lead, we analyzed MHI-5 scores as a continuous variable using linear regression and estimated the odds ratio (OR) of a CCI score ≥ 4 using generalized estimating equations. There were no significant associations between lead and either outcome in the full sample, but associations were found among premenopausal women and women who consistently took hormone replacement therapy (HRT) between menopause and bone lead measurement (n = 142). Compared with women in the lowest tertile of tibia lead, those in the highest scored 7.78 points worse [95% confidence interval (CI): -11.73, -3.83] on the MHI-5 (p-trend = 0.0001). The corresponding OR for CCI ≥ 4 was 2.79 (95% CI: 1.02, 7.59; p-trend = 0.05). No consistent associations were found with patella lead. These results provide support for an association of low-level cumulative lead exposure with increased depressive and phobic anxiety symptoms among older women who are premenopausal or who consistently take postmenopausal HRT.

  13. Relation of Cumulative Low-Level Lead Exposure to Depressive and Phobic Anxiety Symptom Scores in Middle-Age and Elderly Women

    PubMed Central

    Eum, Ki-Do; Korrick, Susan A.; Weuve, Jennifer; Okereke, Olivia; Kubzansky, Laura D.; Hu, Howard

    2012-01-01

    Background: Different lines of evidence suggest that low-level lead exposure could be a modifiable risk factor for adverse psychological symptoms, but little work has explored this relation. Objective: We assessed whether bone lead—a biomarker of cumulative lead exposure—is associated with depression and anxiety symptoms among middle-age and elderly women. Methods: Participants were 617 Nurses’ Health Study participants with K-shell X-ray fluorescence bone lead measures and who had completed at last one Mental Health Index 5-item scale (MHI-5) and the phobic anxiety scale of the Crown-Crisp Index (CCI) assessment at mean ± SD age of 59 ± 9 years (range, 41–83 years). With exposure expressed as tertiles of bone lead, we analyzed MHI-5 scores as a continuous variable using linear regression and estimated the odds ratio (OR) of a CCI score ≥ 4 using generalized estimating equations. Results: There were no significant associations between lead and either outcome in the full sample, but associations were found among premenopausal women and women who consistently took hormone replacement therapy (HRT) between menopause and bone lead measurement (n = 142). Compared with women in the lowest tertile of tibia lead, those in the highest scored 7.78 points worse [95% confidence interval (CI): –11.73, –3.83] on the MHI-5 (p-trend = 0.0001). The corresponding OR for CCI ≥ 4 was 2.79 (95% CI: 1.02, 7.59; p-trend = 0.05). No consistent associations were found with patella lead. Conclusions: These results provide support for an association of low-level cumulative lead exposure with increased depressive and phobic anxiety symptoms among older women who are premenopausal or who consistently take postmenopausal HRT. PMID:22538241

  14. Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

    SciTech Connect

    Bellis, David J.; Hetter, Katherine M.; Jones, Joseph; Amarasiriwardena, Dula; Parsons, Patrick J.

    2008-01-15

    Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 {mu}g g{sup -1}. Linear regression of whole tooth lead ({mu}g g{sup -1}) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r{sup 2}=0.647 (p<0.0001). Laser ablation inductively coupled plasma mass spectrometry was employed to determine lead content at micrometer scale spatial resolution in the teeth of seven goats representing the dosing range. Highly localized concentrations of lead, ranging from about 10 to 2000 {mu}g g{sup -1}, were found in circumpulpal dentine. Linear regression of circumpulpal lead ({mu}g g{sup -1}) on cumulative lead dose (g) yielded a slope of 23 with r{sup 2}=0.961 (p=0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats.

  15. Lead in teeth from lead-dosed goats: Microdistribution and relationship to the cumulative lead dose

    PubMed Central

    Bellis, David J.; Hetter, Katherine M.; Jones, Joseph; Amarasiriwardena, Dula; Parsons, Patrick J.

    2013-01-01

    Teeth are commonly used as a biomarker of long-term lead exposure. There appear to be few data, however, on the content or distribution of lead in teeth where data on specific lead intake (dose) are also available. This study describes the analysis of a convenience sample of teeth from animals that were dosed with lead for other purposes, i.e., a proficiency testing program for blood lead. Lead concentration of whole teeth obtained from 23 animals, as determined by atomic absorption spectrometry, varied from 0.6 to 80 μg g−1. Linear regression of whole tooth lead (μg g−1) on the cumulative lead dose received by the animal (g) yielded a slope of 1.2, with r2 = 0.647 (p<0.0001). Laser ablation inductively coupled plasma mass spectrometry was employed to determine lead content at micrometer scale spatial resolution in the teeth of seven goats representing the dosing range. Highly localized concentrations of lead, ranging from about 10 to 2000 μg g−1, were found in circumpulpal dentine. Linear regression of circumpulpal lead (μg g−1) on cumulative lead dose (g) yielded a slope of 23 with r2 = 0.961 (p = 0.0001). The data indicated that whole tooth lead, and especially circumpulpal lead, of dosed goats increased linearly with cumulative lead exposure. These data suggest that circumpulpal dentine is a better biomarker of cumulative lead exposure than is whole tooth lead, at least for lead-dosed goats. PMID:17644083

  16. Lagging Exposure Information in Cumulative Exposure-Response Analyses

    PubMed Central

    Richardson, David B.; Cole, Stephen R.; Chu, Haitao; Langholz, Bryan

    2011-01-01

    Lagging exposure information is often undertaken to allow for a latency period in cumulative exposure-disease analyses. The authors first consider bias and confidence interval coverage when using the standard approaches of fitting models under several lag assumptions and selecting the lag that maximizes either the effect estimate or model goodness of fit. Next, they consider bias that occurs when the assumption that the latency period is a fixed constant does not hold. Expressions were derived for bias due to misspecification of lag assumptions, and simulations were conducted. Finally, the authors describe a method for joint estimation of parameters describing an exposure-response association and the latency distribution. Analyses of associations between cumulative asbestos exposure and lung cancer mortality among textile workers illustrate this approach. Selecting the lag that maximizes the effect estimate may lead to bias away from the null; selecting the lag that maximizes model goodness of fit may lead to confidence intervals that are too narrow. These problems tend to increase as the within-person exposure variation diminishes. Lagging exposure assignment by a constant will lead to bias toward the null if the distribution of latency periods is not a fixed constant. Direct estimation of latency periods can minimize bias and improve confidence interval coverage. PMID:22047823

  17. Use of a Cumulative Exposure Index to Estimate the Impact of Tap Water Lead Concentration on Blood Lead Levels in 1- to 5-Year-Old Children (Montréal, Canada)

    PubMed Central

    Ngueta, Gerard; Abdous, Belkacem; Tardif, Robert; St-Laurent, Julie; Levallois, Patrick

    2015-01-01

    Background Drinking water is recognized as a source of lead (Pb) exposure. However, questions remain about the impact of chronic exposure to lead-contaminated water on internal dose. Objective Our goal was to estimate the relation between a cumulative water Pb exposure index (CWLEI) and blood Pb levels (BPb) in children 1–5 years of ages. Methods Between 10 September 2009 and 27 March 2010, individual characteristics and water consumption data were obtained from 298 children. Venous blood samples were collected (one per child) and a total of five 1-L samples of water per home were drawn from the kitchen tap. A second round of water collection was performed between 22 June 2011 and 6 September 2011 on a subsample of houses. Pb analyses used inductively coupled plasma mass spectroscopy. Multiple linear regressions were used to estimate the association between CWLEI and BPb. Results Each 1-unit increase in CWLEI multiplies the expected value of BPb by 1.10 (95% CI: 1.06, 1.15) after adjustment for confounders. Mean BPb was significantly higher in children in the upper third and fourth quartiles of CWLEI (0.7–1.9 and ≥ 1.9 μg/kg of body weight) compared with the first (< 0.2 μg/kg) after adjusting for confounders (19%; 95% CI: 0, 42% and 39%; 95% CI: 15, 67%, respectively). The trends analysis yielded a p-value < 0.0001 after adjusting for confounders suggesting a dose–response relationship between percentiles of CWLEI and BPb. Conclusions In children 1–5 years of age, BPb was significantly associated with water lead concentration with an increase starting at a cumulative lead exposure of ≥ 0.7 μg Pb/kg of body weight. In this age group, an increase of 1 μg/L in water lead would result in an increase of 35% of BPb after 150 days of exposure. Citation Ngueta G, Abdous B, Tardif R, St-Laurent J, Levallois P. 2016. Use of a cumulative exposure index to estimate the impact of tap water lead concentration on blood lead levels in 1- to 5-year-old children

  18. Cumulative blood lead levels and neurobehavioral test performance.

    PubMed

    Chia, S E; Chia, H P; Ong, C N; Jeyaratnam, J

    1997-01-01

    The current scientific literature provides inadequate evidence to conclude whether or not cumulative exposure to or absorption of lead adversely affects performance in neurobehavioral tests in adults. One of reasons for this controversy is the lack of studies with good cumulative exposure to or dose of lead. The aims of this study are to compare the neurobehavioral test performances of a group of lead-exposed workers and a referent group, and to study the association of the neurobehavioral test performances with concurrent blood lead levels and cumulative blood lead levels. Fifty lead battery workers and 97 non-exposed (referent) workers from a vehicle maintenance workshop were evaluated on their neurobehavioral performance using the World Health Organization Neurobehavioral Core Test Battery (WHO-NCTB). The geometric mean concurrent blood lead (ConPb) of the exposed and referent groups were 37.1 (range 13.2-64.6) microg/100 ml and 6.1 (range 2.4-12.4) microg/100 ml, respectively. Cumulative blood lead (CumPb) was defined as area under the curve for the number of years each worker was exposed to lead (three workers previous blood lead results were not available). ConPb and CumPb were used to study the association with the neurobehavioral test results. The exposed group had significantly poorer manual dexterity, perceptual-motor speed, and motor steadiness compared with the referents. The standardized partial regression coefficients were higher for CumPb than ConPb for most of the neurobehavioral test results. In the group >35 years old, there were significantly stronger associations between CumPb and Digit Symbol and Trail Making Part A results than for ConPb which are tests of perceptual and motor skills. CumPb was a better predictor than ConPb of the effects of lead on neurobehavioral performances.

  19. Cumulative Chemical Exposures During Pregnancy and Early Development

    PubMed Central

    Mitro, Susanna D.; Johnson, Tyiesha; Zota, Ami R.

    2015-01-01

    Industrial and consumer product chemicals are widely used, leading to ubiquitous human exposure to the most common classes. Because these chemicals may affect developmental milestones, exposures in pregnant women and developing fetuses are of particular interest. In this review, we discuss the prevalence of chemical exposures in pregnant women, the chemical class-specific relationships between maternal and fetal exposures, and the major sources of exposures for six chemical classes of concern: phthalates, phenols, perfluorinated compounds (PFCs), flame retardants, polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCs). Additionally, we describe the current efforts to characterize cumulative exposures to synthetic chemicals during pregnancy. We conclude by highlighting gaps in the literature and discussing possible applications of the findings to reduce the prevalence of cumulative exposures during pregnancy. PMID:26341623

  20. Blood lead levels and cumulative blood lead index (CBLI) as predictors of late neurodevelopment in lead poisoned children

    PubMed Central

    Nie, Linda H.; Wright, Robert O.; Bellinger, David C.; Hussain, Javed; Amarasiriwardena, Chitra; Chettle, David R.; Pejović-Milić, Ana; woolf, Alan; Shannon, Michael

    2011-01-01

    Objective To find the best lead exposure assessment marker for children. Methods We recruited 11 children, calculated a cumulative blood lead index (CBLI) for the children, measured their concurrent BLL, assessed their development, and measured their bone lead level. Results Nine of 11 children had clinically significant neurodevelopment problems. CBLI and current blood lead level, but not the peak lead level, were significantly or marginally negatively associated with the full-scale IQ score. Conclusion Lead exposure at younger age significantly impacts a child’s later neurodevelopment. CBLI may be a better predictor of neurodevelopment than are current or peak blood lead levels. PMID:21827276

  1. Psychiatric epidemiologic study of occupational lead exposure

    SciTech Connect

    Parkinson, D.K.; Ryan, C.; Bromet, E.J.; Connell, M.M.

    1986-02-01

    The association of occupational lead exposure with neuropsychiatric functioning was evaluated using data collected in 1982 in eastern Pennsylvania from 288 lead-exposed workers and 181 nonexposed subjects. Both current and cumulative exposure indices were used. After controlling for age, education, and income, few meaningful differences between exposed and control workers were found on either neuropsychologic or psychosocial variables. Dose-response analyses indicated that among lead-exposed workers, cumulative and current exposure were unrelated to neuropsychologic performance. The only meaningful associations occurred between exposure and level of conflict in interpersonal relationships. The results thus give evidence against hypotheses suggesting adverse neuropsychologic effects.

  2. Cumulative Estrogen Exposure and Prospective Memory in Older Women

    ERIC Educational Resources Information Center

    Hesson, Jacqueline

    2012-01-01

    This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to…

  3. Cumulative Estrogen Exposure and Prospective Memory in Older Women

    ERIC Educational Resources Information Center

    Hesson, Jacqueline

    2012-01-01

    This study looked at cumulative lifetime estrogen exposure, as estimated with a mathematical index (Index of Cumulative Estrogen Exposure (ICEE)) that included variables (length of time on estrogen therapy, age at menarche and menopause, postmenopausal body mass index, time since menopause, nulliparity and duration of breastfeeding) known to…

  4. Childhood Cumulative Risk Exposure and Adult Amygdala Volume and Function.

    PubMed

    Evans, Gary W; Swain, James E; King, Anthony P; Wang, Xin; Javanbakht, Arash; Ho, S Shaun; Angstadt, Michael; Phan, K Luan; Xie, Hong; Liberzon, Israel

    2016-06-01

    Considerable work indicates that early cumulative risk exposure is aversive to human development, but very little research has examined the neurological underpinnings of these robust findings. This study investigates amygdala volume and reactivity to facial stimuli among adults (mean 23.7 years of age, n = 54) as a function of cumulative risk exposure during childhood (9 and 13 years of age). In addition, we test to determine whether expected cumulative risk elevations in amygdala volume would mediate functional reactivity of the amygdala during socioemotional processing. Risks included substandard housing quality, noise, crowding, family turmoil, child separation from family, and violence. Total and left hemisphere adult amygdala volumes were positively related to cumulative risk exposure during childhood. The links between childhood cumulative risk exposure and elevated amygdala responses to emotionally neutral facial stimuli in adulthood were mediated by the corresponding amygdala volumes. Cumulative risk exposure in later adolescence (17 years of age), however, was unrelated to subsequent adult amygdala volume or function. Physical and socioemotional risk exposures early in life appear to alter amygdala development, rendering adults more reactive to ambiguous stimuli such as neutral faces. These stress-related differences in childhood amygdala development might contribute to the well-documented psychological distress as a function of early risk exposure. © 2015 Wiley Periodicals, Inc.

  5. Childhood Cumulative Risk Exposure and Adult Amygdala Volume and Function

    PubMed Central

    Evans, Gary W.; Swain, James E.; King, Anthony P.; Wang, Xin; Javanbakht, Arash; Ho, S. Shaun; Angstadt, Michael; Phan, K. Luan; Xie, Hong; Liberzon, Israel

    2015-01-01

    Considerable work indicates that early cumulative risk exposure is aversive to human development, but very little research has examined neurological underpinnings of these robust findings. We investigated amygdala volume and reactivity to facial stimuli among adults (M = 23.7 years, n = 54) as a function of cumulative risk exposure during childhood (ages 9 and 13). In addition, we tested whether expected, cumulative risk elevations in amygdala volume would mediate functional reactivity of the amygdala during socio-emotional processing. Risks included substandard housing quality, noise, crowding, family turmoil, child separation from family, and violence. Total and left hemisphere adult amygdala volumes, respectively were positively related to cumulative risk exposure during childhood. The links between childhood cumulative risk exposure and elevated amygdala responses to emotionally neutral facial stimuli in adulthood were mediated by the respective amygdala volumes. Cumulative risk exposure in later adolescence (17 years), however, was unrelated to subsequent, adult amygdala volume or function. Physical and socioemotional risk exposures early in life appear to alter amygdala development, rendering adults more reactive to ambiguous stimuli such as neutral faces. These stress-related differences in childhood amygdala development might contribute to well-documented psychological distress as a function of early risk exposure. PMID:26469872

  6. Food Exposures to Lead

    PubMed Central

    Kolbye, Albert C.; Mahaffey, Kathryn R.; Fiorino, John A.; Corneliussen, Paul C.; Jelinek, Charles F.

    1974-01-01

    Exposures to lead have emanated from various sources, including food, throughout human history. Occupational and environmental exposures (especially pica) appear to account for much of the identified human disease, however, food-borne exposures deserve further investigation. Lead residues in food can result from: biological uptake from soils into plants consumed by food animals or man, usage of lead arsenate pesticides, inadvertent addition during food processing, and by leaching them improperly glazed pottery used as food storage or dining utensils. Estimates of total dietary exposure should reflect frequency distribution data on lead levels in specific food commodities in relation to the quantities actually ingested by various sample populations to distinguish degrees of risk associated with particular dietary habits. Earlier estimates of average total dietary intake of lead by adults have been reported to range from above 500 μg/day downward with more recent estimates suggesting averages of 200 μg/day or lower. The strengths and weaknesses of these data are discussed along with analytical and sampling considerations. FDA programs related to food surveillance, epidemiology, and toxicological investigation are briefly described. PMID:4406646

  7. Latino Mothers' Cumulative Food Insecurity Exposure and Child Body Composition.

    PubMed

    Hernandez, Daphne C

    2016-01-01

    To document whether an intergenerational transmission of food insecurity is occurring by assessing low-income foreign-born Latino mothers' experiences with food insecurity as none, once (either childhood or adulthood) or twice (during both childhood and adulthood). Also the association between maternal cumulative food insecurity and children's body composition was examined. Maternal self-reported surveys on retrospective measures of food insecurity during childhood, current measures of food insecurity, and demographics were collected from Houston-area community centers (N = 96). Children's body mass index (BMI) and waist circumference (WC) were directly assessed. Covariate-adjusted logistic regression models analyzed the association between cumulative food insecurity experiences and children's body composition. Fifty-eight percent of mothers experienced food insecurity both as a child and as an adult and 31% of the mothers experienced food insecurity either as a child or adult. Maternal cumulative exposure to food insecurity was unrelated to BMI but was negatively related to elevated WC. Although an intergenerational transmission of food insecurity does exist, maternal cumulative exposure to food insecurity does not impact children's body composition negatively in the short term. Studying the long-term effects of cumulative food insecurity exposure can provide information for the development and timing of obesity interventions.

  8. Time To Pregnancy and occupational lead exposure

    PubMed Central

    Joffe, M; Bisanti, L; Apostoli, P; Kiss, P; Dale, A; Roeleveld, N; Lindbohm, M; Sallmen, M; Vanhoorne, M; Bonde, J

    2003-01-01

    Background: Lead exposure is known to be harmful to the male reproductive system, including impairment of fertility. However, it is unclear whether currently existing low levels of exposure have this effect. Aims: To study retrospectively current workers in lead using industries (battery manufacture, smelting, etc), and in non-lead using control industries, in four European countries, with Time To Pregnancy as the outcome variable, as part of the EU funded Asclepios Project. Methods: Exposure assessment was mainly by blood lead values, which were available from the late 1970s, supplemented by imputed values where necessary. Three exposure models were studied: (1) short term (recent) exposure; (2) total duration of work in a lead using industry; and (3) cumulative exposure. A Cox proportional hazards model with discrete ties was used for the statistical analysis, with covariates for both partners. Results: A total of 1104 subjects took part, of whom 638 were occupationally exposed to lead at the relevant time. Blood lead levels were mainly less than 50 µg/dl. No consistent association of Time To Pregnancy with lead exposure was found in any of the exposure models, although reduced fertility was observed in one category each in models (2) and (3). Conclusions: This basically negative result is unlikely to be due to the misclassification of key variables, to insufficient statistical power, or to bias, for example, response bias. If any impairment of male reproductive function exists at the levels of occupational lead exposure now current, it does not appear to reduce biological fertility. PMID:14504363

  9. Time To Pregnancy and occupational lead exposure.

    PubMed

    Joffe, M; Bisanti, L; Apostoli, P; Kiss, P; Dale, A; Roeleveld, N; Lindbohm, M-L; Sallmén, M; Vanhoorne, M; Bonde, J P

    2003-10-01

    Lead exposure is known to be harmful to the male reproductive system, including impairment of fertility. However, it is unclear whether currently existing low levels of exposure have this effect. To study retrospectively current workers in lead using industries (battery manufacture, smelting, etc), and in non-lead using control industries, in four European countries, with Time To Pregnancy as the outcome variable, as part of the EU funded Asclepios Project. Exposure assessment was mainly by blood lead values, which were available from the late 1970s, supplemented by imputed values where necessary. Three exposure models were studied: (1) short term (recent) exposure; (2) total duration of work in a lead using industry; and (3) cumulative exposure. A Cox proportional hazards model with discrete ties was used for the statistical analysis, with covariates for both partners. A total of 1104 subjects took part, of whom 638 were occupationally exposed to lead at the relevant time. Blood lead levels were mainly less than 50 microg/dl. No consistent association of Time To Pregnancy with lead exposure was found in any of the exposure models, although reduced fertility was observed in one category each in models (2) and (3). This basically negative result is unlikely to be due to the misclassification of key variables, to insufficient statistical power, or to bias, for example, response bias. If any impairment of male reproductive function exists at the levels of occupational lead exposure now current, it does not appear to reduce biological fertility.

  10. HESI EXPOSURE FACTORS DATABASE FOR AGGREGATE AND CUMULATIVE RISK ASSESSMENT

    EPA Science Inventory

    In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of inp...

  11. HESI EXPOSURE FACTORS DATABASE FOR AGGREGATE AND CUMULATIVE RISK ASSESSMENT

    EPA Science Inventory

    In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of inp...

  12. Cumulative effects from repeated exposures to ultraviolet radiation

    SciTech Connect

    Kaidbey, K.H.; Kligman, A.M.

    1981-05-01

    Repeated exposures to subliminal doses of UVR, given at 24-hr intervals, resulted in a lowering of the erythema threshold dose. At erythemogenically equivalent doses, UV-A was the most effective and UV-C the least. A similar and more pronounced effect was observed following repeated exposures to subthreshold doses of UV-A and topically applied 8-methoxypsoralen. These findings provide quantitative evidence for the cumulative nature of acute UVR damage in human skin.

  13. Violence exposure in multiple interpersonal domains: cumulative and differential effects.

    PubMed

    Margolin, Gayla; Vickerman, Katrina A; Oliver, Pamella H; Gordis, Elana B

    2010-08-01

    To examine dose-response effects of cumulative violence exposure including parent-to-youth aggression, marital physical aggression, and community violence, and to explore whether separate interpersonal domains of exposure differentially influence adverse outcomes. The present study uses parent-reports and child-reports of youth violence exposure from the first three waves of a prospective, longitudinal study of 103 community-based families. Outcomes were criterion levels (T score >or= 60) of somatic complaints, depressive symptoms, anxiety, over-arousal, aggression, delinquent behaviors, and presence versus absence of academic failure. After controlling for initial symptoms, income and parents' psychopathology, adjusted relative risks showed that marital aggression contributed uniquely to anxiety, and parent-to-youth aggression contributed uniquely to somatic complaints and aggression. All three domains significantly contributed to academic failure. With each one-point increase on the cumulative violence exposure index that summed across interpersonal domains and across time, there was an increased risk of more than 50% for meeting criterion levels of depressive symptoms and anxiety, and a 10%-25% increased risk for somatic complaints, delinquent behaviors, and academic failure. Significant curvilinear effects showed high cumulative violence increased risk of comorbid symptoms; 76% of youth with higher cumulative violence met thresholds on 3+ adverse outcomes, compared to 36% and 7% for youth with moderate and low violence exposure. These data highlight the importance of assessing violence exposure across multiple interpersonal domains and across time. Awareness of the contributions of violence exposure to common symptoms and particularly comorbid symptoms can inform interventions for wide-ranging adolescent problems. (c) 2010 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

  14. Cumulative radiation exposure in pediatric patients with congenital heart disease.

    PubMed

    Walsh, Mark A; Noga, Michelle; Rutledge, Jennifer

    2015-02-01

    Certain pediatric patients undergoing surgery for the most severe forms of congenital heart disease are exposed to high doses of ionizing radiation. The amount of cumulative radiation exposure from all modalities has not yet been evaluated. The purpose of our study was to evaluate the cumulative radiation exposure in a contemporary cohort of patients with congenital heart disease undergoing single-ventricle palliation. This is a single-center, retrospective study of pediatric patients undergoing Fontan completion between May 2005 and May 2010. Radiation exposure from all procedures including cardiac catheterizations, computed tomography (CT) scans, plain film radiography, and nuclear medicine scans was evaluated. Radiation dose was calculated as the dose area product (μGy m(2)) and was measured in all cardiac catheterizations, CT scans, and other imaging modalities. Seventy patients who underwent Fontan completion at a mean age of 3.6 ± 1.5 years (range 1.4-8 years) were included in the study. Mean number of chest X-rays was 32 ± 8 (range 10-285) with a mean cumulative total exposure of 1,320 μGy m(2) (range 480-12,960) per patient. Mean number of cardiac catheterizations was 2.45 ± 1.3 (range 1-8), and mean fluoroscopy and cine angiography exposures per case were 1,103 ± 245 and 1,412 ± 273 μGy m(2) giving a mean cumulative exposure of 9,054 μGy m(2) (range 2,515-201,200) per patient for all catheterizations. Mean number of CT scans performed was 0.44 ± 0.4 (0-11), and the mean exposure was 352 μGy m(2), giving a mean cumulative total of 154 μGy m(2) (range 0-3,872) per person. A total of five lung perfusion scans were carried out. Radiation exposure in patients with congenital heart disease undergoing single-ventricle palliation is quite variable. Most of the exposure to ionizing radiation occurs during cardiac catheterization. Strategies to utilize other imaging modalities such as MRI would decrease exposure in this particular group of patients who

  15. Stakeholder attitudes towards cumulative and aggregate exposure assessment of pesticides.

    PubMed

    Verbeke, Wim; Van Loo, Ellen J; Vanhonacker, Filiep; Delcour, Ilse; Spanoghe, Pieter; van Klaveren, Jacob D

    2015-05-01

    This study evaluates the attitudes and perspectives of different stakeholder groups (agricultural producers, pesticide manufacturers, trading companies, retailers, regulators, food safety authorities, scientists and NGOs) towards the concepts of cumulative and aggregate exposure assessment of pesticides by means of qualitative in-depth interviews (n = 15) and a quantitative stakeholder survey (n = 65). The stakeholders involved generally agreed that the use of chemical pesticides is needed, primarily for meeting the need of feeding the growing world population, while clearly acknowledging the problematic nature of human exposure to pesticide residues. Current monitoring was generally perceived to be adequate, but the timeliness and consistency of monitoring practices across countries were questioned. The concept of cumulative exposure assessment was better understood by stakeholders than the concept of aggregate exposure assessment. Identified pitfalls were data availability, data limitations, sources and ways of dealing with uncertainties, as well as information and training needs. Regulators and food safety authorities were perceived as the stakeholder groups for whom cumulative and aggregate pesticide exposure assessment methods and tools would be most useful and acceptable. Insights obtained from this exploratory study have been integrated in the development of targeted and stakeholder-tailored dissemination and training programmes that were implemented within the EU-FP7 project ACROPOLIS.

  16. Childhood poverty and young adults' allostatic load: the mediating role of childhood cumulative risk exposure.

    PubMed

    Evans, Gary W; Kim, Pilyoung

    2012-09-01

    Childhood poverty is linked to a host of physical and psychological disorders during childhood and later in life. In the study reported here, we showed that the proportion of childhood spent in poverty from birth to age 9 was linked to elevated allostatic load, a marker of chronic physiological stress, in 17-year-olds. Furthermore, this prospective longitudinal relationship was mediated by cumulative risk exposure at age 13. The greater the duration of early life spent in poverty, the greater the exposure to cumulative risk. This, in turn, leads to elevated allostatic load. Multiple psychological, biological, and neurological pathways likely account for the social patterning of psychological and physical disease.

  17. Evaluation of cumulative lead dose and longitudinal changes in structural MRI in former organolead workers

    PubMed Central

    Schwartz, Brian S.; Caffo, Brian; Stewart, Walter F.; Hedlin, Haley; James, Bryan D.; Yousem, David; Davatzikos, Christos

    2010-01-01

    Objective We evaluated whether tibia lead was associated with longitudinal change in brain volumes and white matter lesions in male former lead workers and population-based controls in whom we have previously reported on the cognitive and structural consequences of cumulative lead dose. Methods We used linear regression to identify predictors of change in brain volumes and white matter lesion grade scores, using two MRIs an average of five years apart. Results On average, total brain volume declined almost 30 cm3, predominantly in gray matter. Increasing age at the first MRI was strongly associated with larger declines in volumes and greater increases in white matter lesion scores. Tibia lead was not associated with change in brain volumes or white matter lesion scores. Conclusions In former lead workers in whom cumulative lead dose was associated with progressive declines in cognitive function decades after occupational exposure had ended, cumulative lead dose was associated with earlier persistent effects on brain structure, but not with additional worsening over five years. PMID:20357679

  18. Early Childhood Poverty, Cumulative Risk Exposure, and Body Mass Index Trajectories Through Young Adulthood

    PubMed Central

    Evans, Gary W.; Beavis, Anna; Ong, Anthony D.

    2010-01-01

    Objectives. We assessed whether cumulative risk exposure underlies the relation between early childhood poverty and body mass index (BMI) trajectories. Methods. We interviewed youths and their mothers in rural upstate New York (168 boys and 158 girls) from 1995 to 2006 when the youths were aged 9, 13, and 17 years. At each interview, we calculated their BMI-for-age percentile. Results. Early childhood poverty predicted BMI growth trajectories from ages 9 to 17 years (b = 3.64; SE = 1.39; P < .01). Early childhood poverty also predicted changes in cumulative risk (b = 0.31; SE = 0.08; P < .001). Cumulative risk, in turn, predicted BMI trajectories (b = 2.41; SE = 0.75; P < .01). Finally, after we controlled for cumulative risk, the effect of early childhood poverty on BMI trajectories was no longer significant, indicating that cumulative risk exposure mediated the relation between early childhood poverty and BMI trajectories (b = 2.01; SE = 0.94). Conclusions. We show for the first time that early childhood poverty leads to accelerated weight gain over the course of childhood into early adulthood. Cumulative risk exposure during childhood accounts for much of this accelerated weight gain. PMID:20966374

  19. Early childhood poverty, cumulative risk exposure, and body mass index trajectories through young adulthood.

    PubMed

    Wells, Nancy M; Evans, Gary W; Beavis, Anna; Ong, Anthony D

    2010-12-01

    We assessed whether cumulative risk exposure underlies the relation between early childhood poverty and body mass index (BMI) trajectories. We interviewed youths and their mothers in rural upstate New York (168 boys and 158 girls) from 1995 to 2006 when the youths were aged 9, 13, and 17 years. At each interview, we calculated their BMI-for-age percentile. Early childhood poverty predicted BMI growth trajectories from ages 9 to 17 years (b = 3.64; SE = 1.39; P < .01). Early childhood poverty also predicted changes in cumulative risk (b = 0.31; SE = 0.08; P < .001). Cumulative risk, in turn, predicted BMI trajectories (b = 2.41; SE = 0.75; P < .01). Finally, after we controlled for cumulative risk, the effect of early childhood poverty on BMI trajectories was no longer significant, indicating that cumulative risk exposure mediated the relation between early childhood poverty and BMI trajectories (b = 2.01; SE = 0.94). We show for the first time that early childhood poverty leads to accelerated weight gain over the course of childhood into early adulthood. Cumulative risk exposure during childhood accounts for much of this accelerated weight gain.

  20. DETERMINANTS OF RESIDENTIAL LEAD EXPOSURE

    EPA Science Inventory

    The phase-out of leaded gasoline, and the accompanying decrease in lead emissions, resulted in a dramatic decline in mean blood lead levels from the late 1970s through the early 1990s. Nonetheless, lead exposures remain a public health concern. Long-term exposures to even low...

  1. DETERMINANTS OF RESIDENTIAL LEAD EXPOSURE

    EPA Science Inventory

    The phase-out of leaded gasoline, and the accompanying decrease in lead emissions, resulted in a dramatic decline in mean blood lead levels from the late 1970s through the early 1990s. Nonetheless, lead exposures remain a public health concern. Long-term exposures to even low...

  2. Cumulative dietary exposure of the population of Denmark to pesticides.

    PubMed

    Jensen, Bodil Hamborg; Petersen, Annette; Nielsen, Elsa; Christensen, Tue; Poulsen, Mette Erecius; Andersen, Jens Hinge

    2015-09-01

    We used the Hazard Index (HI) method to carry out a cumulative risk assessment after chronic dietary exposure to all monitored pesticides in fruit, vegetables and cereals for various consumer groups in Denmark. Residue data for all the pesticides were obtained from the Danish monitoring programme during the period 2004-2011. Food consumption data were obtained from DANSDA (the DAnish National Survey of Diet and physical Activity) for the period 2005-2008. The calculations were made using three different models to cope with residues below the limit of reporting (LOR). We concluded that a model that included processing factors and set non-detects to ½ LOR, but limited the correction (Model 3), gave the most realistic exposure estimate. With Model 3 the HI was calculated to be 0.44 for children and 0.18 for adults, indicating that there is no risk of adverse health effects following chronic cumulative exposure to the pesticides found in fruit, vegetables and cereals on the Danish market. The HI was below 1 even for consumers who eat more than 550 g of fruit and vegetables per day, corresponding to 1/3 of the population. Choosing Danish-produced commodities whenever possible could reduce the HI by a factor of 2. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Implantable magnetic relaxation sensors measure cumulative exposure to cardiac biomarkers.

    PubMed

    Ling, Yibo; Pong, Terrence; Vassiliou, Christophoros C; Huang, Paul L; Cima, Michael J

    2011-03-01

    Molecular biomarkers can be used as objective indicators of pathologic processes. Although their levels often change over time, their measurement is often constrained to a single time point. Cumulative biomarker exposure would provide a fundamentally different kind of measurement to what is available in the clinic. Magnetic resonance relaxometry can be used to noninvasively monitor changes in the relaxation properties of antibody-coated magnetic particles when they aggregate upon exposure to a biomarker of interest. We used implantable devices containing such sensors to continuously profile changes in three clinically relevant cardiac biomarkers at physiological levels for up to 72 h. Sensor response differed between experimental and control groups in a mouse model of myocardial infarction and correlated with infarct size. Our prototype for a biomarker monitoring device also detected doxorubicin-induced cardiotoxicity and can be adapted to detect other molecular biomarkers with a sensitivity as low as the pg/ml range.

  4. Modeling community asbestos exposure near a vermiculite processing facility: Impact of human activities on cumulative exposure.

    PubMed

    Adgate, John L; Cho, Sook Ja; Alexander, Bruce H; Ramachandran, Gurmurthy; Raleigh, Katherine K; Johnson, Jean; Messing, Rita B; Williams, A L; Kelly, James; Pratt, Gregory C

    2011-01-01

    Contaminated vermiculite ore from Libby, Montana was processed in northeast Minneapolis from 1936 to 1989 in a densely populated urban residential neighborhood, resulting in non-occupational exposure scenarios from plant stack and fugitive emissions as well as from activity-based scenarios associated with use of the waste rock in the surrounding community. The objective of this analysis was to estimate potential cumulative asbestos exposure for all non-occupationally exposed members of this community. Questionnaire data from a neighborhood-exposure assessment ascertained frequency of potential contact with vermiculite processing waste. Monte Carlo simulation was used to develop exposure estimates based on activity-based concentration estimates and contact durations for four scenarios: S1, moved asbestos-contaminated waste; S2, used waste at home, on lawn or garden; S3, installed/removed vermiculite insulation; S4, played in or around waste piles at the plant. The simulation outputs were combined with air-dispersion model results to provide total cumulative asbestos exposure estimates for the cohort. Fiber emissions from the plant were the largest source of exposure for the majority of the cohort, with geometric mean cumulative exposures of 0.02 fibers/cc × month. The addition of S1, S2 and S3 did not significantly increase total cumulative exposure above background exposure estimates obtained from dispersion modeling. Activity-based exposures were a substantial contributor to the upper end of the exposure distribution: 90th percentile S4 exposure estimates are ∼10 times higher than exposures from plant emissions. Pile playing is the strongest source of asbestos exposure in this cohort, with other activity scenarios contributing less than from plant emissions.

  5. Lead Aprons Are a Lead Exposure Hazard.

    PubMed

    Burns, Kevin M; Shoag, Jamie M; Kahlon, Sukhraj S; Parsons, Patrick J; Bijur, Polly E; Taragin, Benjamin H; Markowitz, Morri

    2017-05-01

    To determine whether lead-containing shields have lead dust on the external surface. Institutional review board approval was obtained for this descriptive study of a convenience sample of 172 shields. Each shield was tested for external lead dust via a qualitative rapid on-site test and a laboratory-based quantitative dust wipe analysis, flame atomic absorption spectrometry (FAAS). The χ(2) test was used to test the association with age, type of shield, lead sheet thickness, storage method, and visual and radiographic appearance. Sixty-three percent (95% confidence interval [CI]: 56%-70%) of the shields had detectable surface lead by FAAS and 50% (95% CI: 43%-57%) by the qualitative method. Lead dust by FAAS ranged from undetectable to 998 μg/ft(2). The quantitative detection of lead was significantly associated with the following: (1) visual appearance of the shield (1 = best, 3 = worst): 88% of shields that scored 3 had detectable dust lead; (2) type of shield: a greater proportion of the pediatric patient, full-body, and thyroid shields were positive than vests and skirts; (3) use of a hanger for storage: 27% of shields on a hanger were positive versus 67% not on hangers. Radiographic determination of shield intactness, thickness of interior lead sheets, and age of shield were unrelated to presence of surface dust lead. Sixty-three percent of shields had detectable surface lead that was associated with visual appearance, type of shield, and storage method. Lead-containing shields are a newly identified, potentially widespread source of lead exposure in the health industry. Copyright © 2016 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  6. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling

    NASA Astrophysics Data System (ADS)

    Li, Huanan; Agarwalla, Bijay Kumar; Wang, Jian-Sheng

    2012-10-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas.

  7. Childhood and Adult Socioeconomic Position, Cumulative Lead Levels, and Pessimism in Later Life

    PubMed Central

    Peters, Junenette L.; Kubzansky, Laura D.; Ikeda, Ai; Spiro, Avron; Wright, Robert O.; Weisskopf, Marc G.; Kim, Daniel; Sparrow, David; Nie, Linda H.; Hu, Howard; Schwartz, Joel

    2011-01-01

    Pessimism, a general tendency toward negative expectancies, is a risk factor for depression and also heart disease, stroke, and reduced cancer survival. There is evidence that individuals with higher lead exposure have poorer health. However, low socioeconomic status (SES) is linked with higher lead levels and greater pessimism, and it is unclear whether lead influences psychological functioning independently of other social factors. The authors considered interrelations among childhood and adult SES, lead levels, and psychological functioning in data collected on 412 Boston area men between 1991 and 2002 in a subgroup of the VA Normative Aging Study. Pessimism was measured by using the Life Orientation Test. Cumulative (tibia) lead was measured by x-ray fluorescence. Structural equation modeling was used to quantify the relations as mediated by childhood and adult SES, controlling for age, health behaviors, and health status. An interquartile range increase in lead quartile was associated with a 0.37 increase in pessimism score (P < 0.05). Low childhood and adult SES were related to higher tibia lead levels, and both were also independently associated with higher pessimism. Lead maintained an independent association with pessimism even after childhood and adult SES were considered. Results demonstrate an interrelated role of lead burden and SES over the life course in relation to psychological functioning in older age. PMID:22071587

  8. Respiratory exposures associated with silicon carbide production: estimation of cumulative exposures for an epidemiological study.

    PubMed Central

    Smith, T J; Hammond, S K; Laidlaw, F; Fine, S

    1984-01-01

    Silicon carbide is produced by heating a mixture of petroleum coke and silica sand to approximately 2000 degrees C in an electric furnace for 36 hours. During heating, large amounts of carbon monoxide are released, sulphur dioxide is produced from residual sulphur in the coke, and hydrocarbon fume is produced by pyrolysis of the coke. Loading and unloading furnaces causes exposures to respirable dust containing crystalline silica, silicon carbide, and hydrocarbons. In the autumn of 1980 extensive measurements were made of personal exposures to air contaminants. Eight hour time weighted exposures to sulphur dioxide ranged from less than 0.1 ppm to 1.5 ppm and respirable participate exposures ranged from 0.01 mg/m3 to 9.0 mg/m3. Geometric mean particulate exposures for jobs ranged from 0.1 mg/m3 to 1.46 mg/m3. The particulate contained varying amounts of alpha-quartz, ranging from less than 1% to 17%, and most quartz exposures were substantially below the threshold limit value of 100 micrograms/m3. Only traces of cristobalite (less than 1%) were found in the particulate. Median exposures to air contaminants in each job were estimated. Since the operations at the plant had been stable over the past 30 years, it was possible to estimate long term exposures of workers to sulphur dioxide, respirable particulate, quartz, total inorganic material, and extractable organic material. Cumulative exposure (average concentration times exposure duration) for each of the air contaminants was estimated for each worker using his job history. There was sufficient independent variability in the sulphur dioxide and respirable particulate cumulative exposures to make an assessment of their independent effects feasible. The theoretical basis for using the cumulative exposure index and its shortcomings for epidemiological applications were presented. PMID:6691927

  9. Relationship of cumulative dust exposure dose and cumulative abnormal rate of pulmonary function in coal mixture workers.

    PubMed

    Qian, Qing-Zeng; Cao, Xiang-Ke; Qian, Qing-Qiang; Shen, Fu-Hai; Wang, Qian; Liu, Hai-Yan; Tong, Jun-Wang

    2016-01-01

    To investigate the dose-response relationship between cumulative dust exposure (CDE) and cumulative abnormal rate of pulmonary function in coal mixture workers. Three hundred and twenty eight coal mixture workers (exposed group) and 169 nondust-exposed workers (control group) were recruited. Basic information data were collected and pulmonary function tests were performed. Pulmonary function was compared between the two groups after comparing smoking behaviors. Pulmonary function indices [forced vital capacity in 1 second after full inspiration (FVC)%, forced expiratory volume (FEV)1%, and FEV1/FVC%] were compared among groups stratified by service length (exposure duration). The relationship between CDE dose and cumulative abnormal rate of pulmonary function in coal mixture workers was analyzed. Abnormal rate of pulmonary function in the exposed group (35.1%) was significantly higher than the control group (10.1%; p < 0.001); FVC%, FEV1%, and FEV1/FVC% in the exposed group decreased significantly compared with the control group (all p < 0.05). Differences in FVC%, FEV1%, and FEV1/FVC% among coal mixture workers stratified by exposure duration in the exposed group were statistically significant (all p < 0.05). The discernible increase in the cumulative abnormal rate was observed, from ≥ 1000 mg/m(3)·years group to ≥ 1700 mg/m(3)·years group. Correlation analysis revealed a positive correlation between the CDE dose and the cumulative abnormal rate of pulmonary function. Higher abnormal pulmonary function rate was found among coal mixture workers, characterized by decreased pulmonary function indices. Our results suggested a positive relationship between CDE dose and cumulative abnormal pulmonary function rate, and a rapid increase in cumulative abnormal rate within a certain range of CDE dose. A lower limit value of 1000 mg/m(3)·years has reference significance. Copyright © 2015. Published by Elsevier Taiwan.

  10. Evaluation of cumulative PCB exposure estimated by a job exposure matrix versus PCB serum concentrations.

    PubMed

    Hopf, Nancy B; Ruder, Avima M; Succop, Paul; Waters, Martha A

    2014-05-01

    Although polychlorinated biphenyls (PCBs) have been banned in many countries for more than three decades, exposures to PCBs continue to be of concern due to their long half-lives and carcinogenic effects. In National Institute for Occupational Safety and Health studies, we are using semiquantitative plant-specific job exposure matrices (JEMs) to estimate historical PCB exposures for workers (n = 24,865) exposed to PCBs from 1938 to 1978 at three capacitor manufacturing plants. A subcohort of these workers (n = 410) employed in two of these plants had serum PCB concentrations measured at up to four times between 1976 and 1989. Our objectives were to evaluate the strength of association between an individual worker's measured serum PCB levels and the same worker's cumulative exposure estimated through 1977 with the (1) JEM and (2) duration of employment, and to calculate the explained variance the JEM provides for serum PCB levels using (3) simple linear regression. Consistent strong and statistically significant associations were observed between the cumulative exposures estimated with the JEM and serum PCB concentrations for all years. The strength of association between duration of employment and serum PCBs was good for highly chlorinated (Aroclor 1254/HPCB) but not less chlorinated (Aroclor 1242/LPCB) PCBs. In the simple regression models, cumulative occupational exposure estimated using the JEMs explained 14-24% of the variance of the Aroclor 1242/LPCB and 22-39% for Aroclor 1254/HPCB serum concentrations. We regard the cumulative exposure estimated with the JEM as a better estimate of PCB body burdens than serum concentrations quantified as Aroclor 1242/LPCB and Aroclor 1254/HPCB.

  11. Evaluation of cumulative PCB exposure estimated by a job exposure matrix versus PCB serum concentrations

    PubMed Central

    Ruder, Avima M.; Succop, Paul; Waters, Martha A.

    2015-01-01

    Although polychlorinated biphenyls (PCBs) have been banned in many countries for more than three decades, exposures to PCBs continue to be of concern due to their long half-lives and carcinogenic effects. In National Institute for Occupational Safety and Health studies, we are using semiquantitative plant-specific job exposure matrices (JEMs) to estimate historical PCB exposures for workers (n=24,865) exposed to PCBs from 1938 to 1978 at three capacitor manufacturing plants. A subcohort of these workers (n=410) employed in two of these plants had serum PCB concentrations measured at up to four times between 1976 and 1989. Our objectives were to evaluate the strength of association between an individual worker’s measured serum PCB levels and the same worker’s cumulative exposure estimated through 1977 with the (1) JEM and (2) duration of employment, and to calculate the explained variance the JEM provides for serum PCB levels using (3) simple linear regression. Consistent strong and statistically significant associations were observed between the cumulative exposures estimated with the JEM and serum PCB concentrations for all years. The strength of association between duration of employment and serum PCBs was good for highly chlorinated (Aroclor 1254/HPCB) but not less chlorinated (Aroclor 1242/LPCB) PCBs. In the simple regression models, cumulative occupational exposure estimated using the JEMs explained 14–24 % of the variance of the Aroclor 1242/LPCB and 22–39 % for Aroclor 1254/HPCB serum concentrations. We regard the cumulative exposure estimated with the JEM as a better estimate of PCB body burdens than serum concentrations quantified as Aroclor 1242/LPCB and Aroclor 1254/HPCB. PMID:23475397

  12. Reducing lead exposure in children

    SciTech Connect

    Farfel, M.R.

    1985-01-01

    The near elimination of lead-related childhood fatalities and encephalopathy by the 1970s and the sharp decline in mean blood lead levels nationwide documented between 1976 and 1980 are two milestones in the fight against lead poisoning. In the case of the latter, we know the antecedents, such as controls on the sale, use, and lead content of lead paint, improved chelation therapy, and increased awareness and case finding; however, the antecedents' relative contributions are not known due to a lack of evaluation. Similarly, the effect of a variety of social-welfare programs has not been evaluated. Since the 1970s, our perception of the problem of lead toxicity and consequently its control has changed. First steps have been made toward attaining one primary preventive objective, controlling the multiple sources of new inputs of lead to the biosphere that contribute to asymptomatic lead toxicity. The lead content of widely used commodities has been reduced (canned foods and gasoline) or virtually eliminated (paint). The benefits of passive measures used to attain reductions in lead exposure have been documented to a greater extent than those of active programs. The best example of a successful primary and passive preventive measure is the availability of lead-free gasoline since 1974, which largely accounts for decreases in ambient air lead concentrations nationwide and the recent shift to lower values in the distribution curve of children's blood lead levels. The latter provides a margin of safety for children before known toxic levels are reached. The contribution of reductions in dietary lead to changes in blood lead levels has not been well documented. Studies also show the benefits of the use of lead-free paint in new housing. Compared to children living in older homes with deteriorating lead paint, those living in lead-free homes are at low risk for lead toxicity.

  13. Neighborhood Psychosocial Hazards and the Association of Cumulative Lead Dose With Cognitive Function in Older Adults

    PubMed Central

    Bandeen-Roche, Karen; McAtee, Matthew; Bolla, Karen; Todd, Andrew C.; Schwartz, Brian S.

    2009-01-01

    Before the 1970s, today's older Americans were exposed to high levels of lead in the environment. The authors previously reported that lifetime cumulative lead dose was associated with lower cognitive test performance in older adults. Experiments suggest that environmental stress may intensify the detrimental influence of lead. No large, population-based studies of this question have been done. The authors evaluated whether cross-sectional associations of tibia lead with cognitive function were modified by neighborhood psychosocial hazards in the Baltimore Memory Study (2001–2005), a longitudinal cohort study of determinants of cognitive decline. Tibia lead was measured via 109Cd-induced K-shell X-ray fluorescence. Neighborhood psychosocial hazards were measured independently of study subjects. Complete data were available among 1,001 demographically diverse adults aged 50–70 years, randomly selected from 65 contiguous neighborhoods in Baltimore City. Hierarchical mixed-effects regression models showed that neighborhood psychosocial hazards exacerbated the adverse associations of tibia lead in 3 of 7 cognitive domains after adjustment for age, sex, race/ethnicity, education, testing technician, and time of day (language, P = 0.039; processing speed, P = 0.067; executive functioning, P = 0.025). The joint occurrence of environmental stress and lead exposure across the life span may partially explain persistent racial/ethnic and socioeconomic disparities in cognitive function in late life. PMID:19155330

  14. Cumulative health risk assessment: integrated approaches for multiple contaminants, exposures, and effects

    SciTech Connect

    Rice, Glenn; Teuschler, Linda; MacDonel, Margaret; Butler, Jim; Finster, Molly; Hertzberg, Rick; Harou, Lynne

    2007-07-01

    Available in abstract form only. Full text of publication follows: As information about environmental contamination has increased in recent years, so has public interest in the combined effects of multiple contaminants. This interest has been highlighted by recent tragedies such as the World Trade Center disaster and hurricane Katrina. In fact, assessing multiple contaminants, exposures, and effects has long been an issue for contaminated sites, including U.S. Department of Energy (DOE) legacy waste sites. Local citizens have explicitly asked the federal government to account for cumulative risks, with contaminants moving offsite via groundwater flow, surface runoff, and air dispersal being a common emphasis. Multiple exposures range from ingestion and inhalation to dermal absorption and external gamma irradiation. Three types of concerns can lead to cumulative assessments: (1) specific sources or releases - e.g., industrial facilities or accidental discharges; (2) contaminant levels - in environmental media or human tissues; and (3) elevated rates of disease - e.g., asthma or cancer. The specific initiator frames the assessment strategy, including a determination of appropriate models to be used. Approaches are being developed to better integrate a variety of data, extending from environmental to internal co-location of contaminants and combined effects, to support more practical assessments of cumulative health risks. (authors)

  15. Tools to Assess Community-Based Cumulative Risk and Exposures

    EPA Science Inventory

    Multiple agents and stressors can interact in a given community to adversely affect human and ecological conditions. A cumulative risk assessment (CRA) analyzes, characterizes, and potentially quantifies the effects from multiple stressors, which include chemical agents (for exam...

  16. Tools to Assess Community-Based Cumulative Risk and Exposures

    EPA Science Inventory

    Multiple agents and stressors can interact in a given community to adversely affect human and ecological conditions. A cumulative risk assessment (CRA) analyzes, characterizes, and potentially quantifies the effects from multiple stressors, which include chemical agents (for exam...

  17. Estimating greenspace exposure and benefits for cumulative risk assessment applications

    Treesearch

    Rebecca Gernes; Richard Hertzberg; Margaret MacDonell; Glenn Rice; J. Michael Wright; Glennon Beresin; Travis Miller; Julia Africa; Geoffrey Donovan; J. Aaron Hipp; Perry Hystad; Laura Jackson; Michelle Kondo; Richard Mitchell; Mark Nieuwenhuijsen; Patrick Ryan; William Sullivan; Matilda Annerstedt. van den Bosch

    2016-01-01

    This document provides a summary of the technical meeting on greenspace and cumulative risk assessment (GS-CRA) convened May 4−5, 2015 in Cincinnati, OH, by the U.S. Environmental Protection Agency (EPA) Office of Research and Development (ORD) National Center for Environmental Assessment (NCEA). This report highlights the presentations, discussions, and practical...

  18. Estimation of cumulative exposures to naphtha at an automobile fuel-injector manufacturing plant.

    PubMed

    Rocskay, A Z; Robins, T G; Echeverria, D; Schork, M A; Seixas, N S; White, R F; Proctor, S P

    1993-09-01

    As part of an epidemiologic study of neuropsychological and renal effects of occupational exposure to organic solvents, estimates of cumulative exposure to naphtha were derived for workers at an automobile fuel-injector manufacturing plant. The approach to exposure estimation was relatively unusual in three respects: (1) a marked association between indoor naphtha air concentration and outdoor temperature was modeled and applied to detailed historical temperature data to calculate cumulative exposure estimates; (2) the large number of investigator-generated air samples allowed the use of analyses of variance to compare alternative job-grouping schemes; and (3) the young age of the plant and few process changes allowed for historical exposure estimates with a high degree of confidence. The derived estimates of cumulative exposure appear to offer a firm basis for epidemiologic analyses of exposure-health outcome relationships.

  19. A Conceptual Framework for the Assessment of Cumulative Exposure to Air Pollution at a Fine Spatial Scale

    PubMed Central

    Wahida, Kihal-Talantikite; Padilla, Cindy M.; Denis, Zmirou-Navier; Olivier, Blanchard; Géraldine, Le Nir; Philippe, Quenel; Séverine, Deguen

    2016-01-01

    Many epidemiological studies examining long-term health effects of exposure to air pollutants have characterized exposure by the outdoor air concentrations at sites that may be distant to subjects’ residences at different points in time. The temporal and spatial mobility of subjects and the spatial scale of exposure assessment could thus lead to misclassification in the cumulative exposure estimation. This paper attempts to fill the gap regarding cumulative exposure assessment to air pollution at a fine spatial scale in epidemiological studies investigating long-term health effects. We propose a conceptual framework showing how major difficulties in cumulative long-term exposure assessment could be surmounted. We then illustrate this conceptual model on the case of exposure to NO2 following two steps: (i) retrospective reconstitution of NO2 concentrations at a fine spatial scale; and (ii) a novel approach to assigning the time-relevant exposure estimates at the census block level, using all available data on residential mobility throughout a 10- to 20-year period prior to that for which the health events are to be detected. Our conceptual framework is both flexible and convenient for the needs of different epidemiological study designs. PMID:26999170

  20. A Conceptual Framework for the Assessment of Cumulative Exposure to Air Pollution at a Fine Spatial Scale.

    PubMed

    Wahida, Kihal-Talantikite; Padilla, Cindy M; Denis, Zmirou-Navier; Olivier, Blanchard; Géraldine, Le Nir; Philippe, Quenel; Séverine, Deguen

    2016-03-15

    Many epidemiological studies examining long-term health effects of exposure to air pollutants have characterized exposure by the outdoor air concentrations at sites that may be distant to subjects' residences at different points in time. The temporal and spatial mobility of subjects and the spatial scale of exposure assessment could thus lead to misclassification in the cumulative exposure estimation. This paper attempts to fill the gap regarding cumulative exposure assessment to air pollution at a fine spatial scale in epidemiological studies investigating long-term health effects. We propose a conceptual framework showing how major difficulties in cumulative long-term exposure assessment could be surmounted. We then illustrate this conceptual model on the case of exposure to NO₂ following two steps: (i) retrospective reconstitution of NO₂ concentrations at a fine spatial scale; and (ii) a novel approach to assigning the time-relevant exposure estimates at the census block level, using all available data on residential mobility throughout a 10- to 20-year period prior to that for which the health events are to be detected. Our conceptual framework is both flexible and convenient for the needs of different epidemiological study designs.

  1. Exposure Assessment Tools by Tiers and Types - Aggregate and Cumulative

    EPA Pesticide Factsheets

    EPA ExpoBox is a toolbox for exposure assessors. Its purpose is to provide a compendium of exposure assessment and risk characterization tools that will present comprehensive step-by-step guidance and links to relevant exposure assessment data bases

  2. Effects of occupational lead exposure.

    PubMed

    Wang, Y L; Lu, P K; Chen, Z Q; Liang, Y X; Lu, Q M; Pan, Z Q; Shao, M

    1985-01-01

    Fifty-three workers in a battery factory, 52 solderers in a television factory, and 50 embroidery workers (a reference group) were studied. The average air lead levels of the three workplaces were 0.578 mg/m3, 0.002 mg/m3, and 0.001 mg/m3, respectively. Adverse effects in terms of clinical manifestations and biochemical criteria were evident among the battery factory workers. A significant dose-response relationship existed between the toxic effects and the air lead levels. The solderers showed no apparent abnormalities in comparison with the embroidery workers. The early clinical manifestations were dysfunction of the central nervous system, indigestion, arthralgia, and myalgia in the extremities. A positive association was observed between the prevalence of fatigue, mild abdominal pain, and arthralgia and the blood lead (PbB), urinary lead (PbU), and zinc protoporphyrin (ZPP) levels. The symptomatic threshold values of PbB, PbU, and ZPP were 30 micrograms/dl (1.5 mumol/l), 0.045 mg/l (0.2 mumol/l), and 40 micrograms/dl (0.7 mumol/l), respectively. The PbB, PbU, free erythrocyte protoporphyrin, and ZPP levels and the blood aminolevulinic dehydratase ratio could be used as indicators of lead exposure, although ZPP is preferred for a preventive monitoring program. The motor and sensory conduction velocities of the median nerve were slower in the exposed groups than in the reference group. No effects on behavioral function were observed among the solderers.

  3. Methodologies for Estimating Cumulative Human Exposures to Current-Use Pyrethroid Pesticides

    EPA Science Inventory

    We estimated cumulative residential pesticide exposures for a group of nine young children (4–6 years) using three different methodologies developed by the US Environmental Protection Agency and compared the results with estimates derived from measured urinary metabolite concentr...

  4. Modeling Joint Exposures and Health Outcomes for Cumulative Risk Assessment: the Case of Radon and Smoking

    EPA Science Inventory

    Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case exam...

  5. Methodologies for Estimating Cumulative Human Exposures to Current-Use Pyrethroid Pesticides

    EPA Science Inventory

    We estimated cumulative residential pesticide exposures for a group of nine young children (4–6 years) using three different methodologies developed by the US Environmental Protection Agency and compared the results with estimates derived from measured urinary metabolite concentr...

  6. EXPOSURE ASSESSMENT TOOLS FOR CUMULATIVE RISK ASSESSMENT: MEASUREMENT OF ENDOGENOUS BIOMARKERS

    EPA Science Inventory

    Direct assessment of cumulative risks is a difficult task due to combinations of multiple chemicals, exposure pathways, and concentration profiles using suites of environmental measurements. We are investigating the use of endogenous compounds commonly present in biological medi...

  7. Modeling Joint Exposures and Health Outcomes for Cumulative Risk Assessment: the Case of Radon and Smoking

    EPA Science Inventory

    Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case exam...

  8. Biomarkers of lead exposure and DNA methylation within retrotransposons.

    PubMed

    Wright, Robert O; Schwartz, Joel; Wright, Rosalind J; Bollati, Valentina; Tarantini, Letizia; Park, Sung Kyun; Hu, Howard; Sparrow, David; Vokonas, Pantel; Baccarelli, Andrea

    2010-06-01

    DNA methylation is an epigenetic mark that regulates gene expression. Changes in DNA methylation within white blood cells may result from cumulative exposure to environmental metals such as lead. Bone lead, a marker of cumulative exposure, may therefore better predict DNA methylation than does blood lead. In this study we compared associations between lead biomarkers and DNA methylation. We measured global methylation in participants of the Normative Aging Study (all men) who had archived DNA samples. We measured patella and tibia lead levels by K-X-Ray fluorescence and blood lead by atomic absorption spectrophotometry. DNA samples from blood were used to determine global methylation averages within CpG islands of long interspersed nuclear elements-1 (LINE-1) and Alu retrotransposons. A mixed-effects model using repeated measures of Alu or LINE-1 as the dependent variable and blood/bone lead (tibia or patella in separate models) as the primary exposure marker was fit to the data. Overall mean global methylation (+/- SD) was 26.3 +/- 1.0 as measured by Alu and 76.8 +/- 1.9 as measured by LINE-1. In the mixed-effects model, patella lead levels were inversely associated with LINE-1 (beta = -0.25; p < 0.01) but not Alu (beta = -0.03; p = 0.4). Tibia lead and blood lead did not predict global methylation for either Alu or LINE-1. Patella lead levels predicted reduced global DNA methylation within LINE-1 elements. The association between lead exposure and LINE-1 DNA methylation may have implications for the mechanisms of action of lead on health outcomes, and also suggests that changes in DNA methylation may represent a biomarker of past lead exposure.

  9. Brainstem auditory evoked potentials in children with lead exposure.

    PubMed

    Alvarenga, Katia de Freitas; Morata, Thais Catalani; Lopes, Andrea Cintra; Feniman, Mariza Ribeiro; Corteletti, Lilian Cassia Bornia Jacob

    2015-01-01

    Earlier studies have demonstrated an auditory effect of lead exposure in children, but information on the effects of low chronic exposures needs to be further elucidated. To investigate the effect of low chronic exposures of the auditory system in children with a history of low blood lead levels, using an auditory electrophysiological test. Contemporary cross-sectional cohort. Study participants underwent tympanometry, pure tone and speech audiometry, transient evoked otoacoustic emissions, and brainstem auditory evoked potentials, with blood lead monitoring over a period of 35.5 months. The study included 130 children, with ages ranging from 18 months to 14 years, 5 months (mean age 6 years, 8 months ± 3 years, 2 months). The mean time-integrated cumulative blood lead index was 12 μg/dL (SD ± 5.7, range: 2.433). All participants had hearing thresholds equal to or below 20 dBHL and normal amplitudes of transient evoked otoacoustic emissions. No association was found between the absolute latencies of waves I, III, and V, the interpeak latencies I-III, III-V, and I-V, and the cumulative lead values. No evidence of toxic effects from chronic low lead exposures was observed on the auditory function of children living in a lead contaminated area. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  10. Relative pesticide and exposure route contribution to aggregate and cumulative dose in young farmworker children.

    PubMed

    Beamer, Paloma I; Canales, Robert A; Ferguson, Alesia C; Leckie, James O; Bradman, Asa

    2012-01-01

    The Child-Specific Aggregate Cumulative Human Exposure and Dose (CACHED) framework integrates micro-level activity time series with mechanistic exposure equations, environmental concentration distributions, and physiologically-based pharmacokinetic components to estimate exposure for multiple routes and chemicals. CACHED was utilized to quantify cumulative and aggregate exposure and dose estimates for a population of young farmworker children and to evaluate the model for chlorpyrifos and diazinon. Micro-activities of farmworker children collected concurrently with residential measurements of pesticides were used in the CACHED framework to simulate 115,000 exposure scenarios and quantify cumulative and aggregate exposure and dose estimates. Modeled metabolite urine concentrations were not statistically different than concentrations measured in the urine of children, indicating that CACHED can provide realistic biomarker estimates. Analysis of the relative contribution of exposure route and pesticide indicates that in general, chlorpyrifos non-dietary ingestion exposure accounts for the largest dose, confirming the importance of the micro-activity approach. The risk metrics computed from the 115,000 simulations, indicate that greater than 95% of these scenarios might pose a risk to children's health from aggregate chlorpyrifos exposure. The variability observed in the route and pesticide contributions to urine biomarker levels demonstrate the importance of accounting for aggregate and cumulative exposure in establishing pesticide residue tolerances in food.

  11. Dermal echogenicity: a biological indicator of individual cumulative UVR exposure?

    PubMed

    Sandby-Møller, Jane; Thieden, Elisabeth; Philipsen, Peter Alshede; Schmidt, Grethe; Wulf, Hans Christian

    2004-04-01

    Dermal alterations due to chronic UVR exposure may influence dermal ultrasound echogenicity, and a subepidermal low-echogenic band has been proposed as a marker of photoaging. The aim of this study was to determine whether dermal echogenicity could be used as a biological UVR dosimeter. We included 201 subjects (138 healthy volunteers, 31 patients with basal cell carcinoma, and 32 patients with cutaneous malignant melanoma). The number of low-echogenic pixels in the upper dermis relative to the lower dermis (LEP(u/l)) was determined in sun-exposed and sun-protected skin. Individual UVR exposure data were collected retrospectively and prospectively using a questionnaire and electronic personal UVR dosimeters. Age, but not sex, skin type, constitutive pigmentation or smoking, correlated significantly with LEP(u/l) at all body sites. Different measures of individual UVR exposure were significantly positively correlated with LEP(u/l) (together r(2)=0.39, dorsal forearm), but separately the correlations were poor ( r(2)=0.04-0.19). LEP(u/l) was higher in the dorsal forearm in a group with high UVR exposure compared to a low-exposure group ( P=0.007). Skin cancer patients in general had a lower LEP(u/l) than healthy subjects. The results indicate that the age-related increase in LEP(u/l) might be attributed mainly to UVR exposure, and that the methods used to obtain the UVR exposure data might not be sufficiently sensitive or specific. Genetic factors might also influence LEP(u/l). We consider LEP(u/l) to be a sensitive and specific marker for UVR exposure at the dorsal aspect of the forearm in healthy subjects.

  12. Tracking Cumulative Radiation Exposure in Orthopaedic Surgeons and Residents: What Dose Are We Getting?

    PubMed

    Gausden, Elizabeth B; Christ, Alexander B; Zeldin, Roseann; Lane, Joseph M; McCarthy, Moira M

    2017-08-02

    The purpose of this study was to determine the amount of cumulative radiation exposure received by orthopaedic surgeons and residents in various subspecialties. We obtained dosimeter measures over 12 months on 24 residents and 16 attending surgeons. Monthly radiation exposure was measured over a 12-month period for 24 orthopaedic residents and 16 orthopaedic attending surgeons. The participants wore a Landauer Luxel dosimeter on the breast pocket of their lead apron. The dosimeters were exchanged every rotation (5 to 7 weeks) for the resident participants and every month for the attending surgeon participants. Radiation exposure was compared by orthopaedic subspecialty, level of training, and type of fluoroscopy used (regular C-arm compared with mini C-arm). Orthopaedic residents participating in this study received monthly mean radiation exposures of 0.2 to 79 mrem/month, lower than the dose limits of 5,000 mrem/year recommended by the United States Nuclear Regulatory Commission (U.S. NRC). Senior residents rotating on trauma were exposed to the highest monthly radiation (79 mrem/month [range, 15 to 243 mrem/month]) compared with all other specialty rotations (p < 0.001). Similarly, attending orthopaedic surgeons who specialize in trauma or deformity surgery received the highest radiation exposure of their peers, and the mean exposure was 53 mrem/month (range, 0 to 355 mrem/month). Residents and attending surgeons performing trauma or deformity surgical procedures are exposed to significantly higher doses of radiation compared with all other subspecialties within orthopaedic surgery, but the doses are still within the recommended limits. The use of ionizing radiation in the operating room has become an indispensable part of orthopaedic surgery. Although all surgeons in our study received lower than the yearly recommended dose limit, it is important to be aware of how much radiation we are exposed to as surgeons and to take measures to further limit that exposure.

  13. Cumulative asbestos exposure for US automobile mechanics involved in brake repair (circa 1950s-2000).

    PubMed

    Finley, Brent L; Richter, Richard O; Mowat, Fionna S; Mlynarek, Steve; Paustenbach, Dennis J; Warmerdam, John M; Sheehan, Patrick J

    2007-11-01

    We analyzed cumulative lifetime exposure to chrysotile asbestos experienced by brake mechanics in the US during the period 1950-2000. Using Monte Carlo methods, cumulative exposures were calculated using the distribution of 8-h time-weighted average exposure concentrations for brake mechanics and the distribution of job tenure data for automobile mechanics. The median estimated cumulative exposures for these mechanics, as predicted by three probabilistic models, ranged from 0.16 to 0.41 fibers per cubic centimeter (f/cm(3)) year for facilities with no dust-control procedures (1970s), and from 0.010 to 0.012 f/cm(3) year for those employing engineering controls (1980s). Upper-bound (95%) estimates for the 1970s and 1980s were 1.96 to 2.79 and 0.07-0.10 f/cm(3) year, respectively. These estimates for US brake mechanics are consistent with, but generally slightly lower than, those reported for European mechanics. The values are all substantially lower than the cumulative exposure of 4.5 f/cm(3) year associated with occupational exposure to 0.1 f/cm(3) of asbestos for 45 years that is currently permitted under the current occupational exposure limits in the US. Cumulative exposures were usually about 100- to 1,000-fold less than those of other occupational groups with asbestos exposure for similar time periods. The cumulative lifetime exposure estimates presented here, combined with the negative epidemiology data for brake mechanics, could be used to refine the risk assessments for chrysotile-exposed populations.

  14. CUMULATIVE PM2.5 EXPOSURE AND TELOMERE LENGTH IN WORKERS EXPOSED TO WELDING FUMES

    PubMed Central

    Wong, Jason Y. Y.; De Vivo, Immaculata; Lin, Xihong; Christiani, David C.

    2014-01-01

    Telomeres are genomic structures that reflect both mitotic history and biochemical trauma to the genome. Metals inherent in fine particulate matter (PM2.5) were shown to be genotoxic via oxidative damage. However, few studies investigated the induction time of cumulative PM2.5 exposure on telomere length in a longitudinal setting. Therefore, the purpose of this study was to assess the association between occupational PM2.5 exposure in various time windows and telomere length. The study population consisted of 48 boilermakers and the follow-up period was 8 yr. The main exposures were cumulative occupational PM2.5 in the month, year, and career prior to each blood draw, assessed via work history questionnaires and area air measures. Repeated telomere length measurements from leukocytes were assessed via real-time quantitative polymerase chain reaction (qPCR). Analysis was performed using linear mixed models controlling for confounders and white blood cell differentials. Cumulative PM2.5 exposure was treated continuously and categorized into quartiles, in separate analyses. At any follow-up time, for each milligram per cubic meter per hour increase in cumulative PM2.5 exposure in the prior month, there was a statistically significant decrease in relative telomere length of −0.04 units. When categorizing the exposure into quartiles, there was a significant negative association between telomere length and highest quartile of cumulative PM2.5 exposure in the prior month (−0.16). These findings suggest that genomic trauma to leukocyte telomeres was more consistent with recent occupational PM2.5 exposure, as opposed to cumulative exposure extending into the distant past. PMID:24627998

  15. Lead exposure in a firing range.

    PubMed Central

    Novotny, T; Cook, M; Hughes, J; Lee, S A

    1987-01-01

    We report lead exposure in four employees of a privately owned shooting range, one of whom had neurological toxicity due to lead. Increasing time worked at the range was associated with elevation of blood lead. This incident emphasizes the risk of airborne lead exposure to employees of firing ranges. PMID:3618861

  16. Fetal Substance Exposure and Cumulative Environmental Risk in an African American Cohort

    ERIC Educational Resources Information Center

    Yumoto, Chie; Jacobson, Sandra W.; Jacobson, Joseph L.

    2008-01-01

    Two models of vulnerability to socioenvironmental risk were examined in 337 African American children (M = 7.8 years) recruited to overrepresent prenatal alcohol or cocaine exposure: The cumulative risk model predicted synergistic effects from exposure to multiple risk factors, and the fetal patterning of disease model predicted that prenatal…

  17. Fetal Substance Exposure and Cumulative Environmental Risk in an African American Cohort

    ERIC Educational Resources Information Center

    Yumoto, Chie; Jacobson, Sandra W.; Jacobson, Joseph L.

    2008-01-01

    Two models of vulnerability to socioenvironmental risk were examined in 337 African American children (M = 7.8 years) recruited to overrepresent prenatal alcohol or cocaine exposure: The cumulative risk model predicted synergistic effects from exposure to multiple risk factors, and the fetal patterning of disease model predicted that prenatal…

  18. Correlations of smoking with cumulative total dust exposure and cumulative abnormal rate of pulmonary function in coal-mine workers

    PubMed Central

    Qian, Qing-Zeng; Cao, Xiang-Ke; Shen, Fu-Hai; Wang, Qian

    2016-01-01

    The present study aimed to investigate the correlation of smoking with cumulative total dust exposure (CTE) and cumulative abnormal rate of pulmonary function in coal-mine workers. A total of 376 coal-mine workers were recruited as the observational group, while 179 healthy workers in other industries were selected as the control group. All the workers underwent pulmonary function testing to determine their forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and FEV1/FVC, in order to compare the abnormal pulmonary function between the two groups. A markedly higher number of smokers was observed in the observational group (200/376, 53.19%) when compared with the control group (72/179, 40.22%). In smokers, the abnormal rate of pulmonary function in the observational group (102/200, 51.00%) was evidently higher compared with that in the control group (19/72, 26.39%), whereas no significant difference was detected between the two groups of non-smokers (P=0.077). In addition, FVC, FEV1 and FEV1/FVC of the observational group were found to be lower compared with those in the control group, in both the smoking and non-smoking subgroups. In the smoking subgroup, FVC and FEV1 in subjects working at the coal mine for different number of years showed significant differences (all P<0.05), whereas comparison of FEV1/FVC in workers with different working durations showed no significant difference (P=0.169). However, in the non-smoking subgroup, the comparison of FVC, FEV1 and FEV1/FVC in different working duration groups also showed no significant difference (all P>0.05). Furthermore, FVC, FEV1 and FEV1/FVC in smoking coal-mine workers were negatively correlated with the dust-exposure working duration (P<0.05). CTE was also positively correlated with cumulative abnormal rate of pulmonary function in the smoking and non-smoking subgroups, while FEV1 was negatively correlated with CTE in the smoking subgroup (P=0.009). In conclusion, smoking is an important

  19. How cumulative risks warrant a shift in our approach to racial health disparities: the case of lead, stress, and hypertension.

    PubMed

    Hicken, Margaret; Gragg, Richard; Hu, Howard

    2011-10-01

    Blacks have persistently higher rates of high blood pressure, or hypertension, compared to whites, resulting in higher health costs and mortality rates. Recent research has shown that social and environmental factors-such as high levels of stress and exposure to lead-may explain racial disparities in hypertension. Based on these findings, we recommend a fundamental shift in approaches to health disparities to focus on these sorts of cumulative risks and health effects. Federal and state agencies and research institutions should develop strategic plans to learn more about these connections and apply the broader findings to policies to reduce health disparities.

  20. Is There an Association Between Lifetime Cumulative Exposure and Acute Pulmonary Responses to Ozone?

    PubMed Central

    Arjomandi, Mehrdad; Tager, Ira B.; Bastaki, Maria; Chen, Connie; Holland, Nina; Balmes, John R.

    2012-01-01

    Objective To investigate the potential effects of lifetime cumulative ozone (O3) exposure on acute pulmonary responses to O3. Methods Fifteen healthy subjects from a larger cohort of young adults were exposed to 200 ppb O3 for 4 hours followed by bronchoscopy and bronchoalveolar lavage 18 hours later. Lung function, symptom questionnaires, and blood samples were obtained before and after each exposure. Subjects’ lifetime cumulative O3 exposures were estimated from residential histories and air-quality monitoring data. Results Acute exposure to O3 caused decrements in forced expiratory volume in 1 second (FEV1), maximal mid-expiratory flow rate (FEF25–75), and forced expiratory flow rate at 75% of forced vital capacity (FEF75), and an increase in plasma clara cell protein (CC16) level. Changes in CC16 and lower respiratory symptoms, but not in lung function, were positively correlated with lifetime cumulative O3 exposure. Conclusion Higher lifetime cumulative O3 exposure was associated with airway injury and respiratory symptom responses, but not with airway inflammatory or lung function responses, to acute O3 exposure. PMID:18332784

  1. Is there an association between lifetime cumulative exposure and acute pulmonary responses to ozone?

    PubMed

    Arjomandi, Mehrdad; Tager, Ira B; Bastaki, Maria; Chen, Connie; Holland, Nina; Balmes, John R

    2008-03-01

    To investigate the potential effects of lifetime cumulative ozone (O3) exposure on acute pulmonary responses to O3. Fifteen healthy subjects from a larger cohort of young adults were exposed to 200 ppb O3 for 4 hours followed by bronchoscopy and bronchoalveolar lavage 18 hours later. Lung function, symptom questionnaires, and blood samples were obtained before and after each exposure. Subjects' lifetime cumulative O3 exposures were estimated from residential histories and air-quality monitoring data. Acute exposure to O3 caused decrements in forced expiratory volume in 1 second (FEV1), maximal mid-expiratory flow rate (FEF25-75), and forced expiratory flow rate at 75% of forced vital capacity (FEF75), and an increase in plasma clara cell protein (CC16) level. Changes in CC16 and lower respiratory symptoms, but not in lung function, were positively correlated with lifetime cumulative O3 exposure. Higher lifetime cumulative O3 exposure was associated with airway injury and respiratory symptom responses, but not with airway inflammatory or lung function responses, to acute O3 exposure.

  2. Developmental Effects of Lead Exposure in Children.

    ERIC Educational Resources Information Center

    Tesman, Johanna Rich; Hills, Amanda

    1994-01-01

    This report presents an overview of research on childhood lead exposure and poisoning, and the related social issues. The report first summarizes the history of lead poisoning and its prevalence in the United States, and discusses the basis for recent changes in guidelines for lead exposure by the Centers for Disease Control (CDC). The report then…

  3. Cumulant generating function formula of heat transfer in ballistic systems with lead-lead coupling and general nonlinear systems

    NASA Astrophysics Data System (ADS)

    Li, Huanan

    2013-03-01

    Based on a two-time observation protocol, we consider heat transfer in a given time interval tM in a lead-junction-lead system taking coupling between the leads into account. In view of the two-time observation, consistency conditions are carefully verified in our specific family of quantum histories. Furthermore, its implication is briefly explored. Then using the nonequilibrium Green's function method, we obtain an exact formula for the cumulant generating function for heat transfer between the two leads, valid in both transient and steady-state regimes. Also, a compact formula for the cumulant generating function in the long-time limit is derived, for which the Gallavotti-Cohen fluctuation symmetry is explicitly verified. In addition, we briefly discuss Di Ventra's repartitioning trick regarding whether the repartitioning procedure of the total Hamiltonian affects the nonequilibrium steady-state current fluctuation. All kinds of properties of nonequilibrium current fluctuations, such as the fluctuation theorem in different time regimes, could be readily given according to these exact formulas. Finally a practical formalism dealing with cumulants of heat transfer across general nonlinear quantum systems is established based on field theoretical/algebraic method.

  4. The EPA's human exposure research program for assessing cumulative risk in communities

    PubMed Central

    Zartarian, Valerie G; Schultz, Bradley D

    2009-01-01

    Communities are faced with challenges in identifying and prioritizing environmental issues, taking actions to reduce their exposures, and determining their effectiveness for reducing human health risks. Additional challenges include determining what scientific tools are available and most relevant, and understanding how to use those tools; given these barriers, community groups tend to rely more on risk perception than science. The U.S. Environmental Protection Agency's Office of Research and Development, National Exposure Research Laboratory (NERL) and collaborators are developing and applying tools (models, data, methods) for enhancing cumulative risk assessments. The NERL's “Cumulative Communities Research Program” focuses on key science questions: (1) How to systematically identify and prioritize key chemical stressors within a given community?; (2) How to develop estimates of exposure to multiple stressors for individuals in epidemiologic studies?; and (3) What tools can be used to assess community-level distributions of exposures for the development and evaluation of the effectiveness of risk reduction strategies? This paper provides community partners and scientific researchers with an understanding of the NERL research program and other efforts to address cumulative community risks; and key research needs and opportunities. Some initial findings include the following: (1) Many useful tools exist for components of risk assessment, but need to be developed collaboratively with end users and made more comprehensive and user-friendly for practical application; (2) Tools for quantifying cumulative risks and impact of community risk reduction activities are also needed; (3) More data are needed to assess community- and individual-level exposures, and to link exposure-related information with health effects; and (4) Additional research is needed to incorporate risk-modifying factors (“non-chemical stressors”) into cumulative risk assessments. The products

  5. Chronic lead exposure in children living in Miskolc Hungary, on the basis of teeth lead levels

    SciTech Connect

    Selypes, A.; Banfalvi, S.; Bokros, F.

    1997-03-01

    The lead pollution of the environment is a global problem. The major part of lead pollution can derive from the traffic, from exhausted gases of vehicles. Adverse health effects of lead exposure in childhood are well documented. Blood lead (Pb) levels are indicis of absorption during the previous 21- 30 days, whereas measurements of Pb in bone and in teeth reflect cumulative lead exposure. On the basis of that knowledge, we wanted to determine the tooth lead levels of children living in Miskolc, Hungary. The city of Miskolc is situated on the North-East part of Hungary, and can be characterized by urban-industrial air pollution. The population of the city is about 200,000. 10 refs., 1 fig., 3 tabs.

  6. The cumulative MeHg and PCBs exposure and risk of tribal ...

    EPA Pesticide Factsheets

    Studies have shown that the U.S. population continues to be exposed to methyl mercury (MeHg) and polychlorinated biphenyls (PCBs) due to the long half-life of those environmental contaminants. Fish intake of Tribal populations is much higher than the U.S. general population due to dietary habits and unique cultural practices. Large fish tissue concentration data sets from the Environmental Protections Agency’s (EPA’s) Office of Water, USGS’s EMMMA program, and other data sources, were integrated, analyzed, and combined with recent tribal fish intake data for exposure analyses using the dietary module within EPA’s SHEDS-Multimedia model. SHEDS-Multimedia is a physically-based, probabilistic model, which can simulate cumulative (multiple chemicals) or aggregate (single chemical) exposures over time for a population via various pathways of exposure for a variety of multimedia, multipathway environmental chemicals. Our results show that MeHg and total PCBs exposure of tribal populations from fish are about 3 to 10 and 5 to 15 times higher than the US general population, respectively, and that the estimated exposures pose potential health risks. The cumulative exposures of MeHg and total PCBs will be assessed to generate the joint exposure profiles for Tribal and US general populations. Model sensitivity analyses will identify the important contributions of the cumulative exposures of MeHg and total PCBs such as fish types, locations, and size, and key expos

  7. Fetal lead exposure: antenatal factors

    SciTech Connect

    Ernhart, C.B.; Wolf, A.W.; Sokol, R.J.; Brittenham, G.M.; Erhard, P.

    1985-10-01

    It was hypothesized that maternal blood lead level at delivery and cord blood lead level of the neonate would be affected by maternal use of alcohol, history of alcohol abuse, and smoking. The possibility that iron status, as reflected in maternal serum ferritin, would be related to lead level was also explored. The maternal history of alcohol abuse was unrelated to lead level in 208 samples of maternal blood and 178 samples of cord blood. However, alcohol use during pregnancy was related in a dose-response fashion to maternal and to cord blood lead level. This effect was significant with and without control of maternal smoking. The effect of maternal smoking and serum thiocyanate on maternal and cord blood lead level were also highly significant with and without control of the maternal drinking variable. Serum ferritin was marginally related to lead level for white women and for black infants, but tests of the dichotomized maternal ferritin variable did not yield a significant linkage with maternal or cord blood lead level. The results further support recommendations that women abstain from alcohol consumption and cigarette smoking in pregnancy.

  8. Cumulative violence exposure, emotional nonacceptance, and mental health symptoms in a community sample of women.

    PubMed

    Sundermann, Jane M; Chu, Ann T; DePrince, Anne P

    2013-01-01

    Women exposed to more types of violence (e.g., emotional, physical, or sexual violence)--referred to here as cumulative violence exposure--are at risk for more severe mental health symptoms compared to women who are exposed to a single type of violence or no violence. Women exposed to violence may also experience greater emotional nonacceptance compared to women with no exposure to violence. Emotional nonacceptance refers to an unwillingness to experience emotional states, including cognitive and behavioral attempts to avoid experiences of emotion. Given the links between cumulative violence exposure, emotional nonacceptance, and mental health symptoms among female victims of violence, the current study tested victims' emotional nonacceptance as a partial mediator between cumulative violence exposure and the severity of 3 types of symptoms central to complex trauma responses: depression, dissociation, and posttraumatic stress disorder (PTSD) symptoms. A non-treatment-seeking community sample of women (N = 89; M age = 30.70 years) completed self-report questionnaires and interviews. Bootstrap procedures were then used to test 3 mediation models for the separate predictions of depression, dissociation, and PTSD symptoms. Results supported our hypotheses that emotional nonacceptance would mediate the relationship between women's cumulative violence exposure and severity for all symptom types. The current findings highlight the role that emotional nonacceptance may play in the development of mental health symptoms for chronically victimized women and point to the need for longitudinal research in such populations.

  9. Association between Prenatal Lead Exposure and Blood Pressure in Children

    PubMed Central

    Zhang, Aimin; Sánchez, Brisa N.; Ettinger, Adrienne S.; Park, Sung Kyun; Cantonwine, David; Schnaas, Lourdes; Wright, Robert O.; Lamadrid-Figueroa, Hector; Tellez-Rojo, Martha Maria

    2011-01-01

    Background: Lead exposure in adults is associated with hypertension. Altered prenatal nutrition is associated with subsequent risks of adult hypertension, but little is known about whether prenatal exposure to toxicants, such as lead, may also confer such risks. Objectives: We investigated the relationship of prenatal lead exposure and blood pressure (BP) in 7- to 15-year-old boys and girls. Methods: We evaluated 457 mother–child pairs, originally recruited for an environmental birth cohort study between 1994 and 2003 in Mexico City, at a follow-up visit in 2008–2010. Prenatal lead exposure was assessed by measurement of maternal tibia and patella lead using in vivo K-shell X-ray fluorescence and cord blood lead using atomic absorption spectrometry. BP was measured by mercury sphygmomanometer with appropriate-size cuffs. Results: Adjusting for relevant covariates, maternal tibia lead was significantly associated with increases in systolic BP (SBP) and diastolic BP (DBP) in girls but not in boys (p-interaction with sex = 0.025 and 0.007 for SBP and DBP, respectively). Among girls, an interquartile range increase in tibia lead (13 μg/g) was associated with 2.11-mmHg [95% confidence interval (CI): 0.69, 3.52] and 1.60-mmHg (95% CI: 0.28, 2.91) increases in SBP and DBP, respectively. Neither patella nor cord lead was associated with child BP. Conclusions: Maternal tibia lead, which reflects cumulative environmental lead exposure and a source of exposure to the fetus, is a predisposing factor to higher BP in girls but not boys. Sex-specific adaptive responses to lead toxicity during early-life development may explain these differences. PMID:21947582

  10. Lead Exposure Hazard Management Guide

    DTIC Science & Technology

    1993-12-01

    one of the most common and preventable pediatric health problems in the United States today. Children are particularly susceptible to lead’s toxic...that have large percentages of children without lead poisoning problems can suspend the universal screening PROGRAM by submitting a letter of request, to...be frequented/used by children under the age of seven. Air Force Policy prioritizes specific facilities as follows: child development centers, annexes

  11. Relationship between prenatal lead exposure and infant blood lead levels.

    PubMed

    Archer, Natalie P; Bradford, Carrie M; Klein, David M; Barnes, Jim; Smith, L J; Villanacci, John F

    2012-10-01

    Recent literature has shown that analyzing newborn dried blood spots (DBS) may be effective in assessing some prenatal environmental exposures, such as exposure to lead. The purpose of this study was to evaluate the relationship between prenatal exposure to lead (as measured by newborn DBS results) and blood lead levels (BLLs) in infants 6 months of age or younger, using public health registry data for infants born in Texas from July 2002 through July 2006. The Texas Child Lead Registry (TCLR) was used to identify infants with documented elevated BLLs of 10 μg/dL or higher as well as infants with documented low BLLs. BLLs for these children were compared to their corresponding newborn DBS results using Pearson correlation coefficients and exact logistic regression models. Overall, a significant but weak positive correlation was found between infant BLLs and corresponding newborn DBS lead levels (r = 0.48). However, the odds of an infant with an elevated newborn DBS lead level having an elevated BLL at 6 months of age or younger were much greater than for an infant with a low newborn DBS lead level of <5 μg/dL (adjusted odds ratio 27.95, 95% CI: 5.52-277.28). Although an association was observed between newborn DBS lead levels and BLLs in infants tested between 0 to 6 months of age, our findings suggest that prenatal exposure may not be the only significant source of lead exposure for infants ≤6 months of age.

  12. Maternal lead exposure and the secondary sex ratio.

    PubMed

    Jarrell, John F; Weisskopf, Marc G; Weuve, Jennifer; Téllez-Rojo, Maria Martha; Hu, Howard; Hernández-Avila, Mauricio

    2006-07-01

    A reduction in the secondary sex ratio may be associated with exposure to environmental toxicants. Little data exists relating this outcome to lead exposure, a well-known reproductive toxicant. We studied 1980 women having singleton births from 1994 to 1995 and from 1997 to 2001 who participated in a cohort study of lead exposure and infant outcomes in Mexico City. Levels of lead were measured in maternal and cord blood using graphite furnace atomic absorption spectroscopy, and levels of lead in maternal patella and tibia bone (a reflection of cumulative exposure) were measured using noninvasive K-X-ray fluorescence measurements. Using logistic regression models, we evaluated the relations of these measures to secondary sex ratio in the offspring, adjusting for maternal age, parity and year of infants' birth. We found no consistent association between any of the lead measures and secondary sex ratio. Results were unchanged when we adjusted for infants' year of birth, maternal age and parity. Despite a large sample size and the use of sensitive biomarkers, we did not find evidence that maternal and fetal lead exposure is associated with a lower secondary sex ratio among newborns.

  13. Environmental lead exposure and the kidney

    SciTech Connect

    Bernard, B.P.; Becker, C.E.

    1988-01-01

    Lead and its components remain widely distributed in the environment and in some workplaces. Lead serves no useful physiological function, yet is potentially toxic to several organ systems. For many years human health effects have been recognized after heavy lead exposure. Recently more subtle human effects have been suggested invoking nervous system, reproductive and kidney function. Assessing lead body burden and dose-response relationships of this metal by blood lead determination, porphyrin assessments, chelation testing or bone lead studies may be difficult. Quantitative assessment of subtle changes in kidney function by routine BUN, creatinine, or urinalysis also poses problems. There is now mounting evidence that chronic low level environmental lead exposure may subtly effect kidney function. This paper first examines the history of lead and kidney function and then examines critically the evidence associating low-level environmental lead exposure and effects on renal function. 119 references.

  14. USING DOSE ADDITION TO ESTIMATE CUMULATIVE RISKS FROM EXPOSURES TO MULTIPLE CHEMICALS

    EPA Science Inventory

    The Food Quality Protection Act (FQPA) of 1996 requires the EPA to consider the cumulative risk from exposure to multiple chemicals that have a common mechanism of toxicity. Three methods, hazard index (HI), point-of-departure index (PODI), and toxicity equivalence factor (TEF), ...

  15. Cumulative Effects of Exposure to Violence on Posttraumatic Stress in Palestinian and Israeli Youth

    ERIC Educational Resources Information Center

    Dubow, Eric F.; Boxer, Paul; Huesmann, L. Rowell; Landau, Simha; Dvir, Shira; Shikaki, Khalil; Ginges, Jeremy

    2012-01-01

    We examine cumulative and prospective effects of exposure to conflict and violence across four contexts (ethnic-political, community, family, school) on posttraumatic stress (PTS) symptoms in Palestinian and Israeli youth. Interviews were conducted with 600 Palestinian and 901 Israeli (Jewish and Arab) children (ages 8, 11, and 14) and their…

  16. USING DOSE ADDITION TO ESTIMATE CUMULATIVE RISKS FROM EXPOSURES TO MULTIPLE CHEMICALS

    EPA Science Inventory

    The Food Quality Protection Act (FQPA) of 1996 requires the EPA to consider the cumulative risk from exposure to multiple chemicals that have a common mechanism of toxicity. Three methods, hazard index (HI), point-of-departure index (PODI), and toxicity equivalence factor (TEF), ...

  17. HEALTH AND ENVIRONMENTAL SCIENCES INSTITUTE'S EXPOSURE FACTORS DATABASE FOR AGGREGATE AND CUMULATIVE RISK ASSESSMENT

    EPA Science Inventory

    In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of input...

  18. Cumulative Effects of Exposure to Violence on Posttraumatic Stress in Palestinian and Israeli Youth

    ERIC Educational Resources Information Center

    Dubow, Eric F.; Boxer, Paul; Huesmann, L. Rowell; Landau, Simha; Dvir, Shira; Shikaki, Khalil; Ginges, Jeremy

    2012-01-01

    We examine cumulative and prospective effects of exposure to conflict and violence across four contexts (ethnic-political, community, family, school) on posttraumatic stress (PTS) symptoms in Palestinian and Israeli youth. Interviews were conducted with 600 Palestinian and 901 Israeli (Jewish and Arab) children (ages 8, 11, and 14) and their…

  19. HEALTH AND ENVIRONMENTAL SCIENCES INSTITUTE'S EXPOSURE FACTORS DATABASE FOR AGGREGATE AND CUMULATIVE RISK ASSESSMENT

    EPA Science Inventory

    In recent years, the risk analysis community has broadened its use of complex aggregate and cumulative residential exposure models (e.g., to meet the requirements of the 1996 Food Quality Protection Act). The value of these models is their ability to incorporate a range of input...

  20. Is Cumulated Pyrethroid Exposure Associated With Prediabetes? A Cross-sectional Study

    PubMed Central

    Hansen, Martin Rune; Jørs, Erik; Lander, Flemming; Condarco, Guido; Schlünssen, Vivi

    2014-01-01

    ABSTRACT Pyrethroids are a class of insecticides used widely for vector control programs. Acute pyrethroid poisoning is rare, but well documented, whereas effects of cumulative exposure are insufficiently described, including possible negative effect on glucose regulation. The objective of this study was to investigate an association between exposure to pyrethroids and abnormal glucose regulation (prediabetes or diabetes). A cross-sectional study was performed among 116 pesticide sprayers from public vector control programs in Bolivia and 92 nonexposed controls. Pesticide exposure (duration, intensity, cumulative exposure) was assessed from questionnaire data. Participants were asked about symptoms of diabetes. Blood samples were analyzed for glycosylated hemoglobin (HbA1c), a measure of glucose regulation. No association was found between pyrethroid exposure and diabetes symptoms. The prevalence of abnormal glucose regulation (defined as HbA1c ≥ 5.6%) was 61.1% among sprayers and 7.9% among nonexposed controls, corresponding to an adjusted odds ratio (OR [95% confidence interval]) for all sprayers of 11.8 [4.2–33.2] and 18.5 [5.5–62.5] for pyrethroid-exposed only. Among sprayers who had only used pyrethroids, a significant positive trend was observed between cumulative pesticide exposure (total number of hours sprayed) and adjusted OR of abnormal glucose regulation, with OR 14.7 [0.9–235] in the third exposure quintile. The study found a severely increased prevalence of prediabetes among Bolivian pesticide sprayers compared with a control group, but the relevance of the control group is critical. Within the spraying group, an association between cumulative exposure to pyrethroids and abnormal glucose regulation was seen. Further studies are needed to confirm this association. PMID:25275407

  1. Cumulative exposure to dust causes accelerated decline in lung function in tunnel workers

    PubMed Central

    Ulvestad, B; Bakke, B; Eduard, W; Kongerud, J; Lund, M

    2001-01-01

    OBJECTIVES—To examine whether underground construction workers exposed to tunnelling pollutants over a follow up period of 8 years have an increased risk of decline in lung function and respiratory symptoms compared with reference subjects working outside the tunnel atmosphere, and relate the findings to job groups and cumulative exposure to dust and gases.
METHODS—96 Tunnel workers and a reference group of 249 other heavy construction workers were examined in 1991 and re-examined in 1999. Exposure measurements were carried out to estimate personal cumulative exposure to total dust, respirable dust, α-quartz, oil mist, and nitrogen dioxide. The subjects answered a questionnaire on respiratory symptoms and smoking habits, performed spirometry, and had chest radiographs taken. Radiological signs of silicosis were evaluated (International Labour Organisation (ILO) classification). Atopy was determined by a multiple radioallergosorbent test (RAST).
RESULTS—The mean exposure to respirable dust and α-quartz in tunnel workers varied from 1.2-3.6 mg/m3 (respirable dust) and 0.019-0.044 mg/m3 (α-quartz) depending on job task performed. Decrease in forced expiratory volume in 1 second (FEV1) was associated with cumulative exposure to respirable dust (p<0.001) and α-quartz (p=0.02). The multiple regression model predicted that in a worker 40 years of age, the annual decrease in FEV1 would be 25 ml in a non-exposed non-smoker, 35 ml in a non-exposed smoker, and 50-63 ml in a non-smoking tunnel worker (depending on job). Compared with the reference group the odds ratio for the occurrence of new respiratory symptoms during the follow up period was increased in the tunnel workers and associated with cumulative exposure to respirable dust.
CONCLUSIONS—Cumulative exposures to respirable dust and α-quartz are the most important risk factors for airflow limitation in underground heavy construction workers, and cumulative exposure to respirable dust is the

  2. Cumulative exposure to poor housing affordability and its association with mental health in men and women.

    PubMed

    Bentley, Rebecca; Baker, Emma; Mason, Kate

    2012-09-01

    Poor housing affordability affects around 10% of the Australian population and is increasingly prevalent. The authors tested two hypotheses: that cumulative exposure to housing affordability stress (HAS) is associated with poorer mental health and that effects vary by gender. The authors estimated the relationship between cumulative exposure to HAS and mental health among 15478 participants in an Australian longitudinal survey between 2001 and 2009. Individuals were classified as being in HAS if household income was in the lowest 40% of the national distribution and housing costs exceeded 30% of income. Exposure to HAS ranged from 1 to 8 annual waves. Mental health was measured using the Short Form 36 Mental Component Summary (MCS) score. To test the extent to which any observed associations were explained by compositional factors, random- and fixed-effects models were estimated. In the random-effects models, mental health scores decreased with increasing cumulative exposure to HAS (up until 4+ years). This relationship differed by gender, with a stronger dose-response observed among men. The mean MCS score of men experiencing four to eight waves of housing stress was 2.02 points lower than men not in HAS (95% CI -3.89 to -0.16). In the fixed-effects models, there was no evidence of a cumulative effect of HAS on mental health; however, lower MCS was observed after a single year in HAS (β=-0.70, 95% CI -1.02 to -0.37). While average mental health was lower for individuals with longer exposure to HAS, the mental health effect appears to be due to compositional factors. Furthermore, men and women appear to experience cumulative HAS differently.

  3. Lead absorption in cows: biological indicators of ambient lead exposure

    SciTech Connect

    Karacic, V.; Prpic-Majic, D.; Skender, L.

    1984-03-01

    In order to determine actual lead exposure from residual amounts of lead in the environmental soil following the introduction of effective engineering emission controls in a lead smeltery, the absorption of lead in cows grazing in the vicinity was investigated. Four groups of cows were examined: two groups of cows exposed to different ambient lead concentration, compared with two normal groups of cows. In each cow aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin (EP) and blood lead (Pb-B) were determined, two years prior to and four years after the technical sanitation of the lead emission source. The results demonstrated normalization of ALAD, EP and Pb-B after the technical sanitation. In spite of normalization, biological indicators ALAD and Pb-B determined four years after the technical sanitation showed increased lead absorption in comparison with the results of the control group. This indirectly indicates lead contamination of the environment from residual amounts of lead in the soil.

  4. Overview of radon, lead and asbestos exposure

    SciTech Connect

    Demers, R. )

    1991-11-01

    Reducing the incidence of diseases caused by exposure to radon, lead and asbestos is a major public health challenge. Radon gas, which usually enters a home through the foundation, can cause lung cancer. Exposure to lead through paint, auto emissions and other sources can cause neurologic deficits, as well as anemia, abnormal vitamin D metabolism, nephropathy, hypertension and reproductive abnormalities. Asbestos, which is used in a vast number of products, is primarily associated with parenchymal asbestosis, pleural fibrosis, mesothelioma and lung cancer. The family physician can play a pivotal role in providing information about hazardous exposure, sources of exposure, epidemiology and disease prevention.29 references.

  5. Cumulative exposure to dust and gases as determinants of lung function decline in tunnel construction workers

    PubMed Central

    Bakke, B; Ulvestad, B; Stewart, P; Eduard, W

    2004-01-01

    Aims: To study the relation between lung function decrease and cumulative exposure to dust and gases in tunnel construction workers. Methods: A total of 651 male construction workers (drill and blast workers, tunnel concrete workers, shotcreting operators, and tunnel boring machine workers) were followed up by spirometric measurements in 1989–2002 for an average of six years. Outdoor concrete workers, foremen, and engineers served as a low exposed referent population. Results: The between worker component of variability was considerably reduced within the job groups compared to the whole population, suggesting that the workers within job groups had similar exposure levels. The annual decrease in FEV1 in low-exposed non-smoking workers was 21 ml and 24 ml in low-exposed ever smokers. The annual decrease in FEV1 in tunnel construction workers was 20–31 ml higher than the low exposed workers depending on job group for both non-smokers and ever smokers. After adjustment for age and observation time, cumulative exposure to nitrogen dioxide showed the strongest association with a decrease in FEV1 in both non-smokers, and ever smokers. Conclusion: Cumulative exposure to nitrogen dioxide appeared to be a major risk factor for lung function decreases in these tunnel construction workers, although other agents may have contributed to the observed effect. Contact with blasting fumes should be avoided, diesel exhaust emissions should be reduced, and respiratory devices should be used to protect workers against dust and nitrogen dioxide exposure. PMID:14985522

  6. DIETARY EXPOSURE OF CHILDREN TO LEAD

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because 1) they have more opportunity for contact with lead sources due to their activities, 2) lead adsorption occurs more readily in a child as compared to an adult, and 3) the child's development is more vulnerable ...

  7. DIETARY EXPOSURE OF CHILDREN TO LEAD

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because 1) they have more opportunity for contact with lead sources due to their activities, 2) lead adsorption occurs more readily in a child as compared to an adult, and 3) the child's development is more vulnerable ...

  8. Case-control study of cumulative cigarette tar exposure and lung and upper aerodigestive tract cancers.

    PubMed

    Meyers, Travis J; Chang, Shen-Chih; Chang, Po-Yin; Morgenstern, Hal; Tashkin, Donald P; Rao, Jian-Yu; Cozen, Wendy; Mack, Thomas M; Zhang, Zuo-Feng

    2017-05-01

    The development of comprehensive measures for tobacco exposure is crucial to specify effects on disease and inform public health policy. In this population-based case-control study, we evaluated the associations between cumulative lifetime cigarette tar exposure and cancers of the lung and upper aerodigestive tract (UADT). The study included 611 incident cases of lung cancer; 601 cases of UADT cancers (oropharyngeal, laryngeal and esophageal cancers); and 1,040 cancer-free controls. We estimated lifetime exposure to cigarette tar based on tar concentrations abstracted from government cigarette records and self-reported smoking histories derived from a standardized questionnaire. We analyzed the associations for cumulative tar exposure with lung and UADT cancer, overall and according to histological subtype. Cumulative tar exposure was highly correlated with pack-years among ever smoking controls (Pearson coefficient = 0.90). The adjusted odds ratio (95% confidence limits) for the estimated effect of about 1 kg increase in tar exposure (approximately the interquartile range in all controls) was 1.61 (1.50, 1.73) for lung cancer and 1.21 (1.13, 1.29) for UADT cancers. In general, tar exposure was more highly associated with small, squamous and large cell lung cancer than adenocarcinoma. With additional adjustment for pack-years, positive associations between tar and lung cancer were evident, particularly for small cell and large cell subtypes. Therefore, incorporating the composition of tobacco carcinogens in lifetime smoking exposure may improve lung cancer risk estimation. This study does not support the claim of a null or inverse association between "low exposure" to tobacco smoke and risk of these cancer types.

  9. Aggregate Exposure and Cumulative Risk Assessment--Integrating Occupational and Non-occupational Risk Factors.

    PubMed

    Lentz, T J; Dotson, G S; Williams, P R D; Maier, A; Gadagbui, B; Pandalai, S P; Lamba, A; Hearl, F; Mumtaz, M

    2015-01-01

    Occupational exposure limits have traditionally focused on preventing morbidity and mortality arising from inhalation exposures to individual chemical stressors in the workplace. While central to occupational risk assessment, occupational exposure limits have limited application as a refined disease prevention tool because they do not account for all of the complexities of the work and non-occupational environments and are based on varying health endpoints. To be of greater utility, occupational exposure limits and other risk management tools could integrate broader consideration of risks from multiple exposure pathways and routes (aggregate risk) as well as the combined risk from exposure to both chemical and non-chemical stressors, within and beyond the workplace, including the possibility that such exposures may cause interactions or modify the toxic effects observed (cumulative risk). Although still at a rudimentary stage in many cases, a variety of methods and tools have been developed or are being used in allied risk assessment fields to incorporate such considerations in the risk assessment process. These approaches, which are collectively referred to as cumulative risk assessment, have potential to be adapted or modified for occupational scenarios and provide a tangible path forward for occupational risk assessment. Accounting for complex exposures in the workplace and the broader risks faced by the individual also requires a more complete consideration of the composite effects of occupational and non-occupational risk factors to fully assess and manage worker health problems. Barriers to integrating these different factors remain, but new and ongoing community-based and worker health-related initiatives may provide mechanisms for identifying and integrating risk from aggregate exposures and cumulative risks from all relevant sources, be they occupational or non-occupational.

  10. Aggregate Exposure and Cumulative Risk Assessment—Integrating Occupational and Non-occupational Risk Factors

    PubMed Central

    Lentz, T. J.; Dotson, G. S.; Williams, P. R.D.; Maier, A.; Gadagbui, B.; Pandalai, S. P.; Lamba, A.; Hearl, F.; Mumtaz, M.

    2015-01-01

    Occupational exposure limits have traditionally focused on preventing morbidity and mortality arising from inhalation exposures to individual chemical stressors in the workplace. While central to occupational risk assessment, occupational exposure limits have limited application as a refined disease prevention tool because they do not account for all of the complexities of the work and non-occupational environments and are based on varying health endpoints. To be of greater utility, occupational exposure limits and other risk management tools could integrate broader consideration of risks from multiple exposure pathways and routes (aggregate risk) as well as the combined risk from exposure to both chemical and non-chemical stressors, within and beyond the workplace, including the possibility that such exposures may cause interactions or modify the toxic effects observed (cumulative risk). Although still at a rudimentary stage in many cases, a variety of methods and tools have been developed or are being used in allied risk assessment fields to incorporate such considerations in the risk assessment process. These approaches, which are collectively referred to as cumulative risk assessment, have potential to be adapted or modified for occupational scenarios and provide a tangible path forward for occupational risk assessment. Accounting for complex exposures in the workplace and the broader risks faced by the individual also requires a more complete consideration of the composite effects of occupational and non-occupational risk factors to fully assess and manage worker health problems. Barriers to integrating these different factors remain, but new and ongoing community-based and worker health-related initiatives may provide mechanisms for identifying and integrating risk from aggregate exposures and cumulative risks from all relevant sources, be they occupational or non-occupational. PMID:26583907

  11. DOSE-RESPONSE MODELING FOR THE ASSESSMENT OF CUMULATIVE RISK DUE TO EXPOSURE TO N-METHYL CARBAMATE PESTICIDES

    EPA Science Inventory

    The US EPAs N-Methyl Carbamate Cumulative Risk Assessment (NMCRA) assesses the effect on acetylcholine esterase (AChE) activity of exposure to 10 N-methyl carbamate (NMC) pesticides through dietary, drinking water, and residential exposures.

  12. High lead exposure in two leaded bronze ingot foundry workers.

    PubMed

    Song, Yoojun; Suh, Chunhui; Kim, Shin-Ae; Kim, Nami; Kim, Sung-Min; Jeong, Seong-Wook; Kim, Se-Yeong; Kim, Kun-Hyung; Kim, Jeong-Ho; Son, Byung-Chul; Lee, Chae-Kwan; Lee, Jong-Tae

    2014-01-01

    Awareness about lead poisoning in South Korea has increased; however, occupational exposures occurring in small-scale businesses have not been thoroughly investigated. We report two cases of high lead exposure in a leaded bronze ingot foundry. Two employees, a 54-year-old primary operator and a 46-year-old assistant, at a small-scale metalworking company who had been employed for 18 years and 1 month, respectively, showed elevated blood lead levels (61.1 μg/dL and 51.7 μg/dL, respectively) at an occupational health checkup. Neither worker complained of abnormal symptoms nor signs related to lead poisoning. Health assessment follow-ups were conducted and biological exposure indices of lead were calculated every four weeks. After the initial follow-up assessment, both workers were relocated from the foundry process to the metalworking process. In addition, a localized exhaust system was installed after the second follow-up. Foundry workers in a small-scale businesses might be at high risk of lead exposure because these businesses might be vulnerable to poor industrial hygiene. Therefore, regular occupational health checkups are required.

  13. Blood pressure and industrial lead exposure.

    PubMed

    Maheswaran, R; Gill, J S; Beevers, D G

    1993-03-15

    The association between environmental lead exposure and raised blood pressure remains controversial. This association was examined in a cross-sectional study in 1981 on 809 male workers who were occupationally exposed to lead in a factory manufacturing car lead accumulator batteries in Birmingham, United Kingdom. Lead exposure was assessed by blood lead levels, blood zinc protoporphyrin levels, and years of industrial exposure to lead. The geometric mean blood lead level was 31.6 micrograms/dl with minimum and maximum values of 0 microgram/dl and 98 micrograms/dl, respectively. Unadjusted systolic blood pressure rose with increasing blood lead levels (analysis of variance, F = 3.3, p < 0.05) from 127 mmHg (95% confidence interval (CI) 123.5-130.5) in men with blood lead levels less than 21 micrograms/dl to 133 mmHg (95% CI 128.7-137.3) in men with levels exceeding 50 micrograms/dl. Following adjustment for the confounding effects of age, body mass index, and alcohol consumption, however, the effect of blood lead on systolic pressure was diminished (analysis of variance, F = 1.3, not significant) to 129 mmHg and 132 mmHg in the respective categories. There was no association between diastolic blood pressure and blood lead. Zinc protoporphyrin levels and years of industrial lead exposure did not raise adjusted systolic or diastolic pressure. In conclusion, subject to the limitations inherent in a cross-sectional survey, the findings are consistent with a weak effect of industrial lead exposure on systolic blood pressure, within the range of exposures observed in this study.

  14. Tenofovir, Emtricitabine, and Tenofovir Diphosphate in Dried Blood Spots for Determining Recent and Cumulative Drug Exposure

    PubMed Central

    Castillo-Mancilla, Jose R.; Zheng, Jia-Hua; Rower, Joseph E.; Meditz, Amie; Gardner, Edward M.; Predhomme, Julie; Fernandez, Caitlin; Langness, Jacob; Kiser, Jennifer J.; Bushman, Lane R.

    2013-01-01

    Abstract Tenofovir (TFV) disoproxil fumarate (TDF)±emtricitabine (FTC) are widely used for HIV treatment and chemoprophylaxis, but variable adherence may lead to suboptimal responses. Methods that quantify adherence would allow for interventions to improve treatment and prevention outcomes. Our objective was to characterize the pharmacokinetics of TFV-diphosphate (TFV-DP) and FTC-triphosphate (FTC-TP) in red blood cells (RBCs) and peripheral blood mononuclear cells (PBMCs); to extend the RBC analysis to dried blood spots (DBSs); and to model how RBC/DBS monitoring could inform recent and cumulative drug exposure/adherence. Blood samples were collected from 17 HIV-negative adults at 5 visits over a 30-day pharmacokinetics study of daily oral TDF/FTC. Dosing was discontinued on day 30 and blood was collected on days 35, 45, and 60 during the washout period. Plasma/RBCs/PBMCs/DBSs were all quantified by liquid chromatography/tandem mass spectrometry. DBSs were paired with RBCs and plasma for comparisons. The median (interquartile range) RBC TFV-DP half-life was 17.1 (15.7–20.2) versus 4.2 (3.7–5.2) days in PBMCs. At steady state, TFV-DP was 130 fmol/106 RBCs versus 98 fmol/106 PBMCs. FTC-TP was not quantifiable in most RBC samples. TFV-DP in RBCs versus DBSs yielded an r2=0.83. TFV-DP in DBSs was stable at −20°C. Simulations of TFV-DP in RBCs/DBSs, when dosed from one to seven times per week, demonstrated that each dose per week resulted in an average change of approximately 19 fmol/106 RBCs and 230 fmol/punch. TFV and FTC in plasma versus DBSs was defined by y=1.4x; r2=0.96 and y=0.8x; r2=0.99, respectively. We conclude that DBSs offer a convenient measure of recent (TFV/FTC) and cumulative (TFV-DP in RBCs) drug exposure with potential application to adherence monitoring. PMID:22935078

  15. Cumulative exposure to short sleep and body mass outcomes: a prospective study.

    PubMed

    Krueger, Patrick M; Reither, Eric N; Peppard, Paul E; Burger, Andrew E; Hale, Lauren

    2015-12-01

    Short sleep duration is associated with excess body mass among adolescents and young adults. The mechanisms theorized to drive that association suggest that persistent exposure to short sleep should be associated with greater accumulations of body mass. We use prospective cohort data from four waves of the National Longitudinal Study of Adolescent to Adult Health (1994-2009; n = 14 800) to examine associations between cumulative exposure to short sleep throughout adolescence and early adulthood and obesity and elevated waist circumference outcomes. We compare several clinical and distribution-based standards of short sleep to assess which measures are associated most strongly with body mass. Cumulative exposure to short sleep exhibits dose-response associations with obesity and elevated waist circumference. Relative to respondents with no instances of short sleep, those who slept -0.50 standard deviations or less than the age and sex-specific average sleep hours in all four waves had 1.45 [95% confidence interval (CI): 1.03, 2.04] times the odds of being obese and 1.45 (95% CI: 1.02, 2.06) times the odds of having an elevated waist circumference. Our findings suggest that cumulative exposure to short sleep during adolescence and young adulthood may play an important role in the etiology of obesity and elevated waist circumference during this important developmental period.

  16. Cumulative Exposure to Short Sleep and Body Mass Outcomes: A Prospective Study

    PubMed Central

    Krueger, Patrick M.; Reither, Eric N.; Peppard, Paul E.; Burger, Andrew E.; Hale, Lauren

    2016-01-01

    SUMMARY Short sleep duration is associated with excess body mass among adolescents and young adults. The mechanisms theorized to drive that association suggest that persistent exposure to short sleep should be associated with greater accumulations of body mass. We use prospective cohort data from four waves of the National Longitudinal Study of Adolescent to Adult Health (1994–2009; N=14,800) to examine associations between cumulative exposure to short sleep throughout adolescence and early adulthood, and obesity and elevated waist circumference outcomes. We compare several clinical and distribution-based standards of short sleep to assess which measures are most strongly associated with body mass. Cumulative exposure to short sleep exhibits dose-response associations with obesity and elevated waist circumference. Relative to respondents with no instances of short sleep, those who slept −0.50 standard deviations or less than the age and sex-specific average sleep hours in all four waves had 1.45 (95% CI=1.03, 2.04) times the odds of being obese and 1.45 (95% CI=1.02, 2.06) times the odds of having an elevated waist circumference. Our findings suggest that cumulative exposure to short sleep during adolescence and young adulthood may play an important role in the development of obesity and elevated waist circumference during this important developmental period. PMID:26211809

  17. Human biomonitoring issues related to lead exposure.

    PubMed

    Nieboer, Evert; Tsuji, Leonard J S; Martin, Ian D; Liberda, Eric N

    2013-10-01

    Lead as a toxic environmental metal has been an issue of concern for 30-40 years. Even though the exposures experienced by the general public have been significantly reduced, so have the acceptable blood lead concentrations assessed to safeguard health (specifically of children). The impact of these concurrent changes are reviewed and discussed in terms of the following: blood lead as the primary biomarker of exposure; pertinent toxicokinetic issues including modelling; legacy and newer sources of this toxic metal; improvements in lead quantification techniques and its characterization (chemical forms) in exposure media; and in vivo markers of lead sources. It is concluded that the progress in the quantification of lead and its characterization in exposure media have supported the efforts to identify statistical associations of lead in blood and tissues with adverse health outcomes, and have guided strategies to reduce human exposure (especially for children). To clarify the role of lead as a causative factor in disease, greater research efforts in biomarkers of effect and susceptibility seem timely.

  18. Occupational lead exposure and blood pressure.

    PubMed Central

    Parkinson, D K; Hodgson, M J; Bromet, E J; Dew, M A; Connell, M M

    1987-01-01

    Recent community studies have suggested that low level lead exposure is significantly associated with blood pressure in the general population. This finding is inconsistent with the results of recent occupational studies of lead exposed workers, although the occupational studies contained serious methodological weaknesses. The present study examined the relation between occupational lead exposure and diastolic and systolic blood pressure in randomly selected samples of 270 exposed and 158 non-exposed workers. Four exposure indicators were examined: employment at a lead battery plant nu a control plant, current blood lead value, current zinc protoporphyrin value, and time weighted average blood lead value. After controlling for other known risk factors such as age, education, income, cigarette usage, alcohol consumption, and exercise, the associations between exposure and blood pressure were small and non-significant. In the absence of a biologically feasible hypothesis regarding the mechanism by which low level lead exposure would influence blood pressure the present findings challenge the validity of the general population association. PMID:3689706

  19. Association of senile lens and dermal changes with cumulative ultraviolet exposure

    SciTech Connect

    Cameron, L.L.

    1986-01-01

    A cross-sectional prevalence survey of senile lens opacities was conducted, using as subjects white men between the ages of 40 and 70 years who had a biopsy of their facial skin within the previous 18 months. Specimens were graded by the extent of dermal elastosis seen histologically; this ordinal grading acted as a measure of cumulative solar UV exposure in this population. The men attended a clinic when they received an ophthalmic examination, including grading of the type and severity of senile lens opacity seen in each eye after mydriasis. A history of exposure to sun and other potential cataract risk factors was obtained by interview. The visual appearance of actinic damage to their facial skin was graded and recorded. The history of sun exposure was used to calculate a cumulative UVB exposure index; this index and the visual grading were tested as measures of solar UV damage against the histological elastosis grade. The three exposure measures were not found to be equivalent. The UVB exposure index was not a good predictor of either measure of skin damage after adjustment by age and susceptibility to sun damage, and may be confounded by behavioral practices which were not recorded. This visual assessment of actinic skin damage was a significant predictor of severe actinic elastosis, but also appears to be confounded by age, which was incompletely controlled by adjustment. In both cases, the best predictor of severe actinic elastosis was poor ability to tan, a measure of susceptibility to sun damage.

  20. Cumulative social risk exposure, infant birthweight, and cognitive delay in infancy

    PubMed Central

    Cheng, Erika R.; Poehlmann, Julie; Mullahy, John; Witt, Whitney P.

    2014-01-01

    Objective To determine: (1) the effect of exposure to multiple social risks on cognitive delay at nine-months of age; and (2) whether obstetric factors mediate the relationship between cumulative social risk and cognitive delay. Methods Data were from 8,950 mother-child dyads participating in the first wave of the Early Childhood Longitudinal Study, Birth Cohort. Cognitive delay was defined as falling in the lowest 10% of mental scale scores from the Bayley Short Form-Research Edition. Five social risk factors were combined and categorized into a “social risk index.” Staged multivariable logistic regressions were used to investigate whether obstetric factors mediated the impact of social risk on the odds of cognitive delay. Results Infants with cognitive delay were more likely to live with social risks than infants without cognitive delay. The percentage of infants with cognitive delay increased with the number of social risks. In adjusted analyses, exposure to multiple social risk factors was associated with higher odds of cognitive delay at nine-months of age (adjusted odds ratio 2.11; 95% confidence interval: 1.18-3.78 for four or more risks versus no risks). Accounting for birthweight attenuated this relationship (p<0.001). Conclusions This is the first population-based study to investigate the independent and cumulative effects of social risk factors on cognitive delay in infancy. Findings show a significant cumulative relationship between exposure to social risk and cognitive delay, which is partly mediated by birthweight. Programs that address the social context of US infants are needed to improve their developmental trajectories. What's New National data show a significant cumulative relationship between exposure to social risks and cognitive delay in infancy, which is mediated by infant birthweight. Programs that address the social context of US infants are needed to improve their developmental trajectories. PMID:25439156

  1. Toddler temperament and prenatal exposure to lead and maternal depression.

    PubMed

    Stroustrup, Annemarie; Hsu, Hsiao-Hsien; Svensson, Katherine; Schnaas, Lourdes; Cantoral, Alejandra; Solano González, Maritsa; Torres-Calapiz, Mariana; Amarasiriwardena, Chitra; Bellinger, David C; Coull, Brent A; Téllez-Rojo, Martha M; Wright, Robert O; Wright, Rosalind J

    2016-06-16

    Temperament is a psychological construct that reflects both personality and an infant's reaction to social stimuli. It can be assessed early in life and is stable over time Temperament predicts many later life behaviors and illnesses, including impulsivity, emotional regulation and obesity. Early life exposure to neurotoxicants often results in developmental deficits in attention, social function, and IQ, but environmental predictors of infant temperament are largely unknown. We propose that prenatal exposure to both chemical and non-chemical environmental toxicants impacts the development of temperament, which can itself be used as a marker of risk for maladaptive neurobehavior in later life. In this study, we assessed associations among prenatal and early life exposure to lead, mercury, poverty, maternal depression and toddler temperament. A prospective cohort of women living in the Mexico City area were followed longitudinally beginning in the second trimester of pregnancy. Prenatal exposure to lead (blood, bone), mercury, and maternal depression were assessed repeatedly and the Toddler Temperament Scale (TTS) was completed when the child was 24 months old. The association between each measure of prenatal exposure and performance on individual TTS subscales was evaluated by multivariable linear regression. Latent profile analysis was used to classify subjects by TTS performance. Multinomial regression models were used to estimate the prospective association between prenatal exposures and TTS performance. 500 mother-child pairs completed the TTS and had complete data on exposures and covariates. Three latent profiles were identified and categorized as predominantly difficult, intermediate, or easy temperament. Prenatal exposure to maternal depression predicted increasing probability of difficult toddler temperament. Maternal bone lead, a marker of cumulative exposure, also predicted difficult temperament. Prenatal lead exposure modified this association

  2. A quantitative approach to the characterization of cumulative and average solvent exposure in paint manufacturing plants.

    PubMed

    Ford, D P; Schwartz, B S; Powell, S; Nelson, T; Keller, L; Sides, S; Agnew, J; Bolla, K; Bleecker, M

    1991-06-01

    Previous reports have attributed a range of neurobehavioral effects to low-level, occupational solvent exposure. These studies have generally been limited in their exposure assessments and have specifically lacked good estimates of exposure intensity. In the present study, the authors describe the development of two exposure variables that quantitatively integrate industrial hygiene sampling data with estimates of exposure duration--a cumulative exposure (CE) estimate and a lifetime weighted average exposure (LWAE) estimate. Detailed occupational histories were obtained from 187 workers at two paint manufacturing plants. Historic industrial hygiene sampling data for total hydrocarbons (a composite variable of the major neurotoxic solvents present) were grouped according to 20 uniform, temporally stable exposure zones, which had been defined during plant walk-through surveys. Sampling at the time of the study was used to characterize the few zones for which historic data were limited or unavailable. For each participant, the geometric mean total hydrocarbon level for each exposure zone worked in was multiplied by the duration of employment in that zone; the resulting products were summed over the working lifetime to create the CE variable. The CE variable was divided by the total duration of employment in solvent-exposed jobs to create the LWAE variable. The explanatory value of each participant's LWAE estimate in the regression of simple visual reaction time (a neurobehavioral test previously shown to be affected by chronic solvent exposure) on exposure was compared with that of several other exposure variables, including exposure duration and an exposure variable based on an ordinal ranking of the exposure zones.(ABSTRACT TRUNCATED AT 250 WORDS)

  3. A quantitative approach to the characterization of cumulative and average solvent exposure in paint manufacturing plants

    SciTech Connect

    Ford, D.P.; Schwartz, B.S.; Powell, S.; Nelson, T.; Keller, L.; Sides, S.; Agnew, J.; Bolla, K.; Bleecker, M. )

    1991-06-01

    Previous reports have attributed a range of neurobehavioral effects to low-level, occupational solvent exposure. These studies have generally been limited in their exposure assessments and have specifically lacked good estimates of exposure intensity. In the present study, the authors describe the development of two exposure variables that quantitatively integrate industrial hygiene sampling data with estimates of exposure duration--a cumulative exposure (CE) estimate and a lifetime weighted average exposure (LWAE) estimate. Detailed occupational histories were obtained from 187 workers at two paint manufacturing plants. Historic industrial hygiene sampling data for total hydrocarbons (a composite variable of the major neurotoxic solvents present) were grouped according to 20 uniform, temporally stable exposure zones, which had been defined during plant walk-through surveys. Sampling at the time of the study was used to characterize the few zones for which historic data were limited or unavailable. For each participant, the geometric mean total hydrocarbon level for each exposure zone worked in was multiplied by the duration of employment in that zone; the resulting products were summed over the working lifetime to create the CE variable. The CE variable was divided by the total duration of employment in solvent-exposed jobs to create the LWAE variable. The explanatory value of each participant's LWAE estimate in the regression of simple visual reaction time (a neurobehavioral test previously shown to be affected by chronic solvent exposure) on exposure was compared with that of several other exposure variables, including exposure duration and an exposure variable based on an ordinal ranking of the exposure zones.

  4. Lead exposure in outdoor firearm instructors

    SciTech Connect

    Tripathi, R.K.; Sherertz, P.C.; Llewellyn, G.C.; Armstrong, C.W. )

    1991-06-01

    This study was conducted to determine lead exposure of firearm instructors at an outdoor firing range, while cadets were firing nonjacketed and jacketed lead ammunitions. The breathing zone air for lead exceeded the Occupational Safety and Health Administration standard of 50 micrograms/m3 for two instructors during firing exercises using nonjacketed bullets. The use of totally copper-jacketed bullets reduced the breathing zone lead levels by 92 percent for instructor {number sign}1 and by 96 percent for instructor {number sign}2; subsequent blood lead levels showed a significant decline in both instructors.

  5. Neurohumoral blood pressure regulation in lead exposure

    SciTech Connect

    Boscolo, P.; Carmignani, M.

    1988-06-01

    Previous human studies demonstrated that lead exposure may modify the metabolism of catecholamines and of hormones controlled by the hypothalamo-pituitary axis and may affect the kallikrein-kinin system. This paper reports unpublished data on the plasma renin activity of lead-exposed workers; these results are in agreement with those of previous human and experimental studies suggesting that the synthesis or release of renin is increased after short and moderate exposure to inorganic lead and reduced whenever the exposure is prolonged. Previous experimental investigations demonstrated that lead may act on the cardiovascular system, with effects on the renin-angiotensin system, on the reactivity to stimulation of peripheral catecholaminergic receptors, on sympathetic and vagal tone, and on reactivity to the stimulation of baroreceptors. This paper reports the results of a study on male Sprague-Dawley rats that received 0, 15, 30, and 60 ..mu..g/mL of lead in drinking water for 18 months. Blood pressure was increased in the rats receiving 30 and 60 ppm of lead; cardiac inotropism was augmented only in those receiving the higher dose of the metal, and heart rate was not modified. Cardiovascular responses to agonists indicated that lead exposure affects the renin-angiotensin system and induces sympathetic hyperactivity be acting on central and peripheral sympathetic junctions increasing the responsiveness to stimulation of ..cap alpha../sub 2/-adrenoreceptors and by increasing the reactivity to stimulation of cardiac and vascular ..beta..-adrenergic and dopaminergic receptors.

  6. Sources of lead exposure in Mexico City.

    PubMed Central

    Romieu, I; Palazuelos, E; Hernandez Avila, M; Rios, C; Muñoz, I; Jimenez, C; Cahero, G

    1994-01-01

    Many countries, including Mexico, are facing a largely unrecognized epidemic of low-level lead poisoning. Mexico is the sixth largest lead-producing country in the world, and 40% of its production is used locally in different industrial processes that cause lead contamination of the environment. The major sources and pathways of lead exposure among the Mexican population are gasoline emissions, lead-glazed ceramics, leaded paint, and lead in canned foods and beverages. In this paper we present evidence for the presence of lead in different environmental media and its impact on blood lead levels of the Mexican population. Although during the last few years important measures have been implemented to decrease lead exposure, our findings suggest that lead poisoning is still an important problem in Mexico. There is an urgent need for regulatory policies that implement stricter control to protect the Mexican population. There is also a need to develop adequate programs to reduce the lead burden and the associated health effects in the population that has been chronically exposed. Images Figure 1. PMID:7523102

  7. Sources of lead exposure in Mexico City.

    PubMed

    Romieu, I; Palazuelos, E; Hernandez Avila, M; Rios, C; Muñoz, I; Jimenez, C; Cahero, G

    1994-04-01

    Many countries, including Mexico, are facing a largely unrecognized epidemic of low-level lead poisoning. Mexico is the sixth largest lead-producing country in the world, and 40% of its production is used locally in different industrial processes that cause lead contamination of the environment. The major sources and pathways of lead exposure among the Mexican population are gasoline emissions, lead-glazed ceramics, leaded paint, and lead in canned foods and beverages. In this paper we present evidence for the presence of lead in different environmental media and its impact on blood lead levels of the Mexican population. Although during the last few years important measures have been implemented to decrease lead exposure, our findings suggest that lead poisoning is still an important problem in Mexico. There is an urgent need for regulatory policies that implement stricter control to protect the Mexican population. There is also a need to develop adequate programs to reduce the lead burden and the associated health effects in the population that has been chronically exposed.

  8. Cumulative exposure to prior collective trauma and acute stress responses to the Boston marathon bombings.

    PubMed

    Garfin, Dana Rose; Holman, E Alison; Silver, Roxane Cohen

    2015-06-01

    The role of repeated exposure to collective trauma in explaining response to subsequent community-wide trauma is poorly understood. We examined the relationship between acute stress response to the 2013 Boston Marathon bombings and prior direct and indirect media-based exposure to three collective traumatic events: the September 11, 2001 (9/11) terrorist attacks, Superstorm Sandy, and the Sandy Hook Elementary School shooting. Representative samples of residents of metropolitan Boston (n = 846) and New York City (n = 941) completed Internet-based surveys shortly after the Boston Marathon bombings. Cumulative direct exposure and indirect exposure to prior community trauma and acute stress symptoms were assessed. Acute stress levels did not differ between Boston and New York metropolitan residents. Cumulative direct and indirect, live-media-based exposure to 9/11, Superstorm Sandy, and the Sandy Hook shooting were positively associated with acute stress responses in the covariate-adjusted model. People who experience multiple community-based traumas may be sensitized to the negative impact of subsequent events, especially in communities previously exposed to similar disasters. © The Author(s) 2015.

  9. Lead exposure among lead-acid battery workers in Jamaica.

    PubMed

    Matte, T D; Figueroa, J P; Burr, G; Flesch, J P; Keenlyside, R A; Baker, E L

    1989-01-01

    To assess lead exposure in the Jamaican lead-acid battery industry, we surveyed three battery manufacturers (including 46 production workers) and 10 battery repair shops (including 23 battery repair workers). Engineering controls and respiratory protection were judged to be inadequate at battery manufacturers and battery repair shops. At manufacturers, 38 of 42 air samples for lead exceeded a work-shift time-weighted average concentration of 0.050 mg/m3 (range 0.030-5.3 mg/m3), and nine samples exceeded 0.50 mg/m3. Only one of seven air samples at repair shops exceeded 0.050 mg/m3 (range 0.003-0.066 mg/m3). Repair shop workers, however, had higher blood lead levels than manufacturing workers (65% vs. 28% with blood lead levels above 60 micrograms/dl, respectively). Manufacturing workers had a higher prevalence of safe hygienic practices and a recent interval of minimal production had occurred at one of the battery manufacturers. Workers with blood lead levels above 60 micrograms/dl tended to have higher prevalences of most symptoms of lead toxicity than did workers with lower blood lead levels, but this finding was not consistent or statistically significant. The relationship between zinc protoporphyrin concentrations and increasing blood lead concentrations was consistent with that described among workers in developed countries. The high risk of lead toxicity among Jamaican battery workers is consistent with studies of battery workers in other developing countries.

  10. Cumulative exposure estimates for polychlorinated biphenyls using a job-exposure matrix.

    PubMed

    Hopf, Nancy Brenna; Waters, Martha A; Ruder, Avima M

    2009-06-01

    PCB exposure has been associated with increased risk for cancer, neurological disease, and for birth defects in children exposed in utero. Because of the long half-lives of PCB congeners, they remain a public health problem in the United States 30 years after being banned. Workers (n=3569) at an Indiana capacitor manufacturing plant were exposed to polychlorinated biphenyls (PCBs) from 1957 to 1977. The purpose of this work was to develop a period-specific job-exposure matrix (JEM) for a follow-up epidemiologic study investigating the increased risks for cancer previously observed in the cohort. We used eight exposure determinants to estimate PCB exposures systematically. Work history, job description, capacitor production factors, PCB usage trends, and air sample data were used to develop the JEM in four steps: (1) all job titles (n=884) were assessed for exposure determinants, (2) jobs with similar exposure determinants were grouped, (3) for each job exposure category, exposure intensity (high-medium-low-background) and frequency (continuous-intermittent) were qualitatively rated separately for inhalation and dermal exposure, and (4) for each job exposure category, the product of intensity (based on air sampling data) and frequency (fraction of day exposed) was calculated. The JEM was then modified for two eras of different PCB exposure conditions. The resulting JEM consists of inhalation and dermal exposure values for 19 job exposure categories. The JEM showed an exposure-response trend associated with increased brain cancer mortality in the epidemiologic study.

  11. Ocular lens blue autofluorescence cannot be used as a measure of individual cumulative UVR exposure.

    PubMed

    Sandby-Møller, Jane; Thieden, Elisabeth; Alshede Philipsen, Peter; Schmidt, Grethe; Wulf, Hans Christian

    2004-02-01

    The accumulation of fluorophores in the ocular lens with age might be caused by ultraviolet solar radiation (UVR) exposure, but evidence of a relation between individual cumulative UVR exposure and lens autofluorescence is lacking. Individually determined UVR exposure has never before been related to lens autofluorescence, and the aim of this study was to investigate if ocular lens blue autofluorescence can be used as a biological UVR dosimeter. Ocular lens autofluorescence was quantified in vivo by fluorescence spectroscopy in 145 volunteers (108 healthy subjects, 18 with basal cell carcinoma (BCC) and 19 with cutaneous malignant melanoma (MM)). The excitation wavelength was 350 nm and the fluorescence emission was 450 nm. Individual UVR exposure data were collected both retrospectively and prospectively using questionnaires and electronic personal UVR dosimeters. Lens blue autofluorescence increased significantly with age (P=0.01), and females had significantly higher autofluorescence than males (P=0.024); the two factors explained 10% of the total variation in lens autofluorescence. Neither smoking habits nor use of glasses/contact lenses or sunglasses influenced autofluorescence. No correlations between autofluorescence and UVR exposure measurements were found, and neither was there a difference in autofluorescence between groups with high and low UVR exposure (P-values>0.1), respectively. MM patients had significantly (P=0.019) higher autofluorescence than healthy subjects when age and sex differences were taken into account; no such difference (P=0.097) was detected between BCC patients and healthy subjects. The results indicate that age and gender only play a minor role in the level of lens blue autofluorescence. Exposure to UVR has been suggested to be responsible for a part of the age-related increase in autofluorescence, but this could not be confirmed in this study. The higher level of lens autofluorescence found in MM patients might be due to genetics

  12. [Children exposure to lead in contaminated sites].

    PubMed

    Flores-Ramírez, Rogelio; Rico-Escobar, Edna; Núñez-Monreal, Jorge E; García-Nieto, Edelmira; Carrizales, Leticia; Ilizaliturri-Hernández, César; Díaz-Barriga, Fernando

    2012-01-01

    To assess the exposure to lead in children living in various types of contaminated sites. The study was conducted from June 2008 to December 2009 at four sites in Mexico: Avalos metallurgical, Chihuahua; Morales metallurgical, San Luis Potosí (SLP); Trinidad pottery area, Tlaxcala and Cedral mine site, SLP. These sites contain different sources of lead. The metal levels were quantified in outdoor dust and in peripheral blood of children. Lead dust concentrations exceed the National Guidelines for residential soils (400 mg/kg) in a range of values for the four sites from 62 to 5 187 mg/kg. Regarding biological monitoring, the studied children showed maximum lead blood levels of 22 µg/dL in Cedral, 31 µg/dL in Morales, 32 µg/dL in Avalos, and 52 µg/dL in Trinidad. It is important to mention that in all the studied sites, a significative positive correlation was found between blood lead levels and the lead concentrations in dust. These sites are an example of the health risks related to lead exposure in Mexico; therefore, there is an urgent need for a national public health program aimed at reducing lead exposure in vulnerable populations.

  13. Anemia risk in relation to lead exposure in lead-related manufacturing.

    PubMed

    Hsieh, Nan-Hung; Chung, Shun-Hui; Chen, Szu-Chieh; Chen, Wei-Yu; Cheng, Yi-Hsien; Lin, Yi-Jun; You, Su-Han; Liao, Chung-Min

    2017-05-05

    Lead-exposed workers may suffer adverse health effects under the currently regulated blood lead (BPb) levels. However, a probabilistic assessment about lead exposure-associated anemia risk is lacking. The goal of this study was to examine the association between lead exposure and anemia risk among factory workers in Taiwan. We first collated BPb and indicators of hematopoietic function data via health examination records that included 533 male and 218 female lead-exposed workers between 2012 and 2014. We used benchmark dose (BMD) modeling to estimate the critical effect doses for detection of abnormal indicators. A risk-based probabilistic model was used to characterize the potential hazard of lead poisoning for job-specific workers by hazard index (HI). We applied Bayesian decision analysis to determine whether BMD could be implicated as a suitable BPb standard. Our results indicated that HI for total lead-exposed workers was 0.78 (95% confidence interval: 0.50-1.26) with risk occurrence probability of 11.1%. The abnormal risk of anemia indicators for male and female workers could be reduced, respectively, by 67-77% and 86-95% by adopting the suggested BPb standards of 25 and 15 μg/dL. We conclude that cumulative exposure to lead in the workplace was significantly associated with anemia risk. This study suggests that current BPb standard needs to be better understood for the application of lead-exposed population protection in different scenarios to provide a novel standard for health management. Low-level lead exposure risk is an occupational and public health problem that should be paid more attention.

  14. Estimating the distribution of lifetime cumulative radon exposures for California residents: A brief summary

    SciTech Connect

    Liu, K.S.; Chang, Y.L.; Hayward, S.B.; Gadgil, A.J.; Nero, A.V. Jr.

    1992-04-01

    We have used data on residential radon concentrations in California, together with information on California residents` moving histories and time-activity patterns, to estimate the distribution of lifetime cumulative exposures to radon 222. This distribution was constructed using Monte Carlo techniques to simulate the lifetime occupancy histories -- and associated radon exposures -- of 10,000 California residents. For standard male and female lifespans, the simulation sampled from transition probability matrices representing changes of residence within and between six regions of California, as well as into and out of the other United States, and then sampled from the appropriate regional (or national) distribution of indoor concentrations. The resulting distribution of lifetime cumulative exposures has a significantly narrower relative width than the distribution of California indoor concentrations, with only a small fraction -- less than 0.2% -- of the population having lifetime exposures equivalent to living during their lifetimes in a single home with a radon concentration of 148 Bq/m{sup 3} or more.

  15. Human lead exposure: Some recent research findings

    SciTech Connect

    Saryan, L.A.

    1999-09-01

    One of the practical problems facing industrial hygienists and safety managers in the lead industry is finding new ways to limit or reduce lead intake in order to protect workers from the deleterious effects of this metal. Exposure to lead generally takes place by inhalation of airborne particles and by ingestion. Airborne exposure is comparatively well understood and methods for the control of airborne lead have been developed and put into place in industrial facilities. Both for the general public and for workers, however, it is thought that a significant fraction of the total lead intake occurs by ingestion as opposed to inhalation. Furthermore, factors such as personal hygiene, hand washing, diet, cigarette smoking, alcohol consumption, use of medications, bone injury, existing disease, and others may also have positive or negative effects on lead absorption and blood lead levels. How these variables actually operate in practice for lead-exposed workers is unfortunately not very well understood. As scientific and medical knowledge increases, progress has been made in the understanding of some of the factors affecting blood lead levels. In this article, the author summarizes the findings of a few interesting recent reports that point the way toward future progress in this area.

  16. Neural alterations from lead exposure in zebrafish.

    PubMed

    Roy, Nicole M; DeWolf, Sarah; Schutt, Alexius; Wright, Ashia; Steele, Latina

    2014-01-01

    Lead was used extensively as a gas additive and pesticide, in paints, batteries, lead shot, pipes, canning and toy manufacturing. Although uses of lead have been restricted, lead persists in our environment especially in older homes, and generally in soil and water. Although extensive studies have determined that fetal and childhood exposures to lead have been associated with childhood and adolescent memory impairments and learning disabilities, there are limited studies investigating early neural and morphological effects that may lead to these behavioral and learning abnormalities. Here we utilize the zebrafish vertebrate model system to study early effects of lead exposure on the brain. We treat embryos with 0.2mM lead for 24, 48 and 72 h and analyze neural structures through live imagery and transgenic approaches. We find structural abnormalities in the hindbrain region as well as changes in branchiomotor neuron development and altered neural vasculature. Additionally, we find areas of increased apoptosis. We conclude that lead is developmentally neurotoxic to a specific region of the brain, the hindbrain and is toxic to branchiomotor neurons residing in rhombomeres 2 through 7 of the hindbrain and hindbrain central artery vasculature.

  17. EPA's SHEDS-multimedia model: children's cumulative pyrethroid exposure estimates and evaluation against NHANES biomarker data.

    PubMed

    Xue, Jianping; Zartarian, Valerie; Tornero-Velez, Rogelio; Tulve, Nicolle S

    2014-12-01

    The U.S. EPA's SHEDS-Multimedia model was applied to enhance the understanding of children's exposures and doses to multiple pyrethroid pesticides, including major contributing chemicals and pathways. This paper presents combined dietary and residential exposure estimates and cumulative doses for seven commonly used pyrethroids, and comparisons of model evaluation results with NHANES biomarker data for 3-PBA and DCCA metabolites. Model input distributions were fit to publicly available pesticide usage survey data, NHANES, and other studies, then SHEDS-Multimedia was applied to estimate total pyrethroid exposures and doses for 3-5 year olds for one year variability simulations. For dose estimations we used a pharmacokinetic model and two approaches for simulating dermal absorption. SHEDS-Multimedia predictions compared well to NHANES biomarker data: ratios of 3-PBA observed data to SHEDS-Multimedia modeled results were 0.88, 0.51, 0.54 and 1.02 for mean, median, 95th, and 99th percentiles, respectively; for DCCA, the ratios were 0.82, 0.53, 0.56, and 0.94. Modeled time-averaged cumulative absorbed dose of the seven pyrethroids was 3.1 nmol/day (versus 8.4 nmol/day for adults) in the general population (residential pyrethroid use and non-use homes) and 6.7 nmol/day (versus 10.5 nmol/day for adults) in the simulated residential pyrethroid use population. For the general population, contributions to modeled cumulative dose by chemical were permethrin (60%), cypermethrin (22%), and cyfluthrin (16%); for residential use homes, contributions were cypermethrin (49%), permethrin (29%), and cyfluthrin (17%). The primary exposure route for 3-5 year olds in the simulated residential use population was non-dietary ingestion exposure; whereas for the simulated general population, dietary exposure was the primary exposure route. Below the 95th percentile, the major exposure pathway was dietary for the general population; non-dietary ingestion was the major pathway starting below

  18. Neurohumoral blood pressure regulation in lead exposure.

    PubMed Central

    Boscolo, P; Carmignani, M

    1988-01-01

    Previous human studies demonstrated that lead exposure may modify the metabolism of catecholamines and of hormones controlled by the hypothalamo-pituitary axis and may affect the kallikrein-kinin system. This paper reports unpublished data on the plasma renin activity of lead-exposed workers; these results are in agreement with those of previous human and experimental studies suggesting that the synthesis or release of renin is increased after short and moderate exposure to inorganic lead and reduced whenever the exposure is prolonged. Previous experimental investigations demonstrated that lead may act on the cardiovascular system, with effects on the renin-angiotensin system, on the reactivity to stimulation of peripheral catecholaminergic receptors, on sympathetic and vagal tone, and on reactivity to the stimulation of baroreceptors. This paper reports the results of a study on male Sprague-Dawley rats that received 0, 15, 30, and 60 micrograms/mL of lead in drinking water for 18 months. Blood pressure was increased in the rats receiving 30 and 60 ppm of lead; cardiac inotropism was augmented only in those receiving the higher dose of the metal, and heart rate was not modified. Cardiovascular responses to agonists indicated that lead exposure affects the renin-angiotensin system and induces sympathetic hyperactivity by acting on central and peripheral sympathetic junctions increasing the responsiveness to stimulation of alpha 2-adrenoreceptors and by increasing the reactivity to stimulation of cardiac and vascular beta-adrenergic and dopaminergic receptors. The cAMP-dependent availability of Ca2+ for contractile mechanisms of the cardiovascular muscle cells was affected by lead. PMID:3060351

  19. Threshold exceedances and cumulative ozone exposure indices at tropical suburban site

    NASA Astrophysics Data System (ADS)

    Beig, G.; Ghude, Sachin D.; Polade, S. D.; Tyagi, B.

    2008-01-01

    This study provides the first analysis of threshold exceedances and cumulative ozone exposure indices from Pune, a tropical suburban site in India. We used the directives on ozone pollution in ambient air provided by the United Nations Economic Commission for Europe, and by the World Health Organization to assess the air quality from in situ measurements of surface ozone (during the years 2003-2006). We find that the exposure-plant response index (Accumulated exposure Over a Threshold of 40 ppb (AOT40)) and target values for protection of human health (8-h > 60 ppb) are regularly surpassed. This is a concern for agricultural and human health. Air-mass classification based on back-air trajectories shows that the excess of AOT40 values is quite plausibly due to long-range transport of background ozone and its precursors to the measurement site.

  20. Finite-time full counting statistics and factorial cumulants for transport through a quantum dot with normal and superconducting leads

    NASA Astrophysics Data System (ADS)

    Droste, Stephanie; Governale, Michele

    2016-04-01

    We study the finite-time full counting statistics for subgap transport through a single-level quantum dot tunnel-coupled to one normal and one superconducting lead. In particular, we determine the factorial and the ordinary cumulants both for finite times and in the long-time limit. We find that the factorial cumulants violate the sign criterion, indicating a non-binomial distribution, even in absence of Coulomb repulsion due to the presence of superconducting correlations. At short times the cumulants exhibit oscillations which are a signature of the coherent transfer of Cooper pairs between the dot and the superconductor.

  1. Lead exposure from aluminum cookware in Cameroon.

    PubMed

    Weidenhamer, Jeffrey D; Kobunski, Peter A; Kuepouo, Gilbert; Corbin, Rebecca W; Gottesfeld, Perry

    2014-10-15

    Blood lead levels have decreased following the removal of lead from gasoline in most of the world. However, numerous recent studies provide evidence that elevated blood lead levels persist in many low and middle-income countries around the world at much higher prevalence than in the more developed countries. One potential source of lead exposure that has not been widely investigated is the leaching of lead from artisanal aluminum cookware, which is commonly used in the developing world. Twenty-nine samples of aluminum cookware and utensils manufactured by local artisans in Cameroon were collected and analyzed for their potential to release lead during cooking. Source materials for this cookware included scrap metal such as engine parts, radiators, cans, and construction materials. The lead content of this cookware is relatively low (<1000 ppm by X-ray fluorescence), however significant amounts of lead, as well as aluminum and cadmium were released from many of the samples using dilute acetic acid extractions at boiling and ambient temperatures. Potential exposures to lead per serving were estimated to be as high as 260 μg, indicating that such cookware can pose a serious health hazard. We conclude that lead, aluminum and cadmium can migrate from this aluminum cookware during cooking and enter food at levels exceeding recommended public health guidelines. Our results support the need to regulate lead content of materials used to manufacture these pots. Artisanal aluminum cookware may be a major contributor to lead poisoning throughout the developing world. Testing of aluminum cookware in other developing countries is warranted.

  2. Estimation of individual cumulative ultraviolet exposure using a geographically-adjusted, openly-accessible tool.

    PubMed

    Zhu, Gefei A; Raber, Inbar; Sakshuwong, Sukolsak; Li, Shufeng; Li, Angela S; Tan, Caroline; Chang, Anne Lynn S

    2016-01-20

    Estimates of an individual's cumulative ultraviolet (UV) radiation exposure can be useful since ultraviolet radiation exposure increases skin cancer risk, but a comprehensive tool that is practical for use in the clinic does not currently exist. The objective of this study is to develop a geographically-adjusted tool to systematically estimate an individual's self-reported cumulative UV radiation exposure, investigate the association of these estimates with skin cancer diagnosis, and assess test reliability. A 12-item online questionnaire from validated survey items for UV exposure and skin cancer was administered to online volunteers across the United States and results cross-referenced with UV radiation indices. Cumulative UV exposure scores (CUES) were calculated and correlated with personal history of skin cancer in a case-control design. Reliability was assessed in a separate convenience sample. 1,118 responses were included in the overall sample; the mean age of respondents was 46 (standard deviation 15, range 18 - 81) and 150 (13 %) reported a history of skin cancer. In bivariate analysis of 1:2 age-matched cases (n = 149) and controls (n = 298), skin cancer cases were associated with (1) greater CUES prior to first skin cancer diagnosis than controls without skin cancer history (242,074 vs. 205,379, p = 0.003) and (2) less engagement in UV protective behaviors (p < 0.01). In a multivariate analysis of age-matched data, individuals with CUES in the lowest quartile were less likely to develop skin cancer compared to those in the highest quartile. In reliability testing among 19 volunteers, the 2-week intra-class correlation coefficient for CUES was 0.94. We have provided the programming code for this tool as well as the tool itself via open access. CUES is a useable and comprehensive tool to better estimate lifetime ultraviolet exposure, so that individuals with higher levels of exposure may be identified for counseling on photo

  3. Environmental justice, local knowledge, and risk: the discourse of a community-based cumulative exposure assessment.

    PubMed

    Corburn, Jason

    2002-04-01

    While risk assessment continues to drive most environmental management decision-making, its methods and assumptions have been criticized for, among other things, perpetuating environmental injustice. The justice challenges to risk assessment claim that the process ignores the unique and multiple hazards facing low-income and people of color communities and simultaneously excludes the local, non-expert knowledge which could help capture these unique hazards from the assessment discourse. This paper highlights some of these challenges to conventional risk assessment and suggests that traditional models of risk characterization will continue to ignore the environmental justice challenges until cumulative hazards and local knowledge are meaningfully brought into the assessment process. We ask whether a shift from risk to exposure assessment might enable environmental managers to respond to the environmental justice critiques. We review the US EPA's first community-based Cumulative Exposure Project, piloted in Brooklyn, NY, and highlight to what extent this process addressed the risk assessment critiques raised by environmental justice advocates. We suggest that a shift from risk to exposure assessment can provide an opportunity for local knowledge to both improve the technical assessment and its democratic nature and may ultimately allow environmental managers to better address environmental justice concerns in decision-making.

  4. Cumulative social risk exposure, infant birth weight, and cognitive delay in infancy.

    PubMed

    Cheng, Erika R; Poehlmann-Tynan, Julie; Mullahy, John; Witt, Whitney P

    2014-01-01

    To determine the effect of exposure to multiple social risks on cognitive delay at 9 months of age; and whether obstetric factors mediate the relationship between cumulative social risk and cognitive delay. Data were from 8950 mother-child dyads participating in the first wave of the Early Childhood Longitudinal Study, Birth Cohort. Cognitive delay was defined as falling in the lowest 10% of mental scale scores from the Bayley Short Form-Research Edition. Five social risk factors were combined and categorized into a social risk index. Staged multivariable logistic regressions were used to investigate whether obstetric factors mediated the impact of social risk on the odds of cognitive delay. Infants with cognitive delay were more likely to live with social risks than infants without cognitive delay. The percentage of infants with cognitive delay increased with the number of social risks. In adjusted analyses, exposure to multiple social risk factors was associated with higher odds of cognitive delay at 9 months of age (adjusted odds ratio 2.11; 95% confidence interval 1.18-3.78 for 4 or more risks vs no risks). Accounting for birth weight attenuated this relationship (P < .001). This population-based study investigated the independent and cumulative effects of social risk factors on cognitive delay in infancy. Findings revealed a significant cumulative relationship between exposure to social risk and cognitive delay, which was partly mediated by birth weight. Programs that address the social context of US infants are needed to improve their developmental trajectories. Copyright © 2014 Academic Pediatric Association. Published by Elsevier Inc. All rights reserved.

  5. Long-term exposure to high air pollution induces cumulative DNA damages in traffic policemen.

    PubMed

    Tan, Chaochao; Lu, Shijie; Wang, Yupeng; Zhu, Yan; Shi, Ting; Lin, Mingyue; Deng, Zhonghua; Wang, Zhu; Song, Nana; Li, Shuna; Yang, Pingting; Yang, Liyan; Liu, Yuanyuan; Chen, Zhiheng; Xu, Keqian

    2017-09-01

    The specific effects of long-term exposure to high air pollution on human health and biological remain unclear. To explore the adverse health effects as well as biological mechanisms and biomarkers for durative exposure to air pollution, 183 traffic policemen and 88 office policemen were enrolled in this study. The concentration of PM2.5 in both the traffic and office policemen's working environments were obtained. Detailed personal questionnaires were completed and levels of inflammation, oxidative stress and DNA damage markers of all participants were analyzed in this study. The average PM2.5 concentration of the intersections of main roads and the offices of control group were 132.4±48.9μg/m(3) and 50.80±38.6μg/m(3), respectively. The traffic policemen, who stably exposed to at least 2 times higher PM2.5 in their work area as compared with the control group, have a median average duration of 7.00years, and average cumulative intersection duty time reached 8030h. No statistically significant differences in the levels of inflammation markers were observed between the traffic and office policemen. However, the DNA damage markers in traffic policemen shared significant positive correlation with cumulative intersection duty time and higher than those in the office policemen. Multiple linear regression analysis demonstrated that the increase of cumulative intersection duty time by 1h per day for one year was associated with the increase in 8-hydroxy-20-deoxyguanosine of 0.329% (95% CI: 0.249% to 0.409%), tail DNA of 0.051% (95% CI: 0.041% to 0.061%), micronucleus frequency of 0.036‰ (95% CI: 0.03‰ to 0.043‰), and a decrease in glutathione of 0.482% (95% CI: -0.652% to -0.313%). These findings suggest that long-term exposure to high air pollution could induce cumulative DNA damages, supporting the hypothesis that durative exposure to air pollution is associated with an increased risk of cancer. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. [Lead exposure among Kaohsiung traffic policemen].

    PubMed

    Chiang, H C; Chang, P Y

    1989-06-01

    In this recent century there has been increasing concern over the possible harmful effects of lead from automobile exhaust on human health. Traffic policemen are heavily exposed to automobile exhaust. In Kaohsiung city because of the increasing number of motor vehicles due to rapid urbanization and heavy traffic transportation from suburbs for export trade, traffic policemen have varied exposure experiences. The automobile exhaust of lead additive gasoline was found to be the major type of exposure for traffic policemen whose duties were in the city, while those who worked in the suburb areas were generally exposed to diesel oil exhaust gas. In this study 98 traffic policemen were studied with 118 students used as a control group. Subjects were evaluated for lead absorption and other metabolic effects. The average value of blood lead for traffic policemen (24.43 +/- 5.31 micrograms/dl) in the city of Kaohsiung was significantly (p less than 0.01) higher than for the control group (20.14 +/- 5.07 micrograms/dl). According to other bioindicators it was also found that the mean values of carboxyhemoglobin, urine lead and urine coproporphyrin were significantly higher in the traffic policemen group. Linear regression between blood lead and the duration of employment was also found in this study (R = -0.2447, p less than 0.05). The most reasonable explanations for these findings are the effects of lead emission from motor vehicles and the employment shifting system that cause this effect.

  7. Lead exposure and radiator repair work

    SciTech Connect

    Lussenhop, D.H.; Parker, D.L.; Barklind, A.; McJilton, C. )

    1989-11-01

    In 1986, the ambient air for lead in radiator repair shops in the Minneapolis-St. Paul metropolitan area exceeded the Occupational Safety and Health Administration (OSHA) action level in nine of 12 shops sampled by Minnesota OSHA. We therefore sought to determine the prevalence of lead exposure/toxicity in this industry. Thirty-five radiator shops were identified, 30 were visited, and 53 workers were studied. The mean blood lead level was 1.53 (range 0.24-2.80). Seventeen individuals had blood lead levels greater than or equal to 1.93 mumol/L (40 micrograms/dl). The mean zinc protoporphyrin level (ZPP) was 0.55 mumol/L (range 0.16-1.43). No single worksite or personal characteristic was a strong determinant of either blood lead or ZPP level.

  8. Lead exposure and radiator repair work.

    PubMed Central

    Lussenhop, D H; Parker, D L; Barklind, A; McJilton, C

    1989-01-01

    In 1986, the ambient air for lead in radiator repair shops in the Minneapolis-St. Paul metropolitan area exceeded the Occupational Safety and Health Administration (OSHA) action level in nine of 12 shops sampled by Minnesota OSHA. We therefore sought to determine the prevalence of lead exposure/toxicity in this industry. Thirty-five radiator shops were identified, 30 were visited, and 53 workers were studied. The mean blood lead level was 1.53 (range 0.24-2.80). Seventeen individuals had blood lead levels greater than or equal to 1.93 mumol/L (40 micrograms/dl). The mean zinc protoporphyrin level (ZPP) was 0.55 mumol/L (range 0.16-1.43). No single worksite or personal characteristic was a strong determinant of either blood lead or ZPP level. PMID:2817174

  9. Lead exposure and radiator repair work.

    PubMed

    Lussenhop, D H; Parker, D L; Barklind, A; McJilton, C

    1989-11-01

    In 1986, the ambient air for lead in radiator repair shops in the Minneapolis-St. Paul metropolitan area exceeded the Occupational Safety and Health Administration (OSHA) action level in nine of 12 shops sampled by Minnesota OSHA. We therefore sought to determine the prevalence of lead exposure/toxicity in this industry. Thirty-five radiator shops were identified, 30 were visited, and 53 workers were studied. The mean blood lead level was 1.53 (range 0.24-2.80). Seventeen individuals had blood lead levels greater than or equal to 1.93 mumol/L (40 micrograms/dl). The mean zinc protoporphyrin level (ZPP) was 0.55 mumol/L (range 0.16-1.43). No single worksite or personal characteristic was a strong determinant of either blood lead or ZPP level.

  10. Health risks of children's cumulative and aggregative exposure to metals and metalloids in a typical urban environment in China.

    PubMed

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Chen, Yiting; Wang, Beibei; Sun, Chengye; Zheng, Binghui; Wei, Fusheng

    2016-03-01

    Rapid development of industrialization and urbanization results in serious environmental contamination by metal(loid)s, which would consequently cause deleterious health effects to the exposed people through multi-pathways. Therefore, total health risk assessment for the population in urban environment is very important. Unfortunately, few studies to date investigate the cumulative health risks of metal(loid)s through aggregative pathways in Children who are often susceptible population. 12 metal(loid)s including Lead(Pb), Cadmium(Cd), Arsenic(As), Chromium(Cr), Zinc(Zn), Copper(Cu), Nickel(Ni), Manganese(Mn), Cobalt(Co), Selenium(Se), Antimony(Se) and Vanadium(V), were analyzed in PM10, drinking water, food, soil and indoor dust in this study. The cumulative and aggregative risks of these metal(loid)s among the local children were then evaluated on a field sampling and questionnaire-survey basis. The results showed that the environments were heavily polluted by metal(loid)s. For most metal(loid)s, food ingestion accounted for more than 80% of the total daily exposure dose. The non-cancer risks were up to 30 times higher than the acceptable level due to the food ingestion via Pb, Cr, Cu, Zn, As, Se, Cd and Sb, and the PM10 inhalation via Cr and Mn. While, the cancer risks were mainly attributed to Cr via food ingestion and As via food and dust ingestion, and approximately 100 times of the maximum acceptable level of 1.0 × 10(-4). The study highlights the cumulative and aggregative exposure assessment, instead of pollutant investigation to evaluate the potential health risks and emphasizes concerns to improve indoor hygienic and environmental quality and to decrease the potential harmful health effects of children living in urban area.

  11. Measured Head CT/CTA Skin Dose and Intensive Care Unit Patient Cumulative Exposure.

    PubMed

    Nawfel, R D; Young, G S

    2017-03-01

    Estimates of cumulative CT/CTA radiation dose based on volumetric CT dose index have raised concern that neurological intensive care unit patient exposures may reach thresholds for deterministic skin injury. Because the accuracy of volumetric CT dose index for this purpose in unknown, we set out to directly measure head CT and CTA peak skin dose, assess the relationship of volumetric CT dose index to measured peak skin dose, and determine whether multiple CT/CTA exposures in typical patients in the neurological intensive care unit produce cumulative doses approaching or exceeding single-dose deterministic thresholds for skin injury. In a prospective study from 2011-2013, nanoDot optical stimulated luminescence dosimeters were used to measure head CT/CTA peak skin dose in 52 patients (28 female, 24 male; mean age, 63 years) divided equally between 2 CT scanners. Volumetric CT dose index and dose-length product were recorded for each examination. Peak skin dose was also measured on an acrylic skull phantom in each scanner. A 2-tailed, unpaired t test was used to compare mean patient skin doses between the 2 scanners. The measured peak skin doses were then used to calculate cumulative peak skin dose in 4 typical patients in intensive care units who received multiple CT/CTA scans. Head CT/CTA peak skin dose agreed between scanners in patients and phantoms: (scanner 1 CT/CTA: patients, 39.2 ± 3.7 mGy and 98.9 ± 5.3 mGy, respectively, versus phantom, 40.0 mGy and 105.4 mGy, respectively; scanner 2 CT/CTA: patients, 42.9 ± 9.4 mGy and 98.8 ± 7.4 mGy, respectively, versus phantom, 37.6 mGy and 95.2 mGy, respectively). Volumetric CT dose index overestimated peak skin dose by a factor of 1.4-1.9 depending on examination and CT scanner. Cumulative doses in 4 patients in the intensive care unit estimated from measured CT/CTA peak skin dose ranged from 1.9-4.5 Gy. Directly measured radiation skin doses from head CT/CTA patient examinations are substantially lower than

  12. Cumulative radiation exposure from imaging procedures and associated lifetime cancer risk for patients with lymphoma

    PubMed Central

    Fabritius, Grete; Brix, Gunnar; Nekolla, Elke; Klein, Stefan; Popp, Henning D.; Meyer, Mathias; Glatting, Gerhard; Hagelstein, Claudia; Hofmann, Wolf K.; Schoenberg, Stefan O.; Henzler, Thomas

    2016-01-01

    The aim of this study was to systematically evaluate the cumulative radiation exposure and the associated lifetime-cancer-risk from diagnostic imaging in patients with Hodgkin-lymphoma-(HL) or diffuse-large-B-cell-lymphoma (DLBCL). 99 consecutive patients (53-males) diagnosed with HL or DLBCL were included in the study and followed. Based on the imaging reports, organ and effective-doses-(ED) were calculated individually for each patient and the excess lifetime risks were estimated. The average ED in the first year after diagnosis was significantly different for men (59 ± 33 mSv) and women (744 ± 33 mSv)-(p < 0.05). The mean cumulative ED in each of the following 5 years was 16 ± 16 mSv without significant differences between men and women-(p > 0.05). Over all years, more than 90% of the ED resulted from CT. The average cumulative radiation risk estimated for the first year was significantly lower for men (0.76 ± 0.41%) as compared to women (1.28 ± 0.54%)-(p < 0.05). The same was found for each of the subsequent 5-years (men-0.18 ± 0.17%; women-0.28 ± 0.25%)-(p < 0.05). In conclusion, for HL and DLBCL patients investigated in this study, a cumulative radiation risk of about 1 excess cancer per 100 patients is estimated for diagnostic imaging procedures performed during both the first year after diagnosis and a follow-up period of 5 years. PMID:27748377

  13. Lead exposure in Mexican radiator repair workers.

    PubMed

    Dykeman, Ronald; Aguilar-Madrid, Guadalupe; Smith, Tom; Juárez-Pérez, Cuauhtemoc Arturo; Piacitelli, Gregory M; Hu, Howard; Hernandez-Avila, Mauricio

    2002-03-01

    Lead exposure was investigated among 73 Mexican radiator repair workers (RRWs), 12 members of their family (4 children and 8 wives), and 36 working controls. RRWs were employed at 4 radiator repair shops in Mexico City and 27 shops in Cuernavaca and surrounding areas. Exposure was assessed directly through the use of personal air sampling and hand wipe samples. In addition, industrial hygiene inspections were performed and detailed questionnaires were administered. Blood lead levels were measured by graphite furnace atomic absorption spectroscopy (AAS). The mean (SD) values for blood lead of the RRWs, 35.5 (13.5) microg/dl, was significantly greater than the same values for the working controls, 13.6 (8.7) microg/dl; P < 001. After excluding a single outlier (247 microg/m(3)), air lead levels ranged from 0 to 99 microg/m(3) with a mean (SD) value of 19 (23) microg/m(3) (median = 7.9 microg/m(3)). In a final multivariate regression model of elevated blood lead levels, the strongest predictors were smoking (vs. non-smoking), the number of radiators repaired per day on average, and the use (vs. non-use) of a uniform while at work, which were associated with blood lead elevations of 11.4 microg/dl, 1.95 microg/dl/radiator/day, and 16.4 microg/dl, respectively (all P <.05). Uniform use was probably a risk factor because they were not laundered regularly and consequently served as reservoir of contamination on which RRWs frequently wiped their hands. Lead exposure is a significant problem of radiator repair work, a small industry that is abundant in Mexico and other developing countries. Copyright 2002 Wiley-Liss, Inc.

  14. Psychobiology of cumulative trauma: hair cortisol as a risk marker for stress exposure in women.

    PubMed

    Morris, Matthew C; Abelson, James L; Mielock, Alyssa S; Rao, Uma

    2017-07-01

    Childhood trauma (CT) is associated with long-lasting alterations of the hypothalamic-pituitary-adrenal (HPA) axis and elevated risk for stress exposure in adulthood. Although HPA alterations are present in the early aftermath of trauma, it remains unclear how initial HPA activity is associated with subsequent stress exposure and whether CT exposure influences the strength and direction of this association. The present study examined prospective associations between hair cortisol content (HCC) and stress exposure from baseline to 3-month follow-up in young adult women with recent (i.e. past 3 months) exposure to interpersonal violence (IPV; i.e. physical or sexual assault) and non-traumatized controls. History of significant CT abuse or neglect was determined based on clinical cutoffs for a self-report CT measure: 12 women had abuse or neglect and recent IPV exposure (CT + IPV); 7 women had abuse or neglect but no IPV exposure (CT); 15 women had no history of trauma (NTC). HCC was computed for 3 cm sections reflecting cortisol secretion during the 3 months preceding the baseline assessment. The interaction of cumulative trauma and HCC predicted stress exposure over 3-month follow-up, controlling for baseline stress exposure and depressive symptoms. Simple slopes analyses revealed that lower baseline HCC predicted greater stress exposure in the CT + IPV group compared to the CT group; HCC was not associated with stress exposure in the NTC group. The present findings highlight the potential utility of HCC as a predictor of stress exposure for women with a history of childhood abuse or neglect, particularly in the context of recent IPV. Lay summary Adults with a history of CT show long-lasting alterations in major stress response systems, including the HPA axis. They are also more likely to experience stressful life events in adulthood. However, it is not clear how altered HPA activity influences risk for stress exposure and whether CT affects their

  15. [Lead exposure of people living in a lead high exposure area from local diet].

    PubMed

    Zhou, Yong; He, Liping; Huang, Xiao; He, Junshan

    2011-11-01

    To study the lead exposure of people living in a lead high exposure area from local diet, and to assess its health risks. Thirty five subjects were selected by random from a mining area and another 30 subjects were selected from a non-polluted area. The exposure of lead was estimated by the content of lead in drinking water and vegetables, and health risks was estimated by the levels of lead in blood and urine. The content of lead in drinking water and vegetables in the mining area was 20.6 microg/L and 1.61mg/kg (geometric mean) respectively, which were higher than that in the unpolluted area (6.0 microg/L and 0.56 mg/kg, geometric mean) (P < 0.01). The daily lead exposure of male and female inhabitants in the mining area from diet was 16.88 microg/kg and 16.09 microg/kg respectively, which was higher than that in the unpolluted area (P < 0.01), but the sex difference was not significant statistically (P > 0.05). Blood lead and urine lead of inhabitants in the mining-area were higher than those in the unpolluted area. The health risks for male and female inhabitants in the mining area were 4.73 and 4.51. The health risks of lead exposure caused by diet (drinking water and food) were relatively high in the mining area.

  16. Modeling Joint Exposures and Health Outcomes for Cumulative Risk Assessment: The Case of Radon and Smoking

    PubMed Central

    Chahine, Teresa; Schultz, Bradley D.; Zartarian, Valerie G.; Xue, Jianping; Subramanian, SV; Levy, Jonathan I.

    2011-01-01

    Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case example, given its large attributable risk, effect modification due to smoking, and significant variability in radon concentrations and smoking patterns. In spite of this fact, no study to date has estimated geographic and sociodemographic patterns of both radon and smoking in a manner that would allow for inclusion of radon in community-based cumulative risk assessment. In this study, we apply multi-level regression models to explain variability in radon based on housing characteristics and geological variables, and construct a regression model predicting housing characteristics using U.S. Census data. Multi-level regression models of smoking based on predictors common to the housing model allow us to link the exposures. We estimate county-average lifetime lung cancer risks from radon ranging from 0.15 to 1.8 in 100, with high-risk clusters in areas and for subpopulations with high predicted radon and smoking rates. Our findings demonstrate the viability of screening-level assessment to characterize patterns of lung cancer risk from radon, with an approach that can be generalized to multiple chemical and non-chemical stressors. PMID:22016710

  17. Modeling joint exposures and health outcomes for cumulative risk assessment: the case of radon and smoking.

    PubMed

    Chahine, Teresa; Schultz, Bradley D; Zartarian, Valerie G; Xue, Jianping; Subramanian, S V; Levy, Jonathan I

    2011-09-01

    Community-based cumulative risk assessment requires characterization of exposures to multiple chemical and non-chemical stressors, with consideration of how the non-chemical stressors may influence risks from chemical stressors. Residential radon provides an interesting case example, given its large attributable risk, effect modification due to smoking, and significant variability in radon concentrations and smoking patterns. In spite of this fact, no study to date has estimated geographic and sociodemographic patterns of both radon and smoking in a manner that would allow for inclusion of radon in community-based cumulative risk assessment. In this study, we apply multi-level regression models to explain variability in radon based on housing characteristics and geological variables, and construct a regression model predicting housing characteristics using U.S. Census data. Multi-level regression models of smoking based on predictors common to the housing model allow us to link the exposures. We estimate county-average lifetime lung cancer risks from radon ranging from 0.15 to 1.8 in 100, with high-risk clusters in areas and for subpopulations with high predicted radon and smoking rates. Our findings demonstrate the viability of screening-level assessment to characterize patterns of lung cancer risk from radon, with an approach that can be generalized to multiple chemical and non-chemical stressors.

  18. Associations of cumulative sun exposure and phenotypic characteristics with histologic solar elastosis

    PubMed Central

    Thomas, Nancy E.; Kricker, Anne; From, Lynn; Busam, Klaus; Millikan, Robert C.; Ritchey, Mary E.; Armstrong, Bruce K.; Lee-Taylor, Julia; Marrett, Loraine D.; Anton-Culver, Hoda; Zanetti, Roberto; Rosso, Stefano; Gallagher, Richard P.; Dwyer, Terence; Goumas, Chris; Kanetsky, Peter A.; Begg, Colin B.; Orlow, Irene; Wilcox, Homer; Paine, Susan; Berwick, Marianne

    2010-01-01

    Background Solar elastosis adjacent to melanomas in histologic sections is regarded as an indicator of sun exposure although the associations of ultraviolet (UV) exposure and phenotype with solar elastosis are yet to be fully explored. Methods The study included 2,589 incident primary melanoma patients with assessment of histologic solar elastosis in the population-based Genes, Environment, and Melanoma study. Ambient erythemal UV (UVE) at places of residence and sun exposure hours, including body site-specific exposure, were collected. We examined the association of cumulative site-specific and non site-specific sun exposure hours and ambient UVE with solar elastosis in multivariable models adjusted for age, sex, center, pigmentary characteristics, nevi and, where relevant, body site. Results Solar elastosis was associated most strongly with site-specific UVE (OR for top exposure quartile, 5.20; 95% CI, 3.40-7.96; P for trend <0.001) and also with site-specific sun exposure (OR for top quartile, 5.12; 95% CI, 3.35-7.83; P for trend <0.001). Older age (OR at >70 years, 7.69; 95% CI, 5.14-11.52); P trend < 0.001) and having more than 10 back nevi (OR, 0.77; 95% CI, 0.61-0.97; P = 0.03) were independently associated with solar elastosis. Conclusion Solar elastosis had a strong association with higher site-specific UVE dose, older age and fewer nevi. Impact Solar elastosis could be a useful biomarker of lifetime site-specific UV. Future research is needed to explore whether age represents more than simple accumulation of sun exposure and the reason that people with more nevi may be less prone to solar elastosis. PMID:20802019

  19. Associations of cumulative sun exposure and phenotypic characteristics with histologic solar elastosis.

    PubMed

    Thomas, Nancy E; Kricker, Anne; From, Lynn; Busam, Klaus; Millikan, Robert C; Ritchey, Mary E; Armstrong, Bruce K; Lee-Taylor, Julia; Marrett, Loraine D; Anton-Culver, Hoda; Zanetti, Roberto; Rosso, Stefano; Gallagher, Richard P; Dwyer, Terence; Goumas, Chris; Kanetsky, Peter A; Begg, Colin B; Orlow, Irene; Wilcox, Homer; Paine, Susan; Berwick, Marianne

    2010-11-01

    Solar elastosis adjacent to melanomas in histologic sections is regarded as an indicator of sun exposure, although the associations of UV exposure and phenotype with solar elastosis are yet to be fully explored. The study included 2,589 incident primary melanoma patients with assessment of histologic solar elastosis in the population-based Genes, Environment, and Melanoma study. Ambient erythemal UV (UVE) at places of residence and sun exposure hours, including body site-specific exposure, were collected. We examined the association of cumulative site-specific and non-site-specific sun exposure hours and ambient UVE with solar elastosis in multivariable models adjusted for age, sex, center, pigmentary characteristics, nevi, and, where relevant, body site. Solar elastosis was associated most strongly with site-specific UVE [odds ratio (OR) for top exposure quartile, 5.20; 95% confidence interval (95% CI), 3.40-7.96; P for trend <0.001] and also with site-specific sun exposure (OR for top quartile, 5.12; 95% CI, 3.35-7.83; P for trend <0.001). Older age (OR at >70 years, 7.69; 95% CI, 5.14-11.52; P for trend < 0.001) and having more than 10 back nevi (OR, 0.77; 95% CI, 0.61-0.97; P = 0.03) were independently associated with solar elastosis. Solar elastosis had a strong association with higher site-specific UVE dose, older age, and fewer nevi. Solar elastosis could be a useful biomarker of lifetime site-specific UV. Future research is needed to explore whether age represents more than simple accumulation of sun exposure and to determine why people with more nevi may be less prone to solar elastosis. ©2010 AACR.

  20. Actual and Potential Radiation Exposures in Digital Radiology: Analysis of Cumulative Data, Implications to Worker Classification and Occupational Exposure Monitoring.

    PubMed

    Kortesniemi, Mika; Siiskonen, Teemu; Kelaranta, Anna; Lappalainen, Kimmo

    2016-04-21

    Radiation worker categorization and exposure monitoring are principal functions of occupational radiation safety. The aim of this study was to use the actual occupational exposure data in a large university hospital to estimate the frequency and magnitude of potential exposures in radiology. The additional aim was to propose a revised categorization and exposure monitoring practice based on the potential exposures. The cumulative probability distribution was calculated from the normalized integral of the probability density function fitted to the exposure data. Conformity of the probabilistic model was checked against 16 years of national monitoring data. The estimated probabilities to exceed annual effective dose limits of 1 mSv, 6 mSv and 20 mSv were 1:1000, 1:20 000 and 1:200 000, respectively. Thus, it is very unlikely that the class A categorization limit of 6 mSv could be exceeded, even in interventional procedures, with modern equipment and appropriate working methods. Therefore, all workers in diagnostic and interventional radiology could be systematically categorized into class B. Furthermore, current personal monitoring practice could be replaced by use of active personal dosemeters that offer more effective and flexible means to optimize working methods.

  1. Cumulative antibiotic exposures over time and the risk of Clostridium difficile infection.

    PubMed

    Stevens, Vanessa; Dumyati, Ghinwa; Fine, Lynn S; Fisher, Susan G; van Wijngaarden, Edwin

    2011-07-01

    Clostridium difficile infection (CDI) is a major cause of hospital-acquired diarrhea and is most commonly associated with changes in normal intestinal flora caused by administration of antibiotics. Few studies have examined the risk of CDI associated with total dose, duration, or number of antibiotics while taking into account the complex changes in exposures over time. A retrospective cohort study conducted from 1 January to 31 December 2005 among hospitalized patients 18 years or older receiving 2 or more days of antibiotics. The study identified 10,154 hospitalizations for 7,792 unique patients and 241 cases of CDI, defined as the detection of C. difficile toxin in a diarrheal stool sample within 60 days of discharge. We observed dose-dependent increases in the risk of CDI associated with increasing cumulative dose, number of antibiotics, and days of antibiotic exposure. Compared to patients who received only 1 antibiotic, the adjusted hazard ratios (HRs) for those who received 2, 3 or 4, or 5 or more antibiotics were 2.5 (95% confidence interval [CI] 1.6-4.0), 3.3 (CI 2.2-5.2), and 9.6 (CI 6.1-15.1), respectively. The receipt of fluoroquinolones was associated with an increased risk of CDI, while metronidazole was associated with reduced risk. Cumulative antibiotic exposures appear to be associated with the risk of CDI. Antimicrobial stewardship programs that focus on the overall reduction of total dose as well as number and days of antibiotic exposure and the substitution of high-risk antibiotic classes for lower-risk alternatives may reduce the incidence of hospital-acquired CDI. © The Author 2011. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved.

  2. Retrospective study of cumulative diagnostic radiation exposure during childhood in patients with spina bifida.

    PubMed

    Smookler, Gregory; Deavenport-Saman, Alexis

    2015-10-01

    The Biological Effects of Ionizing Radiation Committee of the National Academy of Sciences in 2005 and other expert panels have warned that risk of cancer increases with higher doses of radiation. Children with spina bifida and hydrocephalus have far greater exposure to radiation than the average person, starting almost directly after birth and continuing throughout their lifetimes. The purpose of this study was to estimate the amount of ionizing radiation that patients with spina bifida and hydrocephalus are exposed to during childhood from diagnostic imaging. Thirty patients, ages 18 years or older, with spina bifida and hydrocephalus were randomly selected from a spina bifida clinic and their radiology records were reviewed. Descriptive analyses were conducted. The total radiation exposure was then calculated for the study group, and the mean effective dose per patient was determined. In the study group, during their first 18 years, each patient had a mean of 55.1 studies and a median of 45 radiologic studies, a mean of 9.6 brain CT scans, and a mean cumulative effective dose of 81.9 mSv (2.6 mSv/patient/year over 18 years) and a median cumulative effective dose of 77.2 mSV of accumulated radiation exposure (4.5 mSv/patient/year over 18 years). Clinicians should recognize that increased radiation exposure puts patients with spina bifida and hydrocephalus at higher risk for cancer. The population of children and adults with spina bifida and hydrocephalus should be surveyed for incidence of cancer. Copyright © 2015 Elsevier Inc. All rights reserved.

  3. Cumulative systolic blood pressure exposure in relation to cognitive function in middle-aged and elderly adults

    PubMed Central

    Liu, Jie; Huang, Yuling; Chen, Guojuan; Liu, Xiaoxue; Wang, Zhijun; Cao, Yibin; Li, Haitao; Song, Lu; Li, Chunhui; Zhao, Hualing; Chen, Shuohua; Wang, Yiming; Zhang, Ruiying; Wang, Anxin; Wu, Shouling

    2016-01-01

    Abstract The association between systolic blood pressure (SBP) and cognitive function is controversial in elderly adults. In addition, few studies focused on the cumulative effect of SBP. We aimed to investigate the association between cumulative SBP exposure and cognitive function among middle-aged and elderly adults. The analysis was based on the Asymptomatic Polyvascular Abnormalities Community (APAC) study. The primary predictor was the cumulative SBP calculated by consecutive SBP values measured through baseline (2006–2007) up to the fourth examination (2012–2013). The cognitive function was estimated by mini-mental state examination (MMSE) in the fourth examination. Linear regression and logistic regression analyses were used to investigate the association between cumulative SBP and cognitive function. Among 2211 participants (41.4% female, aged 40–94 years), 167 (7.55%) were diagnosed with cognitive impairment (MMSE score < 24). Higher cumulative exposure to SBP (per SD increment) was independently associated with poor cognitive performance after controlling for multiple factors (P < 0.001). We observed nondifferential association between men and women. However, higher cumulative SBP in the adults aged ≥60 years had a stronger association with poor cognitive performance compared with that in adults aged 40 to 60 years. Greater exposure to cumulative SBP is associated with worse cognitive performance among middle-aged and elderly adults. This association is similar between men and women, but stronger in elderly adults. PMID:27902618

  4. Exposure to lead exacerbates dental fluorosis.

    PubMed

    Leite, G A S; Sawan, R M M; Teófilo, J M; Porto, I M; Sousa, F B; Gerlach, R F

    2011-07-01

    Our aim was to test the hypothesis that co-exposure to lead and fluoride alter the severity of enamel fluorosis. Wistar rats were allocated in four groups: control, and 3 groups that received water containing 100 ppm of fluoride (F), 30 ppm of lead (Pb), or 100 ppm of F and 30 ppm of Pb (F+Pb) from the beginning of gestation. Enamel analysis and F and Pb determinations in enamel, dentine, and bone were performed in 81-day-old animals. Fluorosis was quantified using a new fluorosis index based on the identification of incisor enamel defects (white bands and white islets, representing hypomineralization, and cavities) weighted according to their severity and quantity. Hypomineralization was validated histopathologically by polarizing microscopy and microradiography. Scores were given by two blinded calibrated examiners (intra and interexaminer kappa values were 0.8 and 0.86, respectively). The control and the Pb groups presented normal enamel. The F+Pb group presented more severe enamel defects compared with the F group (P<0.0001). This study shows that lead exacerbates dental fluorosis in rodents, suggesting that co-exposure to lead may affect the degree of fluorosis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. The Australian Work Exposures Study: Occupational Exposure to Lead and Lead Compounds.

    PubMed

    Driscoll, Timothy R; Carey, Renee N; Peters, Susan; Glass, Deborah C; Benke, Geza; Reid, Alison; Fritschi, Lin

    2016-01-01

    The aims of this study were to produce a population-based estimate of the prevalence of work-related exposure to lead and its compounds, to identify the main circumstances of exposures, and to collect information on the use of workplace control measures designed to decrease those exposures. Data came from the Australian Workplace Exposures Study, a nationwide telephone survey which investigated the current prevalence and circumstances of work-related exposure to 38 known or suspected carcinogens, including lead, among Australian workers aged 18-65 years. Using the web-based tool, OccIDEAS, semi-quantitative information was collected about exposures in the current job held by the respondent. Questions were addressed primarily at tasks undertaken rather than about self-reported exposures. A total of 307 (6.1%) of the 4993 included respondents were identified as probably being exposed to lead in the course of their work. Of these, almost all (96%) were male; about half worked in trades and technician-related occupations, and about half worked in the construction industry. The main tasks associated with probable exposures were, in decreasing order: soldering; sanding and burning off paint while painting old houses, ships, or bridges; plumbing work; cleaning up or sifting through the remains of a fire; radiator-repair work; machining metals or alloys containing lead; mining; welding leaded steel; and working at or using indoor firing ranges. Where information on control measures was available, inconsistent use was reported. Applied to the Australian working population, approximately 6.3% [95% confidence interval (CI) = 5.6-7.0] of all workers (i.e. 631000, 95% CI 566000-704000 workers) were estimated to have probable occupational exposure to lead. Lead remains an important exposure in many different occupational circumstances in Australia and probably other developed countries. This information can be used to support decisions on priorities for intervention and control

  6. Cumulative toxicity of neonicotinoid insecticide mixtures to Chironomus dilutus under acute exposure scenarios.

    PubMed

    Maloney, Erin M; Morrissey, Christy A; Headley, John V; Peru, Kerry M; Liber, Karsten

    2017-06-21

    Extensive agricultural use of neonicotinoid insecticide products has resulted in the presence of neonicotinoid mixtures in surface waters worldwide. Although many aquatic insect species are known to be sensitive to neonicotinoids, the impact of neonicotinoid mixtures is poorly understood. In the present study, the cumulative toxicities of binary and ternary mixtures of select neonicotinoids (imidacloprid, clothianidin, and thiamethoxam) were characterized under acute (96-h) exposure scenarios using the larval midge Chironomus dilutus as a representative aquatic insect species. Using the MIXTOX approach, predictive parametric models were fitted and statistically compared with observed toxicity in subsequent mixture tests. Single-compound toxicity tests yielded median lethal concentration (LC50) values of 4.63, 5.93, and 55.34 μg/L for imidacloprid, clothianidin, and thiamethoxam, respectively. Because of the similar modes of action of neonicotinoids, concentration-additive cumulative mixture toxicity was the predicted model. However, we found that imidacloprid-clothianidin mixtures demonstrated response-additive dose-level-dependent synergism, clothianidin-thiamethoxam mixtures demonstrated concentration-additive synergism, and imidacloprid-thiamethoxam mixtures demonstrated response-additive dose-ratio-dependent synergism, with toxicity shifting from antagonism to synergism as the relative concentration of thiamethoxam increased. Imidacloprid-clothianidin-thiamethoxam ternary mixtures demonstrated response-additive synergism. These results indicate that, under acute exposure scenarios, the toxicity of neonicotinoid mixtures to C. dilutus cannot be predicted using the common assumption of additive joint activity. Indeed, the overarching trend of synergistic deviation emphasizes the need for further research into the ecotoxicological effects of neonicotinoid insecticide mixtures in field settings, the development of better toxicity models for neonicotinoid mixture

  7. Monitoring wild bird populations for lead exposure

    SciTech Connect

    Scheuhammer, A.M. )

    1989-07-01

    Delta-aminolevulinic acid dehydratase (ALA-d), an enzyme in the heme biosynthetic pathway is extremely sensitive to inhibition by lead (Pb). I evaluated the erythrocyte ALA-d activity ratio (the ratio between the fully restored enzyme activity and that measured without removing any inhibitory influence that might be present) as an indicator of Pb exposure in free-living birds. In the absence of elevated Pb exposure, birds, had comparable ALA-d activity ratios regardless of species, geographical location, or time of year sampled. The normal range of ratios for free-living species was similar to that for aviary-raised birds (1.0-1.3). Individuals with enzyme inhibition were readily identified. In blood collected from free-living mallards (Anas platyrhynchos), ALA-d activity ratios were better correlated with blood-Pb than were blood-protoporphyrin (PP) concentrations. At least 9.5% of mallards with blood-Pb>80 {mu}g/dL did not have elevated PP levels. Underestimation of Pb exposure did not occur using the ALA-d activity ratio method. The ALA-d activity ratio was as accurate as blood-Pb measurements for monitoring the relative degree of recent Pb exposure in the wild bird populations studied. Unlike blood-Pb analyses, ALA-d determinations do not require exposure in the wild bird populations studied. Unlike blood-Pb analyses, ALA-d determinations do not require exposure in the wild bird populations studied. Unlike blood-Pb analyses, ALA-d determinations do not require sophisticated and expensive instrumentation, and assays can be performed efficiently with minimal training.

  8. Assessing the Role of Current and "Cumulative" Exposure in Simultaneous Bilingual Acquisition: The Case of Dutch Gender

    ERIC Educational Resources Information Center

    Unsworth, Sharon

    2013-01-01

    This paper investigates the role of amount of current and "cumulative" exposure in bilingual development and ultimate attainment by exploring the extent to which simultaneous bilingual children's knowledge of grammatical gender is affected by current and previous amount of exposure, including in the early years. Elicited production and…

  9. Cumulative Risk Assessment: An Overview of Methodological Approaches for Evaluating Combined Health Effects from Exposure to Multiple Environmental Stressors

    PubMed Central

    Sexton, Ken

    2012-01-01

    Systematic evaluation of cumulative health risks from the combined effects of multiple environmental stressors is becoming a vital component of risk-based decisions aimed at protecting human populations and communities. This article briefly examines the historical development of cumulative risk assessment as an analytical tool, and discusses current approaches for evaluating cumulative health effects from exposure to both chemical mixtures and combinations of chemical and nonchemical stressors. A comparison of stressor-based and effects-based assessment methods is presented, and the potential value of focusing on viable risk management options to limit the scope of cumulative evaluations is discussed. The ultimate goal of cumulative risk assessment is to provide answers to decision-relevant questions based on organized scientific analysis; even if the answers, at least for the time being, are inexact and uncertain. PMID:22470298

  10. Assessing Cumulative Thermal Stress in Fish During Chronic Exposure to High Temperature

    SciTech Connect

    Bevelhimer, M.S.; Bennett, W.R.

    1999-11-14

    As environmental laws become increasingly protective, and with possible future changes in global climate, thermal effects on aquatic resources are likely to receive increasing attention. Lethal temperatures for a variety of species have been determined for situations where temperatures rise rapidly resulting in lethal effects. However, less is known about the effects of chronic exposure to high (but not immediately lethal) temperatures and even less about stress accumulation during periods of fluctuating temperatures. In this paper we present a modeling framework for assessing cumulative thermal stress in fish. The model assumes that stress accumulation occurs above a threshold temperature at a rate depending on the degree to which the threshold is exceeded. The model also includes stress recovery (or alleviation) when temperatures drop below the threshold temperature as in systems with large daily variation. In addition to non-specific physiological stress, the model also simulates thermal effects on growth.

  11. Cumulative Violence Exposures: Black Women’s Responses and Sources of Strength

    PubMed Central

    Sabri, Bushra; Holliday, Charvonne N.; Alexander, Kamila A.; Huerta, Julia; Cimino, Andrea; Callwood, Gloria B.; Campbell, Jacquelyn C.

    2016-01-01

    Black women with cumulative violence exposures (CVE) may have unique needs for health care and safety. Qualitative data was analyzed from interviews with nine Black women with CVE to explore factors that motivated women to leave abusive relationships, women’s sources of strengths, and their responses to abuse. Quantitative data (N = 163) was analyzed to examine relationships between CVEs by intimate partner and health among Black women to further characterize the challenges these women face in making changes and finding their sources of strengths. Findings highlight the need to assess for CVE and identify multiple motivators for change, sources of strengths and coping strategies that could be potential points of intervention for women with CVE. PMID:26954765

  12. Epigenome: A Biomarker or Screening Tool to Evaluate Health Impact of Cumulative Exposure to Chemical and Non-Chemical Stressors

    PubMed Central

    Olden, Kenneth; Lin, Yu-Sheng; Bussard, David

    2016-01-01

    Current risk assessment practices and toxicity information are hard to utilize for assessing the health impact of combined or cumulative exposure to multiple chemical and non-chemical stressors encountered in the “real world” environment. Non-chemical stressors such as heat, radiation, noise, humidity, bacterial and viral agents, and social factors, like stress related to violence and socioeconomic position generally cannot be currently incorporated into the risk assessment paradigm. The Science and Decisions report released by the National Research Council (NRC) in 2009 emphasized the need to characterize the effects of multiple stressors, both chemical and non-chemical exposures. One impediment to developing information relating such non-chemical stressors to health effects and incorporating them into cumulative assessment has been the lack of analytical tools to easily and quantitatively monitor the cumulative exposure to combined effects of stressors over the life course.

  13. How to quantify exposure to traumatic stress? Reliability and predictive validity of measures for cumulative trauma exposure in a post-conflict population

    PubMed Central

    Wilker, Sarah; Pfeiffer, Anett; Kolassa, Stephan; Koslowski, Daniela; Elbert, Thomas; Kolassa, Iris-Tatjana

    2015-01-01

    Background While studies with survivors of single traumatic experiences highlight individual response variation following trauma, research from conflict regions shows that almost everyone develops posttraumatic stress disorder (PTSD) if trauma exposure reaches extreme levels. Therefore, evaluating the effects of cumulative trauma exposure is of utmost importance in studies investigating risk factors for PTSD. Yet, little research has been devoted to evaluate how this important environmental risk factor can be best quantified. Methods We investigated the retest reliability and predictive validity of different trauma measures in a sample of 227 Ugandan rebel war survivors. Trauma exposure was modeled as the number of traumatic event types experienced or as a score considering traumatic event frequencies. In addition, we investigated whether age at trauma exposure can be reliably measured and improves PTSD risk prediction. Results All trauma measures showed good reliability. While prediction of lifetime PTSD was most accurate from the number of different traumatic event types experienced, inclusion of event frequencies slightly improved the prediction of current PTSD. Conclusions As assessing the number of traumatic events experienced is the least stressful and time-consuming assessment and leads to the best prediction of lifetime PTSD, we recommend this measure for research on PTSD etiology. PMID:26589255

  14. Cumulative and episodic vaccine aluminum exposure in a population-based cohort of young children.

    PubMed

    Glanz, Jason M; Newcomer, Sophia R; Daley, Matthew F; McClure, David L; Baxter, Roger P; Jackson, Michael L; Naleway, Allison L; Lugg, Marlene M; DeStefano, Frank

    2015-11-27

    In addition to antigens, vaccines contain small amounts of preservatives, adjuvants, and residual substances from the manufacturing process. Some parents have concerns about the safety of these ingredients, yet no large epidemiological studies have specifically examined associations between health outcomes and vaccine ingredients, other than thimerosal. This study examined the extent to which the Vaccine Safety Datalink (VSD) could be used to study vaccine ingredient safety in children. Children born 2004-2011 were identified in VSD data. Using immunization records, two cohorts were identified: children who were up-to-date and children who were undervaccinated before age 2 years. A database was also created linking vaccine type and manufacturer with ingredient amounts documented in vaccine package inserts. Thirty-four ingredients in two or more infant vaccines were identified. However, only amounts (in mg) for aluminum were consistently documented and commonly contained in infant vaccines. Analyses compared vaccine aluminum exposure across cohorts and determined the statistical power for studying associations between aluminum exposure and hypothetical vaccine adverse events. Among 408,608 children, mean cumulative vaccine aluminum exposure increased from 1.11 to 4.00 mg between ages 92-730 days. Up-to-date children were exposed to 11-26% more aluminum from vaccines than undervaccinated children. Power analyses demonstrated that safety studies of aluminum could detect relative risks ranging from 1.1 to 5.8 for a range of adverse event incidence. The safety of vaccine aluminum exposure can be feasibly studied in the VSD. However, possible biological mechanisms and confounding variables would need to be considered before conducting any studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Cumulative Radiation Exposure With EOS Imaging Compared With Standard Spine Radiographs.

    PubMed

    Luo, T David; Stans, Anthony A; Schueler, Beth A; Larson, A Noelle

    2015-03-01

    Retrospective comparative study. This study sought to estimate the total radiation exposure to scoliosis patients during the entire treatment course using standard imaging techniques versus EOS posteroanterior (PA) and anteroposterior (AP) views. EOS is a slot-scanning X-ray system designed to reduce radiation exposure in orthopedic imaging. There are few independent studies comparing organ and total effective radiation dose from standard EOS PA, AP, and lateral imaging versus conventional projection radiographs for children with spinal deformity. A total of 42 skeletally immature idiopathic scoliosis patients were treated with bracing (21) or spinal fusion (21) and were followed to skeletal maturity. The number of scoliosis radiographs (PA and lateral) for each patient was recorded. A computerized dosing model was used to calculate estimated patient and organ doses for PA and lateral scoliosis X-rays taken with EOS or computed radiography with a filter (CR) or without a filter (CRF). Assuming that each X-ray taken delivered the same radiation as the phantom calculation, the authors estimated the total effective and organ dose that each adolescent would have received using EOS, CR, or CRF. Annual background radiation is 3 mSv. Mean number of radiographs per patient was 20.9 (range, 8-43). Patients who underwent surgical treatment had a significantly greater number of X-rays than those who were braced (27.3 vs. 14.5; p < .001). Assuming all films were CR, the mean cumulative dose was estimated at 5.38 mSv. With standard EOS films, the mean cumulative estimated dose was 2.66 mSv, a decrease of 50.6%. An AP versus PA EOS radiograph resulted in an 8 times higher radiation dose to the breasts and 4 times higher dose to the thyroid. The standard EOS imaging system moderately reduced the total radiation exposure to skeletally immature scoliosis patients. Over the entire treatment course, this represented 2.72 mSv mean reduction or 0.91 years of background radiation

  16. Anxiety and depression following cumulative low-level exposure to organophosphate pesticides.

    PubMed

    Harrison, Virginia; Mackenzie Ross, Sarah

    2016-11-01

    Previous research suggests that individuals with a prior history of pesticide poisoning are at increased risk of psychiatric disorder (Freire and Koifman, 2013), but findings regarding the impact of cumulative low-level exposure are inconsistent. The aim of the current study was to investigate whether sheep farmers with a history of low-level exposure to organophosphate pesticides (1) report a higher level of psychological distress on subjective symptom questionnaires, compared to unexposed controls (2) also meet internationally agreed diagnostic criteria for a psychiatric disorder more often than unexposed controls. 127sheep farmers were evaluated and compared to 78 unexposed controls, matched in terms of gender, education, level of intelligence, working status and area of residence. Both self-report measures and structured clinical interviews were used to assess mental health. The exposed cohort reported significantly higher rates of anxiety and depression when self-report questionnaires were used to evaluate mood, even when stressful life events, demographic and physical health factors were taken into account. However, when diagnostic interviews were used to assess mood, this pattern only held true for anxiety. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Impact of smoking status and cumulative smoking exposure on tumor recurrence of non-muscle-invasive bladder cancer.

    PubMed

    Li, Hao Min; Azhati, Baihetiya; Rexiati, Mulati; Wang, Wen Guang; Li, Xiao Dong; Liu, Qiang; Wang, Yu-Jie

    2017-01-01

    To investigate the effect of smoking status, cumulative smoking exposure and smoking cessation on the outcomes of patient with non-muscle-invasive bladder cancer (NMIBC). We collected smoking data from 484 patients with NMIBC who were treated with transurethral resection (TUR); smoking status was categorized as (never smokers vs current smokers vs former smokers). Cumulative smoking exposure was categorized as high smoking exposure (cigarette index ≥400) versus low smoking exposure (cigarette index <400). Association with outcomes was examined by multivariable analyses after adjusting for the effects of standard clinicopathologic factors, and the Kaplan-Meier method was used to estimate the effect of smoking status and cumulative smoking exposure on RFS. A total of 168 (34.7 %) patients were never smoker, 121 (25 %) patients were current smokers, and 195 (40.3 %) patients were former smokers. The median follow-up was 25 months. By multivariate analysis, pathological grade (p = 0.013), history of recurrence (p < 0.001), number of tumors (p < 0.001) and size of tumors (p = 0.013) were significantly associated with tumor recurrence; nevertheless, smoking status did not influence tumor recurrence (p = 0.063). Among current and former smokers, cumulative smoking exposure was significantly associated with tumor recurrence (p < 0.001), compared to current smokers, patients with smoking cessation ≥10 years had a lower risk of tumor recurrence [hazard ratio (HR) 0.456, p = 0.007]. Smoking affects the prognosis of patient with NMIBC, which is still controversial; however, among ever smokers, a high cumulative exposure smoking can significantly increase the risk of tumor recurrence. Quitting smoking might be associated with a lower recurrence rate for patients with NMIBC.

  18. Cumulative Exposure Assessment for Trace-Level Polycyclic Aromatic Hydrocarbons (PAHs) using Human Blood and Plasma Analysis

    EPA Science Inventory

    Humans experience chronic cumulative trace-level exposure to mixtures of volatile, semi-volatile, and non-volatile polycyclic aromatic hydrocarbons (PAHs) present in the environment as by-products of combustion processes. Certain PAHs are known or suspected human carcinogens and ...

  19. Cumulative Risk Exposure and Mental Health Symptoms among Maltreated Youth Placed in Out-of-Home Care

    ERIC Educational Resources Information Center

    Raviv, Tali; Taussig, Heather N.; Culhane, Sara E.; Garrido, Edward F.

    2010-01-01

    Objective: Maltreated children placed in out-of-home care are at high risk for exhibiting symptoms of psychopathology by virtue of their exposure to numerous risk factors. Research examining cumulative risk has consistently found that the accumulation of risk factors increases the likelihood of mental health problems. The goal of the current study…

  20. Cumulative Exposure Assessment for Trace-Level Polycyclic Aromatic Hydrocarbons (PAHs) using Human Blood and Plasma Analysis

    EPA Science Inventory

    Humans experience chronic cumulative trace-level exposure to mixtures of volatile, semi-volatile, and non-volatile polycyclic aromatic hydrocarbons (PAHs) present in the environment as by-products of combustion processes. Certain PAHs are known or suspected human carcinogens and ...

  1. Cumulative Risk Exposure and Mental Health Symptoms among Maltreated Youth Placed in Out-of-Home Care

    ERIC Educational Resources Information Center

    Raviv, Tali; Taussig, Heather N.; Culhane, Sara E.; Garrido, Edward F.

    2010-01-01

    Objective: Maltreated children placed in out-of-home care are at high risk for exhibiting symptoms of psychopathology by virtue of their exposure to numerous risk factors. Research examining cumulative risk has consistently found that the accumulation of risk factors increases the likelihood of mental health problems. The goal of the current study…

  2. SOURCES AND PATHWAYS OF LEAD EXPOSURE

    EPA Science Inventory

    Exposure is defined here as the amount of a substance that comes into contact with an absorbing surface during a specified period of time. The normal units of exposure are expressed as micrograms per day. The two components of exposure are the concentration of the substance in ...

  3. SOURCES AND PATHWAYS OF LEAD EXPOSURE

    EPA Science Inventory

    Exposure is defined here as the amount of a substance that comes into contact with an absorbing surface during a specified period of time. The normal units of exposure are expressed as micrograms per day. The two components of exposure are the concentration of the substance in ...

  4. Do Multiple Concussions Lead to Cumulative Cognitive Deficits? A Literature Review.

    PubMed

    Yumul, Joy Noelle; McKinlay, Audrey

    2016-11-01

    A concussion is an important health concern for children and adolescents, particularly in the context of sporting injuries. Some research suggests a cumulative effect from multiple concussions (also referred to as mild traumatic brain injury), which creates a dilemma when considering how to manage children and young persons who may experience multiple concussive events within a sporting season. However, there is very little research regarding the outcomes of multiple concussions and their optimal management. The purpose of this review is to evaluate the evidence regarding the cognitive outcomes of multiple concussions. After assessing the eligibility of the articles from the literature search, 7 studies were identified and included in the review. In most of the available literature, the cognitive outcomes related to multiple concussions are measured during the same developmental age as when the injuries happened. Moreover, most studies that investigated multiple concussions are focused on sports-related injuries, and only some are conducted in children and adolescents in the general population. The current evidence is inconclusive; whereas some studies reported adverse outcomes, others reported null findings. The studies that reported adverse or cumulative effects based their findings on worse cognitive outcomes, more subjective symptoms, and prolonged recovery postinjury. II. Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

  5. Cumulative radiation exposure from diagnostic imaging in intensive care unit patients

    PubMed Central

    Moloney, Fiachra; Fama, Daniel; Twomey, Maria; O’Leary, Ruth; Houlihane, Conor; Murphy, Kevin P; O’Neill, Siobhan B; O’Connor, Owen J; Breen, Dorothy; Maher, Michael M

    2016-01-01

    AIM: To quantify cumulative effective dose of intensive care unit (ICU) patients attributable to diagnostic imaging. METHODS: This was a prospective, interdisciplinary study conducted in the ICU of a large tertiary referral and level 1 trauma center. Demographic and clinical data including age, gender, date of ICU admission, primary reason for ICU admission, APACHE II score, length of stay, number of days intubated, date of death or discharge, and re-admission data was collected on all patients admitted over a 1-year period. The overall radiation exposure was quantified by the cumulative effective radiation dose (CED) in millisieverts (mSv) and calculated using reference effective doses published by the United Kingdom National Radiation Protection Board. Pediatric patients were selected for subgroup-analysis. RESULTS: A total of 2737 studies were performed in 421 patients. The total CED was 1704 mSv with a median CED of 1.5 mSv (IQR 0.04-6.6 mSv). Total CED in pediatric patients was 74.6 mSv with a median CED of 0.07 mSv (IQR 0.01-4.7 mSv). Chest radiography was the most commonly performed examination accounting for 83% of all studies but only 2.7% of total CED. Computed tomography (CT) accounted for 16% of all studies performed and contributed 97% of total CED. Trauma patients received a statistically significant higher dose [median CED 7.7 mSv (IQR 3.5-13.8 mSv)] than medical [median CED 1.4 mSv (IQR 0.05-5.4 mSv)] and surgical [median CED 1.6 mSv (IQR 0.04-7.5 mSv)] patients. Length of stay in ICU [OR = 1.12 (95%CI: 1.079-1.157)] was identified as an independent predictor of receiving a CED greater than 15 mSv. CONCLUSION: Trauma patients and patients with extended ICU admission times are at increased risk of higher CEDs. CED should be minimized where feasible, especially in young patients. PMID:27158429

  6. Lead exposure in US worksites: A literature review and development of an occupational lead exposure database from the published literature

    PubMed Central

    Koh, Dong-Hee; Locke, Sarah J.; Chen, Yu-Cheng; Purdue, Mark P.; Friesen, Melissa C.

    2016-01-01

    Background Retrospective exposure assessment of occupational lead exposure in population-based studies requires historical exposure information from many occupations and industries. Methods We reviewed published US exposure monitoring studies to identify lead exposure measurement data. We developed an occupational lead exposure database from the 175 identified papers containing 1,111 sets of lead concentration summary statistics (21% area air, 47% personal air, 32% blood). We also extracted ancillary exposure-related information, including job, industry, task/location, year collected, sampling strategy, control measures in place, and sampling and analytical methods. Results Measurements were published between 1940 and 2010 and represented 27 2-digit standardized industry classification codes. The majority of the measurements were related to lead-based paint work, joining or cutting metal using heat, primary and secondary metal manufacturing, and lead acid battery manufacturing. Conclusions This database can be used in future statistical analyses to characterize differences in lead exposure across time, jobs, and industries. PMID:25968240

  7. Biological tests of lead absorption following a brief massive exposure

    SciTech Connect

    Williams, M.K.

    1984-07-01

    A contractor's man suffered a brief, massive exposure to lead fume by contaminating and then smoking hand-rolled cigarettes. His blood lead concentration rose very rapidly to very high levels, but zinc erythrocyte protoporphyrin, urinary lead, and urinary coproporphyrin did not. It is possible that only the blood lead concentration is of value in detecting brief massive exposure.

  8. Testing a cumulative and aggregate exposure model using biomonitoring studies and dietary records for Italian vineyard spray operators.

    PubMed

    Kennedy, Marc C; Glass, C Richard; Fustinoni, Silvia; Moretto, Angelo; Mandic-Rajcevic, Stefan; Riso, Patrizia; Turrini, Aida; van der Voet, Hilko; Hetmanski, Michel T; Fussell, Richard J; van Klaveren, Jacob D

    2015-05-01

    The need for improved tools to estimate the cumulative and aggregate exposure to compounds such as plant protection products (PPPs) is recognised in the EU Regulation 1107/2009. A new model has been developed to estimate the exposure within a population to single compounds or compounds within a Cumulative Action Group, considering dietary and non-dietary sources and multiple exposure routes. To test the model a field study was carried out in Italy with operators applying tebuconazole fungicides, with measurements of dermal exposure collected. Whole urine samples were collected and analysed to provide values for the absorbed dose of tebuconazole, with duplicate diet samples collected and analysed as a measure of dietary exposures. The model provided predicted values of exposure for combined dietary and non-dietary routes of exposures which were compared to the measured absorbed dose values based on urinary analysis. The model outputs provided mean daily exposure values of 1.77 (± 1.96) µg a.s./kg BW which are comparable to measured mean values from the biomonitoring field study of 1.73 (± 1.31) µg a.s./kg BW. To supplement the limited measurement data available, comparisons against other models were also made and found to be comparable.

  9. Associations of cumulative Pb exposure and longitudinal changes in Mini-Mental Status Exam scores, global cognition and domains of cognition: The VA Normative Aging Study.

    PubMed

    Farooqui, Zishaan; Bakulski, Kelly M; Power, Melinda C; Weisskopf, Marc G; Sparrow, David; Spiro, Avron; Vokonas, Pantel S; Nie, Linda H; Hu, Howard; Park, Sung Kyun

    2017-01-01

    Lead (Pb) exposure has been associated with poorer cognitive function cross-sectionally in aging adults, however the association between cumulative Pb exposure and longitudinal changes in cognition is little characterized. In a 1993-2007 subcohort of the VA Normative Aging Study (Mini-mental status exam (MMSE) n=741; global cognition summary score n=715), we used linear mixed effects models to test associations between cumulative Pb exposure (patella or tibia bone Pb) and repeated measures of cognition (MMSE, individual cognitive tests, and global cognition summary). Cox proportional hazard modeling assessed the risk of an MMSE score falling below 25. Among men 51-98 at baseline, higher patella Pb concentration (IQR: 21μg/g) was associated with -0.13 lower baseline MMSE (95% CI: -0.25, -0.004) and faster longitudinal MMSE decline (-0.016 units/year, 95% CI: -0.032, -0.0004) over 15 years. Each IQR increase in patella Pb was associated with increased risk of a MMSE score below 25 (HR=1.21, 95% CI: 0.99, 1.49; p=0.07). There were no significant associations between Pb and global cognition (both baseline and longitudinal change). Patella Pb was associated with faster longitudinal decline in Word List Total Recall in the language domain (0.014 units/year, 95% CI: -0.026, -0.001) and Word List Delayed Recall in the memory domain (0.014 units/year, 95% CI: -0.027, -0.002). We found weaker associations with tibia Pb. Cumulative Pb exposure is associated with faster declines in MMSE and Word List Total and Delayed Recall tests. These findings support the hypothesis that Pb exposure accelerates cognitive aging. Copyright © 2016 Elsevier Inc. All rights reserved.

  10. Mortality and Cumulative Exposure to Antipsychotics, Antidepressants, and Benzodiazepines in Patients With Schizophrenia: An Observational Follow-Up Study.

    PubMed

    Tiihonen, Jari; Mittendorfer-Rutz, Ellenor; Torniainen, Minna; Alexanderson, Kristina; Tanskanen, Antti

    2016-06-01

    Although mortality related to psychotropic medications has received much attention in recent years, little is known about the relationship between risk of death and cumulative antipsychotic load, and even less about the relationship between mortality and cumulative exposure to antidepressants or benzodiazepines. The authors examined these relationships using nationwide databases. The authors used prospectively collected nationwide databases to identify all individuals 16-65 years of age with a schizophrenia diagnosis (N=21,492) in Sweden. All-cause and cause-specific mortality rates were calculated as a function of cumulative low, moderate, and high exposure to antipsychotics, antidepressants, and benzodiazepines from 2006 through 2010. Compared with no exposure, both moderate (adjusted hazard ratio=0.59, 95% CI=0.49-0.70) and high (adjusted hazard ratio=0.75, 95% CI=0.63-0.89) antipsychotic exposures were associated with substantially lower overall mortality. Moderate antidepressant exposure was associated with a lower mortality (adjusted hazard ratio=0.85, 95% CI=0.73-0.98), and high exposure, even lower (adjusted hazard ratio=0.71, 95% CI=0.59-0.86). Exposure to benzodiazepines showed a dose-response relationship with mortality (hazard ratios up to 1.74 [95% CI=1.50-2.03]). Moderate and high-dose antipsychotic and antidepressant use were associated with 15%-40% lower overall mortality, whereas chronic high-dose use of benzodiazepines was associated with up to a 70% higher risk of death compared with no exposure. Since patients with anxiety and depressive symptoms may have a higher intrinsic risk of death, the finding for benzodiazepines may be attributable to some extent to residual confounding.

  11. Assessing the cumulative effects of exposure to selected benzodiazepines on the risk of fall-related injuries in the elderly.

    PubMed

    Sylvestre, Marie-Pierre; Abrahamowicz, Michal; Čapek, Radan; Tamblyn, Robyn

    2012-04-01

    The use of benzodiazepines is associated with increased risk of fall-related injuries in the elderly. However, it is unclear if the risks vary across the products and how they depend on the pattern of use and dosage. Specifically, the possibility of cumulative effects of past benzodiazepine use has not been thoroughly investigated. We used the administrative database for a cohort of 23,765 new users of benzodiazepines, aged 65 years and older, in Quebec, Canada, between 1990 and 1994. The associations between the use of seven benzodiazepines and the risk of fall-related injuries were assessed using several statistical models, including a novel weighted cumulative exposure model. That model assigns to each dose taken in the past a weight that represents the importance of that dose in explaining the current risk of fall. For flurazepam, the best-fitting model indicated a cumulative effect of doses taken in the last two weeks. Uninterrupted use of flurazepam in the past months was associated with a highly significant increase in the risk of fall-related injuries (HR = 2.83, 95% CI: 1.45-4.34). The cumulative effect of a 30-day exposure to alprazolam was 1.27 (1.13-1.42). For temazepam, the results suggested a potential withdrawal effect. Mechanisms affecting the risk of falls differ across benzodiazepines, and may include cumulative effects of use in the previous few weeks. Thus, benzodiazepine-specific analyses that account for individual patterns of use should be preferred over simpler analyses that group different benzodiazepines together and limit exposure to current use or current dose.

  12. Associations between silicone skin cast score, cumulative sun exposure, and other factors in the ausimmune study: a multicenter Australian study.

    PubMed

    Lucas, Robyn M; Ponsonby, Anne-Louise; Dear, Keith; Taylor, Bruce V; Dwyer, Terence; McMichael, Anthony J; Valery, Patricia; van der Mei, Ingrid; Williams, David; Pender, Michael P; Chapman, Caron; Coulthard, Alan; Kilpatrick, Trevor

    2009-11-01

    Past sun exposure is linked to a wide range of disease outcomes but is difficult to measure accurately. Silicone skin casts measure skin damage, but some studies show that age rather than sun exposure is the most important determinant of cast score. We examined skin damage scores from silicone casts of the back of the hand in a large adult sample (n = 534) with a broad range of past cumulative UV radiation (UVR) doses. Participants were ages 18 to 61 years and resided in one of four locations down the eastern Australian seaboard, spanning 27-43 degrees S. Data were collected by questionnaire and during a nurse-led interview and examination. Silicone casts were graded from 1 to 6, where higher score represents greater damage. Higher skin damage score was associated with lighter skin pigmentation [adjusted odds ratio (AOR), 4.51; 95% confidence interval (95% CI), 2.33-8.75], fairer natural hair color, particularly red hair (AOR, 11.31; 95% CI, 4.08-31.36), and blue/gray eyes (AOR, 1.72; 95% CI, 1.14-2.59). Higher cumulative UVR dose, particularly before age 18 years, was associated with higher skin damage score (AOR, 2.06; 95% CI, 1.15-2.67 per 1,000 KJ/m(2)), as was number of sunburns, even after adjustment for cumulative UVR dose (AOR, 2.86; 95% CI, 1.50-5.43 for >10 sunburns ever compared with no sunburns ever). Silicone casts of the dorsum of the hand provide a measure of cumulative UVR dose and number of sunburns over the lifetime, which persists after adjustment for chronological age. They can be used as an objective measure of cumulative past sun exposure in epidemiologic studies, but other determinants of skin damage, such as skin pigmentation, should be concurrently evaluated.

  13. Racial differences in Urban children's environmental exposures to lead.

    PubMed Central

    Lanphear, B P; Weitzman, M; Eberly, S

    1996-01-01

    OBJECTIVES: This study explored whether differences in environmental lead exposures explain the racial disparity in children's blood lead levels. METHODS: Environmental sources of lead were identified for a random sample of 172 urban children. RESULTS: Blood lead levels were significantly higher among Black children. Lead-contamination of dust was higher in Black children's homes, and the condition of floors and interior paint was generally poorer. White children were more likely to put soil in their mouths and to suck their fingers, whereas Black children were more likely to put their mouths on window sills and to use a bottle. Major contributors to blood lead were interior lead exposures for Black children and exterior lead exposures for White children. CONCLUSIONS: Differences in housing conditions and exposures to lead-contaminated house dust contribute strongly to the racial disparity in urban children's blood lead levels. PMID:8876521

  14. Lead exposure in Canada geese of the Eastern Prairie Population

    USGS Publications Warehouse

    DeStefano, S.; Brand, C.J.; Rusch, D.H.; Finley, Daniel L.; Gillespie, M.M.

    1991-01-01

    We monitored lead exposure in Eastern Prairie Population Canada geese during summer-winter, 1986-1987 and 1987-1988 at 5 areas. Blood lead concentrations in geese trapped during summer at Cape Churchill Manitoba were below levels indicative of recent lead exposure (0.18 ppm). Geese exposed to lead (≥0.18 ppm blood lead) increased to 7.6% at Oak Hammock Wildlife Management Area (WMA), southern Manitoba, where lead shot was still in use, and to 10.0% at Roseau River WMA, northern Minnesota, when fall-staging geese were close to a source of lead shot in Manitoba. Proportion of birds exposed to lead dropped to <2% at Lac Qui Parle WMA, Minnesota, a steel shot zone since 1980. On the wintering grounds at Swan Lake National Wildlife Refuge in Missouri, 4.9% of all geese showed exposure to lead before the hunting season. Lead exposure rose to 10.0% after hunting ended and then decreased to 5.2% in late winter. Incidence of lead shot in gizzards and concentrations of lead in livers supported blood assay data. Soil samples indicated that lead shot continues to be available to geese at Swan Lake, even though the area was established as a non-toxic shot zone in 1978. Steel shot zones have reduced lead exposure in the Eastern Prairie Population, but lead shot persists in the environment and continues to account for lead exposure and mortality in Eastern Prairie Population Canada geese.

  15. Lessons from a Danish study on neuropsychological impairment related to lead exposure

    SciTech Connect

    Grandjean, P.; Lyngbye, T. ); Hansen, O.N. )

    1991-08-01

    Serious problems emerge when evaluating evidence on lead neurotoxicity in children. The extent of these problems and ways to control them were explored in a study of 1291 children from the first class in the schools of Aarhus municipality, Denmark. The lead retention in circumpulpal dentin in shed deciduous teeth was used as an indicator of cumulated lead exposure; it correlated most strongly with traffic density at the residence of each family and at the day-care institutions. In a nested case-control group selected on the basis of dentin lead concentrations, 29 of 200 children had encountered obstetrical complications and other medical risks for neurobehavioral dysfunction; these children primarily belonged to the low-lead group. As lead-related neurobehavioral effects are nonspecific, inclusion of these children in the data analysis would therefore have distorted the results toward the null hypothesis. Children from the high-lead group who had experienced neonatal jaundice showed impaired performance when compared to other high-lead children; this finding may suggest a synergistic effect. The Bender gestalt test scored by the Goettingen system was the test that was most sensitive to lead exposure. The conclusion that neurobehavioral effects can be caused by the relatively low lead exposures in Denmark may not be surprising, as current exposures to this toxic metal greatly exceed the prepollution levels to which the human body originally adapted.

  16. Head Impact Exposure in Youth Football: High School Ages 14 to 18 Years and Cumulative Impact Analysis

    PubMed Central

    Urban, Jillian E.; Davenport, Elizabeth M.; Golman, Adam J.; Maldjian, Joseph A.; Whitlow, Christopher T.; Powers, Alexander K.; Stitzel, Joel D.

    2015-01-01

    Sports-related concussion is the most common athletic head injury with football having the highest rate among high school athletes. Traditionally, research on the biomechanics of football-related head impact has been focused at the collegiate level. Less research has been performed at the high school level, despite the incidence of concussion among high school football players. The objective of this study is to twofold: to quantify the head impact exposure in high school football, and to develop a cumulative impact analysis method. Head impact exposure was measured by instrumenting the helmets of 40 high school football players with helmet mounted accelerometer arrays to measure linear and rotational acceleration. A total of 16,502 head impacts were collected over the course of the season. Biomechanical data were analyzed by team and by player. The median impact for each player ranged from 15.2 to 27.0 g with an average value of 21.7 (±2.4) g. The 95th percentile impact for each player ranged from 38.8 to 72.9 g with an average value of 56.4 (±10.5) g. Next, an impact exposure metric utilizing concussion injury risk curves was created to quantify cumulative exposure for each participating player over the course of the season. Impacts were weighted according to the associated risk due to linear acceleration and rotational acceleration alone, as well as the combined probability (CP) of injury associated with both. These risks were summed over the course of a season to generate risk weighted cumulative exposure. The impact frequency was found to be greater during games compared to practices with an average number of impacts per session of 15.5 and 9.4, respectively. However, the median cumulative risk weighted exposure based on combined probability was found to be greater for practices vs. games. These data will provide a metric that may be used to better understand the cumulative effects of repetitive head impacts, injury mechanisms, and head impact exposure of

  17. Head impact exposure in youth football: high school ages 14 to 18 years and cumulative impact analysis.

    PubMed

    Urban, Jillian E; Davenport, Elizabeth M; Golman, Adam J; Maldjian, Joseph A; Whitlow, Christopher T; Powers, Alexander K; Stitzel, Joel D

    2013-12-01

    Sports-related concussion is the most common athletic head injury with football having the highest rate among high school athletes. Traditionally, research on the biomechanics of football-related head impact has been focused at the collegiate level. Less research has been performed at the high school level, despite the incidence of concussion among high school football players. The objective of this study is to twofold: to quantify the head impact exposure in high school football, and to develop a cumulative impact analysis method. Head impact exposure was measured by instrumenting the helmets of 40 high school football players with helmet mounted accelerometer arrays to measure linear and rotational acceleration. A total of 16,502 head impacts were collected over the course of the season. Biomechanical data were analyzed by team and by player. The median impact for each player ranged from 15.2 to 27.0 g with an average value of 21.7 (±2.4) g. The 95th percentile impact for each player ranged from 38.8 to 72.9 g with an average value of 56.4 (±10.5) g. Next, an impact exposure metric utilizing concussion injury risk curves was created to quantify cumulative exposure for each participating player over the course of the season. Impacts were weighted according to the associated risk due to linear acceleration and rotational acceleration alone, as well as the combined probability (CP) of injury associated with both. These risks were summed over the course of a season to generate risk weighted cumulative exposure. The impact frequency was found to be greater during games compared to practices with an average number of impacts per session of 15.5 and 9.4, respectively. However, the median cumulative risk weighted exposure based on combined probability was found to be greater for practices vs. games. These data will provide a metric that may be used to better understand the cumulative effects of repetitive head impacts, injury mechanisms, and head impact exposure of

  18. Occupational and environmental human lead exposure in Brazil

    SciTech Connect

    Paoliello, M.M.B. . E-mail: monibas@sercomtel.com.br; De Capitani, E.M.

    2007-02-15

    The purpose of this paper is to present a review of data on assessment of exposure and adverse effects due to environmental and occupational lead exposure in Brazil. Epidemiological investigations on children lead exposure around industrial and mining areas have shown that lead contamination is an actual source of concern. Lead in gasoline has been phasing out since the 1980s, and it is now completely discontinued. The last lead mining and lead refining plant was closed in 1995, leaving residual environmental lead contamination which has recently been investigated using a multidisciplinary approach. Moreover, there are hundreds of small battery recycling plants and secondary smelting facilities all over the country, which produce focal urban areas of lead contamination. Current regulatory limits for workplace lead exposure have shown to be inadequate as safety limits according to a few studies carried out lately.

  19. Effects of low level exposure to lead on neurophysiological functions among lead battery workers.

    PubMed

    Kovala, T; Matikainen, E; Mannelin, T; Erkkilä, J; Riihimäki, V; Hänninen, H; Aitio, A

    1997-07-01

    Assessment of neurophysiological functions in workers with low level exposure to lead and evaluation of the efficacy of bone lead measurements in the prediction of effects of lead. Exposure to lead of 60 workers from a lead battery battery factory was estimated from historical blood lead measurements and analysis of lead in the tibial and calcaneal bones with x ray fluorescence. Peripheral and central nervous system functions were assessed by measuring conduction velocities, sensory distal latencies, sensory amplitudes, and vibration thresholds as well as by quantitative measurement of the absolute and relative powers and mean frequencies of different electroencephalograph (EEG) channels. Sensory amplitudes, and to a smaller degree sensory or motor conduction velocities, showed a negative correlation with long term exposure to lead, most clearly with integrated blood lead concentration and exposure time. Vibration thresholds measured in the arm were related to recent exposure to lead, those measured in the leg to long term exposure. The alpha and beta activities of the EEG were more abundant in subjects with higher long term exposure to lead. Calcaneal lead content reflected short term exposure, tibial lead content reflected long term exposure. Blood lead history showed a closer relation with effects of lead than the tibial or calcaneal lead concentrations. Vibratory thresholds, quantitative EEG, and to a smaller extent the sensory amplitude, provide sensitive measures of effects of lead in occupationally exposed adults. Most accurate estimates of health risks induced by lead can be obtained from a good history of blood lead measurements. If such a history of blood lead concentrations is not available, analysis of bone lead may be used for the assessment of health risks.

  20. Cumulative occupational mechanical exposures during working life and risk of sickness absence and disability pension: prospective cohort study.

    PubMed

    Sundstrup, Emil; Hansen, Åse Marie; Mortensen, Erik Lykke; Poulsen, Otto Melchior; Clausen, Thomas; Rugulies, Reiner; Møller, Anne; Andersen, Lars L

    2017-09-01

    Objectives The aim of this study was to determine the prospective association of cumulative mechanical exposure during working life with health-related labor market outcomes. Methods This prospective cohort study combines data from 5076 older workers (age 49-63 years) from the Copenhagen Aging and Midlife Biobank with a job exposure matrix and a national register containing information on social transfer payment. By coding individual job histories from the Danish version of ISCO-codes (International Standard Classification of Occupations), we calculated cumulative occupational mechanical exposures from a JEM for ton-years (lifting 1000 kg each day in one year), lifting-years (lifting loads weighing ≥20 kg >10 times each day in one year), kneeling-years (kneeling for one hour each day in one year) and vibration-years (whole-body vibration for one hour each day in one year). Cox-regression analyses estimated the relative risk of register-based long-term sickness absence (LTSA) and disability pension with cumulative occupational mechanical exposures throughout working life. Analyses were censored for competing events and adjusted for multiple confounders. Results During the follow-up period, 970 persons (19.3%) had ≥1 episode of LTSA and 85 persons (1.7%) were granted a disability pension. Number of ton-, lifting- and kneeling-years showed an exposure-response association with increased risk of LTSA (P<0.0001). In addition, both long term [≥20 years; hazard ratio (HR) 1.76 95% CI 1.39-2.22] and short term (<10 years; HR 1.20 95% CI 1.02-1.41) exposure to kneeling work increased the risk of LTSA. Lifting-years, but not the other mechanical exposures, were associated with risk of disability pension (HR 1.75 95% CI 1.01-3.04). Conclusions Cumulative occupational mechanical exposures during working life - such as lifting and kneeling work - increased the risk of LTSA. Importantly, being exposed to lifting increased the risk of disability pension.

  1. Soil is an important pathway of human lead exposure.

    PubMed Central

    Mielke, H W; Reagan, P L

    1998-01-01

    This review shows the equal or greater importance of leaded gasoline-contaminated dust compared to lead-based paint to the child lead problem, and that soil lead, resulting from leaded gasoline and pulverized lead-based paint, is at least or more important than lead-based paint (intact and not pulverized) as a pathway of human lead exposure. Because lead-based paint is a high-dose source, the biologically relevant dosage is similar to lead in soil. Both lead-based paint and soil lead are associated with severe lead poisoning. Leaded gasoline and lead in food, but not lead-based paint, are strongly associated with population blood lead levels in both young children and adults. Soil lead and house dust, but not lead-based paint, are associated with population blood lead levels in children. Most soil lead and house dust are associated with leaded gasoline. Lead-based paint dust is associated with cases of renovation of either exterior or interior environments in which the paint was pulverized. Based upon the limited data to date, abatement of soil lead is more effective than abatement of lead-based paint in reducing blood lead levels of young children. About equal numbers of children under 7 years of age are exposed to soil lead and lead-based paint. Seasonality studies point to soil lead as the main source of population blood lead levels. Soil lead is a greater risk factor than lead-based paint to children engaged in hand-to-mouth and pica behavior. In summary, soil lead is important for addressing the population of children at risk of lead poisoning. When soil lead is acknowledged by regulators and the public health community as an important pathway of human lead exposure, then more effective opportunities for improving primary lead prevention can become a reality. Images Figure 1 PMID:9539015

  2. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study

    SciTech Connect

    Laurer, G.R.; Cohen, N. . Dept. of Environmental Medicine); Stark, A.; Ju, C. . Bureau of Environmental and Occupational Epidemiology)

    1991-05-01

    The objective of this study is to demonstrate the feasibility of estimating cumulative exposure of individuals to low concentrations of radon by measuring the amount of Pb-A-10 in their skeletons. This report presents progress to date establishing the validity of an vivo technique to measure skeletal burdens of Pb-210, accumulated from exposure to radon and radon progeny. With the skeletal content of Pb--210 and a model for Pb metabolism, cumulative exposure to radon and its short-lived daughters (radon/daughters) may be calculated for use in deriving a dose-response relationship between lung cancer and exposure to radon/daughters. Data are presented for 29 subjects exposed to above-average'' radon concentrations in their homes, showing the correlation between measured Pb--210 burdens, and measured pCi/l and WLM exposure estimates. Their results are compared to measurements of a population of 24 subject's presumed exposed to average concentrations. Measurements of a Pennsylvania family exposed for a year in a home with an extremely high radon content are also presented. Update of results of an ongoing study of the biological half-time of Pb--210 in man involving measurements, of a retired radiation worker with a 40 year old skeletal burden of Pb-210.

  3. Lead Exposure and Cardiovascular Disease—A Systematic Review

    PubMed Central

    Navas-Acien, Ana; Guallar, Eliseo; Silbergeld, Ellen K.; Rothenberg, Stephen J.

    2007-01-01

    Objective This systematic review evaluates the evidence on the association between lead exposure and cardiovascular end points in human populations. Methods We reviewed all observational studies from database searches and citations regarding lead and cardiovascular end points. Results A positive association of lead exposure with blood pressure has been identified in numerous studies in different settings, including prospective studies and in relatively homogeneous socioeconomic status groups. Several studies have identified a dose–response relationship. Although the magnitude of this association is modest, it may be underestimated by measurement error. The hypertensive effects of lead have been confirmed in experimental models. Beyond hypertension, studies in general populations have identified a positive association of lead exposure with clinical cardiovascular outcomes (cardiovascular, coronary heart disease, and stroke mortality; and peripheral arterial disease), but the number of studies is small. In some studies these associations were observed at blood lead levels < 5 μg/dL. Conclusions We conclude that the evidence is sufficient to infer a causal relationship of lead exposure with hypertension. We conclude that the evidence is suggestive but not sufficient to infer a causal relationship of lead exposure with clinical cardiovascular outcomes. There is also suggestive but insufficient evidence to infer a causal relationship of lead exposure with heart rate variability. Public Health Implications These findings have immediate public health implications. Current occupational safety standards for blood lead must be lowered and a criterion for screening elevated lead exposure needs to be established in adults. Risk assessment and economic analyses of lead exposure impact must include the cardiovascular effects of lead. Finally, regulatory and public health interventions must be developed and implemented to further prevent and reduce lead exposure. PMID:17431501

  4. Children’s Phthalate Intakes and Resultant Cumulative Exposures Estimated from Urine Compared with Estimates from Dust Ingestion, Inhalation and Dermal Absorption in Their Homes and Daycare Centers

    PubMed Central

    Bekö, Gabriel; Weschler, Charles J.; Langer, Sarka; Callesen, Michael; Toftum, Jørn; Clausen, Geo

    2013-01-01

    Total daily intakes of diethyl phthalate (DEP), di(n-butyl) phthalate (DnBP), di(isobutyl) phthalate (DiBP), butyl benzyl phthalate (BBzP) and di(2-ethylhexyl) phthalate (DEHP) were calculated from phthalate metabolite levels measured in the urine of 431 Danish children between 3 and 6 years of age. For each child the intake attributable to exposures in the indoor environment via dust ingestion, inhalation and dermal absorption were estimated from the phthalate levels in the dust collected from the child’s home and daycare center. Based on the urine samples, DEHP had the highest total daily intake (median: 4.42 µg/d/kg-bw) and BBzP the lowest (median: 0.49 µg/d/kg-bw). For DEP, DnBP and DiBP, exposures to air and dust in the indoor environment accounted for approximately 100%, 15% and 50% of the total intake, respectively, with dermal absorption from the gas-phase being the major exposure pathway. More than 90% of the total intake of BBzP and DEHP came from sources other than indoor air and dust. Daily intake of DnBP and DiBP from all exposure pathways, based on levels of metabolites in urine samples, exceeded the Tolerable Daily Intake (TDI) for 22 and 23 children, respectively. Indoor exposures resulted in an average daily DiBP intake that exceeded the TDI for 14 children. Using the concept of relative cumulative Tolerable Daily Intake (TDIcum), which is applicable for phthalates that have established TDIs based on the same health endpoint, we examined the cumulative total exposure to DnBP, DiBP and DEHP from all pathways; it exceeded the tolerable levels for 30% of the children. From the three indoor pathways alone, several children had a cumulative intake that exceeded TDIcum. Exposures to phthalates present in the air and dust indoors meaningfully contribute to a child’s total intake of certain phthalates. Such exposures, by themselves, may lead to intakes exceeding current limit values. PMID:23626820

  5. Cohort mortality study of workers at seven beryllium processing plants: update and associations with cumulative and maximum exposure.

    PubMed

    Schubauer-Berigan, Mary K; Couch, James R; Petersen, Martin R; Carreón, Tania; Jin, Yan; Deddens, James A

    2011-05-01

    To extend follow-up of cause-specific mortality in workers at seven beryllium processing plants and to estimate associations between mortality risk and beryllium exposure. 9199 workers were followed for mortality from 1940 through 2005. Standardised mortality ratios (SMRs) were estimated based on US population comparisons for lung, nervous system and urinary tract cancers, chronic obstructive pulmonary disease (COPD), chronic kidney disease, and categories containing chronic beryllium disease (CBD) and cor pulmonale. Associations with maximum and cumulative exposure were calculated for a subset of the workers. Overall mortality in the cohort compared with the US population was elevated for lung cancer (SMR 1.17; 95% CI 1.08 to 1.28), COPD (SMR 1.23; 95% CI 1.13 to 1.32), and the categories containing CBD (SMR 7.80; 95% CI 6.26 to 9.60) and cor pulmonale (SMR 1.17; 95% CI 1.08 to 1.26). Mortality rates for most diseases of interest increased with time-since-hire. For the category including CBD, rates were substantially elevated compared to the US population across all exposure groups. Workers whose maximum beryllium exposure was ≥ 10 μg/m(3) had higher rates of lung cancer, urinary tract cancer, COPD and the category containing cor pulmonale than workers with lower exposure. Significant positive trends with cumulative exposure were observed for nervous system cancers (p = 0.0006) and, when short-term workers were excluded, lung cancer (p = 0.01), urinary tract cancer (p = 0.003) and COPD (p < 0.0001). These findings reaffirm that lung cancer and CBD, and suggest that COPD and nervous system and urinary tract cancers, are related to beryllium exposure. Cigarette smoking and exposure to other lung carcinogens are unlikely to explain these elevations.

  6. Identification and Quantification of Cumulative Factors that Increase Environmental Exposures and Impacts

    EPA Science Inventory

    Evaluating the combined adverse effects of multiple stressors upon human health is an imperative component of cumulative risk assessment (CRA)1. In addition to chemical stressors, other non-chemical factors are also considered. For examples, smoking will elevate the risks of havi...

  7. TESTING STRATEGIES TO ESTIMATE NEUROTOXIC RISK FOR CUMULATIVE EXPOSURE TO PYRETHROID MIXTURES.

    EPA Science Inventory

    The Food Quality Protection Act requires EPA to consider the cumulative risk of pesticides with

    a common mechanism-of-toxicity. Evidence supports a mechanistic commonality for pyrethroid

    insecticides: these chemicals all act on neuronal sodium channels. The lack of ...

  8. Tools Available to Communities for Conducting Cumulative Exposure and Risk Assessments

    EPA Science Inventory

    This paper summarizes and assesses over 70 tools that could aid with gathering information and taking action on environmental issues related to community-based cumulative risk assessments (CBCRA). Information on tool use, development and research needs, was gathered from websites...

  9. Estimating Greenspace Exposure and Benefits for Cumulative Risk Assessment Applications (Summary Report)

    EPA Science Inventory

    This document provides a summary of the technical meeting on greenspace (GS) and cumulative risk assessment convened May 4−5, 2015 in Cincinnati, OH, by the U.S. Environmental Protection Agency (EPA) Office of Research and Development (ORD) National Center for Environmental As...

  10. Identification and Quantification of Cumulative Factors that Increase Environmental Exposures and Impacts

    EPA Science Inventory

    Evaluating the combined adverse effects of multiple stressors upon human health is an imperative component of cumulative risk assessment (CRA)1. In addition to chemical stressors, other non-chemical factors are also considered. For examples, smoking will elevate the risks of havi...

  11. TESTING STRATEGIES TO ESTIMATE NEUROTOXIC RISK FOR CUMULATIVE EXPOSURE TO PYRETHROID MIXTURES.

    EPA Science Inventory

    The Food Quality Protection Act requires EPA to consider the cumulative risk of pesticides with

    a common mechanism-of-toxicity. Evidence supports a mechanistic commonality for pyrethroid

    insecticides: these chemicals all act on neuronal sodium channels. The lack of ...

  12. Tools Available to Communities for Conducting Cumulative Exposure and Risk Assessments

    EPA Science Inventory

    This paper summarizes and assesses over 70 tools that could aid with gathering information and taking action on environmental issues related to community-based cumulative risk assessments (CBCRA). Information on tool use, development and research needs, was gathered from websites...

  13. Estimating Greenspace Exposure and Benefits for Cumulative Risk Assessment Applications (Summary Report)

    EPA Science Inventory

    This document provides a summary of the technical meeting on greenspace (GS) and cumulative risk assessment convened May 4−5, 2015 in Cincinnati, OH, by the U.S. Environmental Protection Agency (EPA) Office of Research and Development (ORD) National Center for Environmental As...

  14. Measuring Lead Exposure in Infants, Children, and Other Sensitive Populations.

    ERIC Educational Resources Information Center

    National Academy of Sciences - National Research Council, Washington, DC.

    Adverse health effects from exposure to lead are now recognized to be among industrialized society's most important health problems. This report, prepared by the National Research Council's Committee on Measuring Lead Exposure in Critical Populations, concurs with new findings issued by the Centers for Disease Control which state that lead…

  15. Lead exposures in the human environment. Final report

    SciTech Connect

    Elias, R.W.

    1985-01-01

    Humans consume lead by inhaling air, drinking beverages, eating food and ingesting dust. The natural source of this lead is primarily soil. Anthropogenic sources are lead in gasoline, fossil fuels and industrial products and processes. Lead is ubiquitous in the human environment, and pinpointing the primary sources of lead in any particular environmental component is difficult. Nevertheless, our purpose is to describe the total exposure of humans to environmental lead and to determine the sources of lead contributing to this exposure. The total exposure is the total amount of lead consumed by ingestion and inhalation. Excluding lead exposure from choice or circumstance, a baseline level of potential human exposure can be defined for a normal individual eating a typical diet and living in a non-urban community remote from industrial sources of lead in a house without lead-based paints. Beyond this level, additive exposure factors can be determined for other environments (e.g. urban, occupational and smelter communities) and for certain habits and activities (e.g. pica, smoking, drinking and hobbies), with variation for age, sex or socioeconomic status.

  16. Gα12 activation in podocytes leads to cumulative changes in glomerular collagen expression, proteinuria and glomerulosclerosis.

    PubMed

    Boucher, Ilene; Yu, Wanfeng; Beaudry, Sarah; Negoro, Hideyuki; Tran, Mei; Pollak, Martin R; Henderson, Joel M; Denker, Bradley M

    2012-05-01

    Glomerulosclerosis is a common pathological finding that often progresses to renal failure. The mechanisms of chronic kidney disease progression are not well defined, but may include activation of numerous vasoactive and inflammatory pathways. We hypothesized that podocytes are susceptible to filtered plasma components, including hormones and growth factors that stimulate signaling pathways leading to glomerulosclerosis. Gα12 couples to numerous G-protein-coupled receptors (GPCRs) and regulates multiple epithelial responses, including proliferation, apoptosis, permeability and the actin cytoskeleton. Herein, we report that genetic activation of Gα12 in podocytes leads to time-dependent increases in proteinuria and glomerulosclerosis. To mimic activation of Gα12 pathways, constitutively active Gα12 (QL) was conditionally expressed in podocytes using Nphs2-Cre and LacZ/floxed QLα12 transgenic mice. Some QLα12(LacZ+/Cre+) mice developed proteinuria at 4-6 months, and most were proteinuric by 12 months. Proteinuria increased with age, and by 12-14 months, many demonstrated glomerulosclerosis with ultrastructural changes, including foot process fusion and both mesangial and subendothelial deposits. QLα12(LacZ+/Cre+) mice showed no changes in podocyte number, apoptosis, proliferation or Rho/Src activation. Real-time PCR revealed no significant changes in Nphs1, Nphs2, Cd2ap or Trpc6 expression, but Col4a2 message was increased in younger and older mice, while Col4a5 was decreased in older mice. Confocal microscopy revealed disordered collagen IVα1/2 staining in older mice and loss of α5 without changes in other collagen IV subunits. Taken together, these studies suggest that Gα12 activation promotes glomerular injury without podocyte depletion through a novel mechanism regulating collagen (α)IV expression, and supports the notion that glomerular damage may accrue through persistent GPCR activation in podocytes.

  17. Trends in occupational lead exposure since the 1978 OSHA lead standard.

    PubMed

    Okun, Andrea; Cooper, Gregory; Bailer, A John; Bena, James; Stayner, Leslie

    2004-06-01

    The purpose of the study was to evaluate trends in occupational lead exposures throughout U.S. industry after the establishment of the general industry lead standard in 1978 and the construction industry standard in 1993. Lead exposure measurements collected by the Occupational Safety and Health Administration (OSHA) under their compliance and consultation programs were analyzed. Time trends in the distributions of exposure levels were evaluated graphically. Trends in the proportion of exposures above the OSHA permissible exposure limit (PEL) were analyzed using logistic regression models. The distribution of lead exposure levels declined over the study time period for general industry, but not for construction. The median exposure levels for general industry facilities decreased five- to tenfold. Logistic regression models reveal statistically significant declines in the odds of a lead exposure exceeding the PEL. This study provides evidence for relatively large decreases in lead exposure levels in general industry facilities over time. The study does not provide similar evidence for the construction industry. Given the limited number of years of data available since the implementation of the revised construction standard for lead, re-analysis of lead exposure levels within this industry would be worthwhile when more data become available.

  18. Lead exposure from battery recycling in Indonesia.

    PubMed

    Haryanto, Budi

    2016-03-01

    In Indonesia, more than 200 illegal used lead acid battery (ULAB) smelters are currently operating. Only a few health studies support the finding of lead-related symptoms and diseases among populations living near the smelters. To assess the blood lead levels (BLLs) and potential health impacts among the population surrounding ULAB recycling smelters, we evaluated health effects reported from 2003 to 2013, conducted focus group discussions with lead smelter owner/workers and a group of 35 female partners of smelter owners or workers not actively engaged in smelter work, and retook and measured BLLs. It was found that many children in the areas were having difficulty achieving high grades at school and having stunting or other problems with physical development. The average mean of BLLs increased by almost double in 2015, compared with in 2011. The risk of having hypertension, interference in the ability to make red blood cells in females occurred among 24% of respondents; Elevated blood pressure, hearing loss, and interference in the ability to make red bloods cell occurred in 20% of males; Kidney damage, infertility in male, nerve problems, including decreased sensation and decreased ability to move quickly occurred in 13%; Decreased ability to make red blood cells (20%), and; Frank anemia, decreased life-span, coma/seizures were experienced by 22%. The populations living in areas surrounding ULAB smelters are experiencing severe chronic health problems. It is recommended that the smelters must be moved and placed far away from the municipality.

  19. Effect Modification of the Association of Cumulative Exposure and Cancer Risk by Intensity of Exposure and Time Since Exposure Cessation: A Flexible Method Applied to Cigarette Smoking and Lung Cancer in the SYNERGY Study

    PubMed Central

    Vlaanderen, Jelle; Portengen, Lützen; Schüz, Joachim; Olsson, Ann; Pesch, Beate; Kendzia, Benjamin; Stücker, Isabelle; Guida, Florence; Brüske, Irene; Wichmann, Heinz-Erich; Consonni, Dario; Landi, Maria Teresa; Caporaso, Neil; Siemiatycki, Jack; Merletti, Franco; Mirabelli, Dario; Richiardi, Lorenzo; Gustavsson, Per; Plato, Nils; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Tardón, Adonina; Zaridze, David; Field, John K.; 't Mannetje, Andrea; Pearce, Neil; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Stanescu Dumitru, Rodica; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Boffetta, Paolo; Forastiere, Francesco; Bueno-de-Mesquita, Bas; Peters, Susan; Brüning, Thomas; Kromhout, Hans; Straif, Kurt; Vermeulen, Roel

    2014-01-01

    The indiscriminate use of the cumulative exposure metric (the product of intensity and duration of exposure) might bias reported associations between exposure to hazardous agents and cancer risk. To assess the independent effects of duration and intensity of exposure on cancer risk, we explored effect modification of the association of cumulative exposure and cancer risk by intensity of exposure. We applied a flexible excess odds ratio model that is linear in cumulative exposure but potentially nonlinear in intensity of exposure to 15 case-control studies of cigarette smoking and lung cancer (1985–2009). Our model accommodated modification of the excess odds ratio per pack-year of cigarette smoking by time since smoking cessation among former smokers. We observed negative effect modification of the association of pack-years of cigarette smoking and lung cancer by intensity of cigarette smoke for persons who smoked more than 20–30 cigarettes per day. Patterns of effect modification were similar across individual studies and across major lung cancer subtypes. We observed strong negative effect modification by time since smoking cessation. Application of our method in this example of cigarette smoking and lung cancer demonstrated that reducing a complex exposure history to a metric such as cumulative exposure is too restrictive. PMID:24355332

  20. Effect modification of the association of cumulative exposure and cancer risk by intensity of exposure and time since exposure cessation: a flexible method applied to cigarette smoking and lung cancer in the SYNERGY Study.

    PubMed

    Vlaanderen, Jelle; Portengen, Lützen; Schüz, Joachim; Olsson, Ann; Pesch, Beate; Kendzia, Benjamin; Stücker, Isabelle; Guida, Florence; Brüske, Irene; Wichmann, Heinz-Erich; Consonni, Dario; Landi, Maria Teresa; Caporaso, Neil; Siemiatycki, Jack; Merletti, Franco; Mirabelli, Dario; Richiardi, Lorenzo; Gustavsson, Per; Plato, Nils; Jöckel, Karl-Heinz; Ahrens, Wolfgang; Pohlabeln, Hermann; Tardón, Adonina; Zaridze, David; Field, John K; 't Mannetje, Andrea; Pearce, Neil; McLaughlin, John; Demers, Paul; Szeszenia-Dabrowska, Neonila; Lissowska, Jolanta; Rudnai, Peter; Fabianova, Eleonora; Stanescu Dumitru, Rodica; Bencko, Vladimir; Foretova, Lenka; Janout, Vladimir; Boffetta, Paolo; Forastiere, Francesco; Bueno-de-Mesquita, Bas; Peters, Susan; Brüning, Thomas; Kromhout, Hans; Straif, Kurt; Vermeulen, Roel

    2014-02-01

    The indiscriminate use of the cumulative exposure metric (the product of intensity and duration of exposure) might bias reported associations between exposure to hazardous agents and cancer risk. To assess the independent effects of duration and intensity of exposure on cancer risk, we explored effect modification of the association of cumulative exposure and cancer risk by intensity of exposure. We applied a flexible excess odds ratio model that is linear in cumulative exposure but potentially nonlinear in intensity of exposure to 15 case-control studies of cigarette smoking and lung cancer (1985-2009). Our model accommodated modification of the excess odds ratio per pack-year of cigarette smoking by time since smoking cessation among former smokers. We observed negative effect modification of the association of pack-years of cigarette smoking and lung cancer by intensity of cigarette smoke for persons who smoked more than 20-30 cigarettes per day. Patterns of effect modification were similar across individual studies and across major lung cancer subtypes. We observed strong negative effect modification by time since smoking cessation. Application of our method in this example of cigarette smoking and lung cancer demonstrated that reducing a complex exposure history to a metric such as cumulative exposure is too restrictive.

  1. Neurotoxicity and biomarkers of lead exposure: a review.

    PubMed

    Liu, Kang-sheng; Hao, Jia-hu; Zeng, Yu; Dai, Fan-chun; Gu, Ping-qing

    2013-09-01

    Appropriate selection and measurement of lead biomarkers of exposure are critically important for health care management purposes, public health decision making, and primary prevention synthesis. Lead is one of the neurotoxicants that seems to be involved in the etiology of psychologies. Biomarkers are generally classified into three groups: biomarkers of exposure, effect, and susceptibility.The main body compartments that store lead are the blood, soft tissues, and bone; the half-life of lead in these tissues is measured in weeks for blood, months for soft tissues, and years for bone. Within the brain, lead-induced damage in the prefrontal cerebral cortex, hippocampus, and cerebellum can lead to a variety of neurological disorders, such as brain damage, mental retardation, behavioral problems, nerve damage, and possibly Alzheimer's disease, Parkinsons disease, and schizophrenia. This paper presents an overview of biomarkers of lead exposure and discusses the neurotoxic effects of lead with regard to children and adults.

  2. Epigenome: Biosensor of Cumulative Exposure to Chemical and Nonchemical Stressors Related to Environmental Justice

    PubMed Central

    Gruber, David; Sonawane, Babasaheb

    2014-01-01

    Understanding differential disease susceptibility requires new tools to quantify the cumulative effects of environmental stress. Evidence suggests that social, physical, and chemical stressors can influence disease through the accumulation of epigenetic modifications. Geographically stable epigenetic alterations could identify plausible mechanisms for health disparities among the disadvantaged and poor. Relations between neighborhood-specific epigenetic markers and disease would identify the most appropriate targets for medical and environmental intervention. Complex interactions among genes, the environment, and disease require the examination of how epigenetic changes regulate susceptibility to environmental stressors. Progress in understanding disparities in disease susceptibility may depend on assessing the cumulative effect of environmental stressors on genetic substrates. We highlight key concepts regarding the interface between environmental stress, epigenetics, and chronic disease. PMID:25122010

  3. Epigenome: biosensor of cumulative exposure to chemical and nonchemical stressors related to environmental justice.

    PubMed

    Olden, Kenneth; Lin, Yu-Sheng; Gruber, David; Sonawane, Babasaheb

    2014-10-01

    Understanding differential disease susceptibility requires new tools to quantify the cumulative effects of environmental stress. Evidence suggests that social, physical, and chemical stressors can influence disease through the accumulation of epigenetic modifications. Geographically stable epigenetic alterations could identify plausible mechanisms for health disparities among the disadvantaged and poor. Relations between neighborhood-specific epigenetic markers and disease would identify the most appropriate targets for medical and environmental intervention. Complex interactions among genes, the environment, and disease require the examination of how epigenetic changes regulate susceptibility to environmental stressors. Progress in understanding disparities in disease susceptibility may depend on assessing the cumulative effect of environmental stressors on genetic substrates. We highlight key concepts regarding the interface between environmental stress, epigenetics, and chronic disease.

  4. Worker lead exposures during renovation of homes with lead-based paint

    SciTech Connect

    Sussell, A.; Gittleman, J.; Singal, M.

    1998-11-01

    The authors evaluated lead exposures among full-time home renovators and part-time volunteers working primarily in pre-1960 homes with lead-based paint. Potentially hazardous lead exposures were measured during two tasks: exterior dry scraping and wet scraping. Maximum exposures were 120 and 63 {micro}g/m{sup 3}, respectively. Exposures during other tasks, including general repair, weatherization, exterior scraping/painting, window replacement, demolition, and plumbing, were low, as were all 13 full-shift personal exposures. Blood lead levels for full-time workers ranged up to 17.5 {micro}g/dl, with a GM of 5.2 {micro}g/dl; the GM for volunteers was 3.2 {micro}g/dl. All of the paint samples collected from work surfaces had detectable amounts of lead, with 65% of the work surfaces tested having an average lead concentration of >0.5%.

  5. Cumulative exposure to high-strain and active jobs as predictors of cognitive function: the Whitehall II study

    PubMed Central

    Elovainio, Marko; Ferrie, Jane E.; Singh-Manoux, Archana; Gimeno, David; De Vogli, Roberto; Shipley, Martin J.; Vahtera, Jussi; Brunner, Eric J.; Marmot, Michael G.; Kivimaki, Mika

    2009-01-01

    Objectives A high strain job (a combination of high job demands and low job control) is expected to increase the risk of health problems, whereas an active job (high demands and high control) can be hypothesized to be associated with a greater capacity to learn. We tested associations between high strain and active jobs and cognitive function in middle-aged men and women. Methods Data on 4146 British civil servants (2,989 men and 1,157 women) aged 35–55 years at baseline came from the Whitehall II study. Cumulative exposure to both high strain and active jobs was assessed at Phases 1 (1985–1988), 2 (1989–1990) and 3 (1991–1993). Cognitive performance was assessed at Phases 5 (1997–1999) and 7 (2003–2004) using the following tests: verbal memory, inductive reasoning (Alice Heim), verbal meaning (Mill Hill), phonemic and semantic fluency. Analyses were adjusted for age, sex, and employment grade. Results Longer exposure to high job strain and shorter exposure to active jobs were associated with lower scores in most of the cognitive performance tests. However, these associations disappeared on adjustment for employment grade. Phonemic fluency was an exception to this pattern. Associations between exposure to an active job and phonemic fluency at both follow-up phases were robust to adjustment for employment grade. However, there was no association between exposure to active jobs and change in phonemic fluency score between the follow-up phases after adjustment for employment grade. Conclusions In these data associations between cumulative exposure to high strain or active jobs and cognition are largely explained by socioeconomic position. PMID:18805883

  6. Lead exposure increases blood pressure by increasing angiotensinogen expression.

    PubMed

    Jiao, Jiandong; Wang, Miaomiao; Wang, Yiqing; Sun, Na; Li, Chunping

    2016-01-01

    Lead exposure can induce increased blood pressure. Several mechanisms have been proposed to explain lead-induced hypertension. Changes in angiotensinogen (AGT) expression levels or gene variants may also influence blood pressure. In this study, we hypothesized that AGT expression levels or gene variants contribute to lead-induced hypertension. A preliminary HEK293 cell model experiment was performed to analyze the association between AGT expression and lead exposure. In a population-based study, serum AGT level was measured in both lead-exposed and control populations. To further detect the influence of AGT gene single nucleotide polymorphisms (SNPs) in lead-induced hypertension, two SNPs (rs699 and rs4762) were genotyped in a case-control study including 219 lead-exposed subjects and 393 controls. Lead exposure caused an increase in AGT expression level in HEK 293 cell models (P < 0.001) compared to lead-free cells, and individuals exposed to lead had higher systolic and diastolic blood pressure (P < 0.001). Lead-exposed individuals had higher serum AGT levels compared to controls (P < 0.001). However, no association was found between AGT gene SNPs (rs699 and rs4762) and lead exposure. Nevertheless, the change in AGT expression level may play an important role in the development of lead-induced hypertension.

  7. The management of lead exposure in pediatric populations

    SciTech Connect

    Barker, P.O.; Lewis, D.A. )

    1990-12-01

    Chronically elevated lead levels are a common problem affecting children. Although this problem occurs most frequently in the inner city, no community is safe from excessive pediatric lead exposure. Screening by erythrocyte protoporphyrin is a sensitive early indicator of rising lead levels. A Centers for Disease Control report recommends that all children be screened starting at 9 to 12 months. A classification system of various lead levels helps determine proper treatment. Health care practitioners need to be well-informed about lead exposure and how it occurs in order to educate parents. 10 refs.

  8. Dietary exposure to lead of adults in Shenzhen city, China.

    PubMed

    Pan, Liubo; Wang, Zhou; Peng, Zhaoqiong; Liu, Guihua; Zhang, Huimin; Zhang, Jinzhou; Jiang, Jie; Pathiraja, Nimal; Xiao, Ying; Jiao, Rui; Huang, Wei

    2016-07-01

    Lead, a ubiquitous heavy metal, can be found in the environment and food. The present study is the first to estimate the lead dietary exposure of Shenzhen adults (≥ 20 years old) in various age-gender subgroups, and to assess the associated health risk. Food samples that represented the Shenzhen people's dietary pattern were collected and prepared for analysis. Lead was determined in 13 food groups using 276 individual cooked samples by inductively coupled plasma-mass spectrometry (ICP-MS). Dietary exposures were estimated by combining the analytical results with the local food consumption data of Shenzhen adults. The mean and 95th percentile lead exposure of Shenzhen adults were 0.59-0.73 and 0.75-0.94 μg kg(-1) bw day(-1), respectively. In all food groups, the highest lead exposure was from 'Eggs and their products' (42.4-51.6% of the total exposure); preserved eggs being the main contributor. The other major contributors to lead exposure of Shenzhen adults were 'Fish and seafood, and their products' (14.3-16.7% of the total exposure) and 'Vegetables and their products' (15.5-16.2% of the total exposure). The margin of exposure (MOE) approach was used for the risk assessment of lead, and the results showed that the risk was considered to be low in all age-gender groups for Shenzhen adults. However, having considered a number of toxic effects of lead, it is suggested that more efforts should be made to reduce the lead levels in foodstuff for Shenzhen adults.

  9. Effect of cumulative ozone exposure on ozone-induced nasal epithelial hyperplasia and secretory metaplasia in rats

    SciTech Connect

    Hotchkiss, J.A.; Harkema, J.R.; Henderson, R.F. )

    1991-05-01

    Repeated exposure of rats to O3 induces proliferative and secretory metaplastic changes within nasal airway epithelia that may protect against subsequent exposures. Our study assessed the effect of different cumulative exposure times on O3-induced nasal epithelial hyperplasia and secretory metaplasia. Rats were exposed 6 h/day to air or to 0.8 ppm O3 and were sacrificed 18 h after the end of their last exposure. The rats were exposed to either air or 0.8 ppm O3 for 3 or 7 days, or to 0.8 ppm O3 for 3 days followed by a 4-day exposure to air. The effects of the exposures were determined by quantitating the hyperplastic (epithelial nuclei/mm basal lamina) and secretory metaplastic changes (volume densities of acidic and neutral mucosubstances) within the nasal nonciliated cuboidal epithelium (NNCE). There were no significant changes in NNCE cell numeric density, or in the volume density of intraepithelial mucus, compared to air-exposed control rats, in rats exposed to O3 for 3 days and sacrificed 18 h later. Compared to control rats, there was significant epithelial hyperplasia and secretory metaplasia within the NNCE of rats exposed to O3 either for 7 days or for 3 days followed by 4 days of exposure to air. There were no significant differences in NNCE cell hyperplasia or secretory metaplasia between these two experimental groups. Three 6 h/day exposures to 0.8 ppm O3 triggered hyperplastic and metaplastic changes within rat NNCE that were indistinguishable from those produced by seven 6 h/day exposures to the same concentration of O3. The data suggest that O3 is capable of rapidly inducing hyperplastic and metaplastic responses within rat NNCE, and that once initiated, development of the phenotypic changes within the epithelium does not require further O3 exposure.

  10. Current and historical individual data about exposure of workers in the rayon industry to carbon disulfide and their validity in calculating the cumulative dose.

    PubMed

    Göen, Thomas; Schramm, Axel; Baumeister, Thomas; Uter, Wolfgang; Drexler, Hans

    2014-08-01

    The objective of the study was to investigate how exposure to carbon disulfide (CS2) in a rayon-manufacturing plant has changed within two decades and whether it is possible to calculate valid data for the individual cumulative exposure. The data for CS2 concentration in air and biological exposure monitoring (2-thio-1,3-thiaxolidine-4-carboxylic acid (TTCA) in urine) from two cross-sectional studies, performed in 1992 (n = 362) and 2009 (n = 212) in a German rayon-manufacturing plant, were compared to data obtained from company-internal measurements between the studies. Using the data from the cross-sectional studies and company-internal data, cumulative external exposure and the cumulative internal exposure were calculated for each worker. External and internal CS2 exposure of the employees decreased from 1992 (medians 4.0 ppm and 1.63 mgTTCA/g creatinine) to 2009 (medians 2.5 ppm and 0.86 mg/g). However, company-internal CS2 data do not show a straight trend for this period. The annual medians of the company-internal measurement of external exposure to CS2 have varied between 2.7 and 8.4 ppm, in which median values exceeded 5 ppm generally since 2000. The annual medians for the company-internal biomonitoring assessment ranged between 1.2 and 2.8 mg/g creatinine. The cumulative CS2 exposure ranged from 8.5 to 869.5 ppm years for external exposure and between 1.30 and 176.2 mg/g creatinine years for the internal exposure. Significant correlations were found between the current air pollution and the internal exposure in 2009 but also between the cumulative external and internal CS2 exposure. Current exposure data, usually collected in cross-sectional studies, rarely allow a reliable statement on the cumulative dose, because of higher exposure in the past and of fluctuating courses of exposure. On the other hand, company-internal exposure data may be affected by non-representative measurement strategies. Some verification of the reliability of

  11. DIETARY EXPOSURE OF CHILDREN IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors; they have more opportunity for contact with lead sources due to their activities, lead absorption occurs more readily in a child compared to an adult, and the child's development i...

  12. DIETARY EXPOSURE OF CHILDREN LIVING IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors: they have more opportunity for contact with lead sources due to their activities; lead absorption occurs more readily in a child as compared to an adult; and the child's developmen...

  13. DIETARY EXPOSURE OF CHILDREN IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors; they have more opportunity for contact with lead sources due to their activities, lead absorption occurs more readily in a child compared to an adult, and the child's development i...

  14. DIETARY EXPOSURE OF CHILDREN LIVING IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors: they have more opportunity for contact with lead sources due to their activities; lead absorption occurs more readily in a child as compared to an adult; and the child's developmen...

  15. Biological monitoring of child lead exposure in the Czech Republic.

    PubMed Central

    Cikrt, M; Smerhovsky, Z; Blaha, K; Nerudova, J; Sediva, V; Fornuskova, H; Knotkova, J; Roth, Z; Kodl, M; Fitzgerald, E

    1997-01-01

    The area around the Pribram lead smelter has been recognized to be heavily contaminated by lead (Pb). In the early 1970s, several episodes of livestock lead intoxication were reported in this area; thereafter, several epidemiological and ecological studies focused on exposure of children. In contrast to earlier studies, the recent investigation (1992-1994) revealed significantly lower exposure to lead. From 1986-1990, recorded average blood lead levels were about 37.2 micrograms lead (Pb)/100 ml in an elementary school population living in a neighborhood close to the smelter (within 3 km of the plant). The present study, however, has found mean blood lead levels of 11.35 micrograms/100 ml (95% CI = 9.32; 13.82) among a comparable group of children. In addition to blood lead, tooth lead was used to assess exposure among children. Statistically significant differences (p < 0.05) were observed between the geometric mean tooth lead level of 6.44 micrograms Pb/g (n = 13; 95% CI = 3.95; 10.50) in the most contaminated zone and 1.43 micrograms Pb/g (n = 35; 95% CI = 1.11; 1.84) in zones farther away from the point source. Both biomarkers, blood and tooth lead levels, reflect a similar pattern of lead exposure in children. This study has attempted a quantitative assessment of risk factors associated with elevated lead exposure in the Czech Republic. Content of lead in soil, residential distance from the smelter, consumption of locally grown vegetables or fruits, drinking water from local wells, the mother's educational level, cigarette consumption among family members, and the number of children in the family were factors positively related (p < 0.05) to blood lead levels. The resulting blood lead level was found to be inversely proportional to the child's age. Images Figure 1. PMID:9189705

  16. Chronic lead exposure reduces junctional resistance at an electrical synapse.

    PubMed

    Audesirk, G; Audesirk, T

    1984-01-01

    Both acute and chronic lead exposure have been found to inhibit transmission at chemical synapses, possibly by interfering with inward calcium current. We have found that chronic lead exposure slightly reduces input resistance and greatly reduces the junctional resistance between two strongly electrically coupled neurons in the pond snail Lymnaea stagnalis. The net effect is to increase the strength of electrical coupling. A reduction in gap junctional resistance would also be expected to increase the flow of small molecules between cells. However, Lucifer Yellow injections did not reveal dye-coupling between the cells. Lead exposure also increases the capacitance of the neurons.

  17. Effect of exposure to lead on reproduction in male rats

    SciTech Connect

    Piasek, M.; Kostial, K.

    1987-09-01

    The objective of present study was to determine the effect of chronic oral exposure to different levels of lead on male reproductive performance since oral exposure data are more relevant to human environmental exposure. Additionally, most previous results have been obtained after parenteral administration of lead. These experiments were performed on rats by using the incidence of pregnancy to assess male fertility and litter size and pup weight as indicators of the lead effect on perinatal development. Similar parameters were used in reproduction studies by other authors.

  18. Prenatal Lead Exposure and Weight of 0- to 5-Year-Old Children in Mexico City

    PubMed Central

    Peterson, Karen E.; Sánchez, Brisa N.; Cantonwine, David; Lamadrid-Figueroa, Héctor; Schnaas, Lourdes; Ettinger, Adrienne S.; Hernández-Avila, Mauricio; Hu, Howard; Téllez-Rojo, Martha M.

    2011-01-01

    Background: Cumulative prenatal lead exposure, as measured by maternal bone lead burden, has been associated with smaller weight of offspring at birth and 1 month of age, but no study has examined whether this effect persists into early childhood. Objective: We investigated the association of perinatal maternal bone lead, a biomarker of cumulative prenatal lead exposure, with children’s attained weight over time from birth to 5 years of age. Methods: Children were weighed at birth and at several intervals up until 60 months. Maternal tibia and patella lead were measured at 1 month postpartum using in vivo K-shell X-ray fluorescence. We used varying coefficient models with random effects to assess the association of maternal bone lead with weight trajectories of 522 boys and 477 girls born between 1994 and 2005 in Mexico City. Results: After controlling for breast-feeding duration, maternal anthropometry, and sociodemographic characteristics, a 1-SD increase in maternal patella lead (micrograms per gram) was associated with a 130.9-g decrease in weight [95% confidence interval (CI), –227.4 to –34.4 g] among females and a 13.0-g nonsignificant increase in weight among males (95% CI, –73.7 to 99.9 g) at 5 years of age. These associations were similar after controlling for concurrent blood lead levels between birth and 5 years. Conclusions: Maternal bone lead was associated with lower weight over time among female but not male children up to 5 years of age. Given that the association was evident for patellar but not tibial lead levels, and was limited to females, results need to be confirmed in other studies. PMID:21715242

  19. Epigenetics, obesity and early-life cadmium or lead exposure.

    PubMed

    Park, Sarah S; Skaar, David A; Jirtle, Randy L; Hoyo, Cathrine

    2017-01-01

    Obesity is a complex and multifactorial disease, which likely comprises multiple subtypes. Emerging data have linked chemical exposures to obesity. As organismal response to environmental exposures includes altered gene expression, identifying the regulatory epigenetic changes involved would be key to understanding the path from exposure to phenotype and provide new tools for exposure detection and risk assessment. In this report, we summarize published data linking early-life exposure to the heavy metals, cadmium and lead, to obesity. We also discuss potential mechanisms, as well as the need for complete coverage in epigenetic screening to fully identify alterations. The keys to understanding how metal exposure contributes to obesity are improved assessment of exposure and comprehensive establishment of epigenetic profiles that may serve as markers for exposures.

  20. Environmental exposure to lead (Pb) and variations in its susceptibility.

    PubMed

    Kim, Jina; Lee, Youngeun; Yang, Mihi

    2014-01-01

    Based on exposure frequency and intrinsic toxicity, lead (Pb) ranks one of the highest priority toxic materials. Continuous regulation of environmental Pb exposure has contributed to dramatically diminished exposure levels of Pb, for example, blood level of Pb. However, the safety level of Pb is not established, as low-level exposure to Pb still shows severe toxicity in high susceptible population and late onset of some diseases from early exposure. In the present study, we focused on food-borne Pb exposure and found broad variations in Pb exposure levels via food among countries. In addition, there are genetic or ethnical variations in Pb-targeted and protective genes. Moreover, various epigenetic alterations were induced by Pb poisoning. Therefore, we suggest a systemic approach including governmental (public) and individual prevention from Pb exposure with continuous biological monitoring and genetic or epigenetic consideration.

  1. Acute and cumulative effects of different times of recovery from whole body vibration exposure on muscle performance.

    PubMed

    Da Silva-Grigoletto, Marzo E; Vaamonde, Diana M; Castillo, Eduardo; Poblador, Maria S; García-Manso, Juan M; Lancho, Jose L

    2009-10-01

    This experiment was designed to assess the acute (Study I) and cumulative response (Study II) of muscle performance to differing recovery times after exposure to whole body vibration (WBV). All subjects (mean age 19.7 +/- 1.9) were healthy and physically active. In both studies, subjects were exposed to a WBV bout of 6 exposures of 60 seconds each, with frequency of 30 Hz and amplitude of 4 mm. In Study I, subjects (n = 30) underwent 3 trials (1 per day) on different days with a 2-day wash-out period between trials; each trial included either a 1, 2, or 3 minutes of recovery between exposures to WBV. All subjects underwent all trials, which were randomly assigned. Jump ability and muscle power were measured before and after each bout. In Study II, subjects (n = 45) underwent 12 sessions of WBV training in 4 weeks (3 bouts/wk). The subjects were randomly assigned to 1 of the following 3 groups: WBV with 1-minute recovery periods between exposures, WBV with 2-minute recovery periods between exposures, or control group. Jump ability, muscle power, and strength were measured before and after each bout. In the acute study (I), recovery times of 1 and 2 minutes enhanced all measured parameters (p < 0.05), with the 2-minute recovery being more effective. In the long-term study (II), however, although both periods also enhanced the measured parameters (p < 0.05), the 1-minute recovery proved more effective because the response was modified by systematic stimulation. In conclusion, 2-minute recovery periods provided the most effective acute enhancement of muscle activation, whereas the 1-minute recovery provided a more effective cumulative enhancement of muscle power and jump ability.

  2. Childhood Lead Exposure from Battery Recycling in Vietnam.

    PubMed

    Daniell, William E; Van Tung, Lo; Wallace, Ryan M; Havens, Deborah J; Karr, Catherine J; Bich Diep, Nguyen; Croteau, Gerry A; Beaudet, Nancy J; Duy Bao, Nguyen

    2015-01-01

    Battery recycling facilities in developing countries can cause community lead exposure. To evaluate child lead exposure in a Vietnam battery recycling craft village after efforts to shift home-based recycling outside the village. This cross-sectional study evaluated 109 children in Dong Mai village, using blood lead level (BLL) measurement, parent interview, and household observation. Blood samples were analyzed with a LeadCare II field instrument; highest BLLs (≥45 μg/dL) were retested by laboratory analysis. Surface and soil lead were measured at 11 households and a school with X-ray fluorescence analyzer. All children had high BLLs; 28% had BLL ≥45 μg/dL. Younger age, family recycling, and outside brick surfaces were associated with higher BLL. Surface and soil lead levels were high at all tested homes, even with no recycling history. Laboratory BLLs were lower than LeadCare BLLs, in 24 retested children. In spite of improvements, lead exposure was still substantial and probably associated with continued home-based recycling, legacy contamination, and workplace take-home exposure pathways. There is a need for effective strategies to manage lead exposure from battery recycling in craft villages. These reported BLL values should be interpreted cautiously, although the observed field-laboratory discordance may reflect bias in laboratory results.

  3. Childhood Lead Exposure from Battery Recycling in Vietnam

    PubMed Central

    Van Tung, Lo; Wallace, Ryan M.; Havens, Deborah J.; Karr, Catherine J.; Bich Diep, Nguyen; Croteau, Gerry A.; Beaudet, Nancy J.; Duy Bao, Nguyen

    2015-01-01

    Background. Battery recycling facilities in developing countries can cause community lead exposure. Objective. To evaluate child lead exposure in a Vietnam battery recycling craft village after efforts to shift home-based recycling outside the village. Methods. This cross-sectional study evaluated 109 children in Dong Mai village, using blood lead level (BLL) measurement, parent interview, and household observation. Blood samples were analyzed with a LeadCare II field instrument; highest BLLs (≥45 μg/dL) were retested by laboratory analysis. Surface and soil lead were measured at 11 households and a school with X-ray fluorescence analyzer. Results. All children had high BLLs; 28% had BLL ≥45 μg/dL. Younger age, family recycling, and outside brick surfaces were associated with higher BLL. Surface and soil lead levels were high at all tested homes, even with no recycling history. Laboratory BLLs were lower than LeadCare BLLs, in 24 retested children. Discussion. In spite of improvements, lead exposure was still substantial and probably associated with continued home-based recycling, legacy contamination, and workplace take-home exposure pathways. There is a need for effective strategies to manage lead exposure from battery recycling in craft villages. These reported BLL values should be interpreted cautiously, although the observed field-laboratory discordance may reflect bias in laboratory results. PMID:26587532

  4. Immunological effects of occupational exposure to lead (Review).

    PubMed

    Fenga, Concettina; Gangemi, Silvia; Di Salvatore, Valentina; Falzone, Luca; Libra, Massimo

    2017-05-01

    It is well-known that occupational and environmental exposure to several factors, including benzene, heavy metals, chemicals and mineral fibers, is associated with the risk of developing a great number of diseases. Numerous studies have been carried out in order to investigate the mechanisms of toxicity of these substances, with particular regard to the possible toxic effects on the immune system. However, little is known about the influence of heavy metals, such as lead, on the immune system in human populations. Lead is a heavy metal still used in many industrial activities. Human exposure to lead can induce various biological effects depending upon the level and duration of exposure, such as toxic effects on haematological, cardiovascular, nervous and reproductive systems. Several studies demonstrated that exposure to lead is associated to toxic effects also on the immune system, thus increasing the incidence of allergy, infectious disease, autoimmunity or cancer. However, the effects of lead exposure on the human immune system are not conclusive, mostly in occupationally exposed subjects; nevertheless some immunotoxic abnormalities induced by lead have been suggested. In particular, in vivo, in vitro and ex vivo lead is able to improve T helper 2 (Th2) cell development affecting Th1 cell proliferation. Further studies are required to better understand the mechanisms of lead immunotoxicity and the ability of lead to affect preferentially one type of immune response.

  5. The Yugoslavia Prospective Study of environmental lead exposure.

    PubMed Central

    Factor-Litvak, P; Wasserman, G; Kline, J K; Graziano, J

    1999-01-01

    The Yugoslavia Prospective Study of environmental lead exposure has studied the associations between exposure to lead and pregnancy outcomes; childhood neuropsychological, behavioral, and physical development; and hematologic, renal, and cardiovascular function. The cohort comprises 577 children born to women recruited at midpregnancy in two towns in Kosovo, Yugoslavia; one town is the site of a lead smelter, refinery, and battery plant and the other is 25 miles away and relatively unexposed. A sample of these children has been followed at 6-month intervals through 7.5 years of age. Blood lead concentrations ranged from 1 to 70 microg/dl. Exposure to lead was not associated with adverse pregnancy outcomes. Exposure was associated with modest decrements in intelligence, small increases in blood pressure, higher risks of proteinuria, small increases in behavior problems, and perturbed hematopoiesis. Only at low level exposures (i.e., <16 microg/dl) were small associations with decreased height found. We discuss methodological problems that may hinder causal interpretation of these data, namely, use of blood lead concentration as an exposure measure, confounding, and town-specific associations. We conclude that while reported associations are small, collectively they lend support to the notion that lead is a toxicant with numerous adverse health effects. Images Figure 1 PMID:9872712

  6. EPA's SHEDS-multimedia model: children's cumulative pyrethroid exposure estimates and evaluation against NHANES biomarker data

    EPA Science Inventory

    The U.S. EPA's SHEDS-Multimedia model was applied to enhance the understanding of children's exposures and doses to multiple pyrethroid pesticides, including major contributing chemicals and pathways. This paper presents combined dietary and residential exposure estimates and cum...

  7. EPA's SHEDS-multimedia model: children's cumulative pyrethroid exposure estimates and evaluation against NHANES biomarker data

    EPA Science Inventory

    The U.S. EPA's SHEDS-Multimedia model was applied to enhance the understanding of children's exposures and doses to multiple pyrethroid pesticides, including major contributing chemicals and pathways. This paper presents combined dietary and residential exposure estimates and cum...

  8. Cumulative exposure to paternal seminal fluid prior to conception and subsequent risk of preeclampsia.

    PubMed

    Saftlas, Audrey F; Rubenstein, Linda; Prater, Kaitlin; Harland, Karisa K; Field, Elizabeth; Triche, Elizabeth W

    2014-03-01

    A growing body of literature suggests that prior and prolonged exposure to paternal antigens in seminal fluid induces maternal tolerance to the allogeneic fetus, protecting it from rejection and facilitating successful implantation and placentation. In this case-control study of nulliparous women, we test the hypothesis that increased exposure to paternal seminal fluid via the vaginal or oral route will confer a reduced risk of preeclampsia. Preeclampsia cases (n=258) and normotensive controls (n=182) were selected from live births to Iowa women over the period August 2002 to April 2005. Disease status was verified by medical chart review. Seminal fluid exposure indexes incorporated information on type and frequency of sexual practices, contraceptive use, and ingestion practices prior to conception with the baby's father. Preeclampsia risk decreased significantly with increasing vaginal exposure to paternal semen (test for trend p<0.05). Women in the highest 10th percentile of vaginal exposure had a 70% reduced odds of preeclampsia relative to women in the lowest 25th percentile of exposure (aOR=0.3; 95% CI: 0.1-0.9). Oral seminal fluid exposure was not associated with a reduced risk of preeclampsia. These findings are congruent with the immune maladaptation hypothesis of preeclampsia causation and indicate that paternal antigen exposure via the vaginal mucosa may facilitate immune tolerance to paternal HLA. Thus, advising nulliparous women to decrease their use of barrier contraceptive methods and to increase vaginal sexual intercourse prior to conceiving may reduce their risk of preeclampsia.

  9. The identification of lead ammunition as a source of lead exposure in First Nations: the use of lead isotope ratios.

    PubMed

    Tsuji, Leonard J S; Wainman, Bruce C; Martin, Ian D; Sutherland, Celine; Weber, Jean-Philippe; Dumas, Pierre; Nieboer, Evert

    2008-04-15

    The use of lead shotshell to hunt water birds has been associated with lead-contamination in game meat. However, evidence illustrating that lead shotshell is a source of lead exposure in subsistence hunting groups cannot be deemed definitive. This study seeks to determine whether lead shotshell constitutes a source of lead exposure using lead isotope ratios. We examined stable lead isotope ratios for lichens, lead shotshell and bullets, and blood from residents of Fort Albany and Kashechewan First Nations, and the City of Hamilton, Ontario, Canada. Data were analyzed using ANOVA and regression analyses. ANOVA of isotope ratios for blood revealed significant differences with respect to location, but not sex. Hamilton differed from both Kashechewan and Fort Albany; however, the First Nations did not differ from each other. ANOVA of the isotope ratios for lead ammunition and lichens revealed no significant differences between lichen groups (north and south) and for the lead ammunition sources (pellets and bullets). A plot of (206)Pb/(204)Pb and (206)Pb/(207)Pb values illustrated that lichens and lead ammunition were distinct groupings and only the 95% confidence ellipse of the First Nations group overlapped that of lead ammunition. In addition, partial correlations between blood-lead levels (adjusted for age) and isotope ratios revealed significant (p<0.05) positive correlations for (206)Pb/(204)Pb and (206)Pb/(207)Pb, and a significant negative correlation for (208)Pb/(206)Pb, as predicted if leaded ammunition were the source of lead exposure. In conclusion, lead ammunition was identified as a source of lead exposure for First Nations people; however, the isotope ratios for lead shotshell pellets and bullets were indistinguishable. Thus, lead-contaminated meat from game harvested with lead bullets may also be contributing to the lead body burden.

  10. Mortality and lead exposure: a retrospective cohort study of Swedish smelter workers.

    PubMed Central

    Gerhardsson, L; Lundström, N G; Nordberg, G; Wall, S

    1986-01-01

    The study is based on the work histories and mortality data for 3832 male workers first employed before 1967 at a copper smelter in northern Sweden and followed up from 1950 to 1981. From the 3832 workers a lead cohort consisting of 437 workers employed for at least three years at sites with considerable lead exposure during 1950-74 was selected. These workers had regularly had blood lead measurements performed since 1950. Based on the cumulative blood lead dose 1950-74 and peak blood lead values, the cohort was subdivided into high mean, low mean, high peak, and low peak groups. Standardised mortality ratios (SMR) were calculated for the six groups using general and local reference populations. The original cohort of 3832 workers showed considerable excess of deaths for total mortality, malignant neoplasms especially lung and stomach cancer, ischaemic heart diseases, and cerebrovascular diseases when compared with the general population. In the lead cohort where the workers had been subjected to a considerable lead exposure only the raised SMR for lung cancer was sustained (SMR = 162; not significant). No significant differences were found between high lead and low lead exposed smelter workers. PMID:3778840

  11. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study

    SciTech Connect

    Laurer, G.R.; Cohen, N. . Inst. of Environmental Medicine); Stark, A.; Ju, C. . Bureau of Environmental and Occupational Epidemiology)

    1990-10-01

    The feasibility of measuring Pb-210 in vivo in the skulls of those individuals who have resided in homes with above average levels of radon/radon daughters, has now been successfully demonstrated. These values, when incorporated into metabolic models of Pb-210 in the body including other related physical parameters, can be used for the calculation of a realistic estimate of a resident's cumulative exposure to radon and its' decay products. Data are presented for 26 subjects exposed to higher than average concentrations of radon i.e. ranging from 10 to 120 pCi/l, for various periods of time. Their skeletal Pb-210 burdens are compared to measurement results of a population of individuals presumed to have been exposed to values which are more representative of average levels i.e. <1pCi/1. Results of a study to determine the biological retention of Pb-210 in the human skeleton for use in the metabolic model relating skull burdens of this nuclide to cumulative radon/daughter exposure, are also described. At the present time, our measurements, made over a period of 10 years, of an individual with a significant Pb-210 burden, indicate a biological half-time of approximately 57 years and an effective half-life of 16 years. 4 refs., 11 figs.

  12. Control of excessive lead exposure in radiator repair workers

    SciTech Connect

    Not Available

    1991-03-01

    In 1988, 83 automotive repair workers with blood lead levels (BLLs) greater than 25 micrograms/dL were reported to state health departments in the seven states that collaborated with CDC's National Institute for Occupational Safety and Health (NIOSH) in maintaining registries of elevated BLLs in adults. In 18 (22%) of these 83 persons, BLLs were greater than 50 micrograms/dL. Among automotive repair workers for whom a job category was specified, radiator repair work was the principal source of lead exposure. The major sources of exposure for radiator repair workers are lead fumes generated during soldering and lead dust produced during radiator cleaning. This report summarizes current BLL surveillance data for radiator repair workers and describes three control technologies that are effective in reducing lead exposures in radiator repair shops.

  13. Control of excessive lead exposure in radiator repair workers.

    PubMed

    1991-03-01

    In 1988, 83 automotive repair workers with blood lead levels (BLLs) greater than 25 micrograms/dL were reported to state health departments in the seven states that collaborated with CDC's National Institute for Occupational Safety and Health (NIOSH) in maintaining registries of elevated BLLs in adults. In 18 (22%) of these 83 persons, BLLs were greater than 50 micrograms/dL. Among automotive repair workers for whom a job category was specified, radiator repair work was the principal source of lead exposure. The major sources of exposure for radiator repair workers are lead fumes generated during soldering and lead dust produced during radiator cleaning. This report summarizes current BLL surveillance data for radiator repair workers and describes three control technologies that are effective in reducing lead exposures in radiator repair shops.

  14. Exposure to lead in stained glass work. An environmental evaluation.

    PubMed

    Pant, B C; Harrison, J R; Long, G W; Gupta, S

    1994-01-25

    An environmental evaluation was conducted to determine lead exposure in a group of crafts people who produce stained glass and Tiffany glass. The environmental evaluation consisted of air sampling for potential lead emissions from solder and of work area dusts. In addition, the completion of a questionnaire, observation of work practices and noting of other details relevant to hazardous exposures were carried out. Lead concentrations in air were found to be well below the ACGIH TLV-TWA of 150 micrograms/m3. High lead concentrations were found in the work area dust samples. Exposure to high concentrations of lead could occur by ingestion as a result of neglect of basic hygiene precautions.

  15. Lead Exposure and Tremor among Older Men: The VA Normative Aging Study

    PubMed Central

    Power, Melinda C.; Sparrow, David; Spiro, Avron; Hu, Howard; Louis, Elan D.; Weisskopf, Marc G.

    2015-01-01

    Background: Tremor is one of the most common neurological signs, yet its etiology is poorly understood. Case–control studies suggest an association between blood lead and essential tremor, and that this association is modified by polymorphisms in the δ-aminolevulinic acid dehydrogenase (ALAD) gene. Objective: We aimed to examine the relationship between lead and tremor, including modification by ALAD, in a prospective cohort study, using both blood lead and bone lead—a biomarker of cumulative lead exposure. Methods: We measured tibia (n = 670) and patella (n = 672) bone lead and blood lead (n = 807) among older men (age range, 50–98 years) in the VA Normative Aging Study cohort. A tremor score was created based on an approach using hand-drawing samples. ALAD genotype was dichotomized as ALAD-2 carriers or not. We used linear regression adjusted for age, education, smoking, and alcohol intake to estimate the associations between lead biomarkers and tremor score. Results: In unadjusted analyses, there was a marginal association between quintiles of all lead biomarkers and tremor scores (p-values < 0.13), which did not persist in adjusted models. Age was the strongest predictor of tremor. Among those younger than the median age (68.9 years), tremor increased significantly with blood lead (p = 0.03), but this pattern was not apparent for bone lead. We did not see modification by ALAD or an association between bone lead and change in tremor score over time. Conclusion: Our results do not strongly support an association between lead exposure and tremor, and suggest no association with cumulative lead biomarkers, although there is some suggestion that blood lead may be associated with tremor among the younger men in our cohort. Citation: Ji JS, Power MC, Sparrow D, Spiro A III, Hu H, Louis ED, Weisskopf MG. 2015. Lead exposure and tremor among older men: the VA Normative Aging Study. Environ Health Perspect 123:445–450; http://dx.doi.org/10.1289/ehp.1408535

  16. The EPA's Human Exposure Research Program for Assessing Cumulative Risk in Communities

    EPA Science Inventory

    Communities are faced with challenges in identifying and prioritizing environmental issues, taking actions to reduce their exposures, and determining their effectiveness for reducing human health risks. Additional challenges include determining what scientific tools are available...

  17. The EPA's Human Exposure Research Program for Assessing Cumulative Risk in Communities

    EPA Science Inventory

    Communities are faced with challenges in identifying and prioritizing environmental issues, taking actions to reduce their exposures, and determining their effectiveness for reducing human health risks. Additional challenges include determining what scientific tools are available...

  18. METHODOLOGY FOR THE EVALUATION OF CUMULATIVE EPISODIC EXPOSURE TO CHEMICAL STRESSORS IN AQUATIC RISK ASSESSMENT.

    EPA Science Inventory

    An ecological risk assessment method was developed to evaluate the magnitude, duration, and episodic nature of chemical stressors on aquatic communities. The percent of an ecosystem's species at risk from a designated chemical exposure scenario is generated. In effects assessment...

  19. METHODOLOGY FOR THE EVALUATION OF CUMULATIVE EPISODIC EXPOSURE TO CHEMICAL STRESSORS IN AQUATIC RISK ASSESSMENT.

    EPA Science Inventory

    An ecological risk assessment method was developed to evaluate the magnitude, duration, and episodic nature of chemical stressors on aquatic communities. The percent of an ecosystem's species at risk from a designated chemical exposure scenario is generated. In effects assessment...

  20. Lead exposure and neurobehavior development in later infancy

    SciTech Connect

    Dietrich, K.N.; Succop, P.A.; Bornschein, R.L.; Hammond, P.B.; Buncher, C.R.; Berger, O. ); Krafft, K.M. )

    1990-11-01

    A prospective methodology was used to assess the neurobehavioral effects of fetal and postnatal lead exposure during the first 2 years of life. Lead was measured in whole blood prenatally in mothers and at quarterly intervals in the infant. Prenatal blood lead levels were low (mean = 8.0 {mu}g/dL). However, approximately 25% of the study infants had at least one serial blood lead level of 25 {mu}g/dL or higher during the second year of life. Multiple regression and structural equation analyses revealed statistically significant relationships between prenatal and neonatal blood lead level and 3- and 6-month Bayley Mental and/or Psychomotor Development Index. However, by 2 years of age, no statistically significant effects of prenatal or postnatal lead exposure on neurobehavioral development could be detected. Data consistent with the hypothesis that a postnatal neurobehavioral growth catch-up occurred in infants exposed fetally to higher levels of lead are presented.

  1. Lead exposure and neurobehavioral development in later infancy.

    PubMed Central

    Dietrich, K N; Succop, P A; Bornschein, R L; Krafft, K M; Berger, O; Hammond, P B; Buncher, C R

    1990-01-01

    A prospective methodology was used to assess the neurobehavioral effects of fetal and postnatal lead exposure during the first 2 years of life. Lead was measured in whole blood prenatally in mothers and at quarterly intervals in the infant. Prenatal blood lead levels were low (mean = 8.0 micrograms/dL). However, approximately 25% of the study infants had at least one serial blood lead level of 25 micrograms/dL or higher during the second year of life. Multiple regression and structural equation analyses revealed statistically significant relationships between prenatal and neonatal blood lead level and 3- and 6-month Bayley Mental and/or Psychomotor Development Index. However, by 2 years of age, no statistically significant effects of prenatal or postnatal lead exposure on neurobehavioral development could be detected. Data consistent with the hypothesis that a postnatal neurobehavioral growth catch-up occurred in infants exposed fetally to higher levels of lead are presented. PMID:2088739

  2. Study and models of total lead exposures of battery workers.

    PubMed

    Chavalitnitikul, C; Levin, L; Chen, L C

    1984-12-01

    In an attempt to establish a more realistic and reliable model for relating environmental exposure measurements to the biological indices of exposure, a study was undertaken to quantify the total sources of lead exposure among lead storage battery workers. In addition to the usual personal and area lead air sampling, quantitative and repeatable measurements of removable lead from work surfaces and the workers' hands and faces were obtained daily for ten consecutive work days in the pasting and battery assembly departments. Mathematical correlations of blood lead and zinc protoporphyrin (ZPP) levels as the dependent variable with the lead exposure sources were derived and demonstrated most strongly as log-log relationships. Statistical analyses by computer programming indicated that the airborne, hand, facial and work surface levels have a high degree of inter-correlation with a very significant positive individual correlation with blood lead levels and a somewhat lower correlation with ZPP. The results suggest that contaminated personal and work surfaces may play a more significant role in toxic occupational and environmental exposures, generally, than had heretofore been demonstrated or suspected.

  3. Site-specific lead exposure from lead pellet ingestion in sentinel mallards

    USGS Publications Warehouse

    Rocke, T.E.; Brand, C.J.; Mensik, John G.

    1997-01-01

    We monitored lead poisoning from the ingestion of spent lead pellets in sentinel mallards (Anas platyhrynchos) at the Sacramento National Wildlife Refuge (SNWR), Willows, California for 4 years (1986-89) after the conversion to steel shot for waterfowl hunting on refuges in 1986. Sentinel mallards were held in 1.6-ha enclosures in 1 hunted (P8) and 2 non-hunted (T19 and TF) wetlands. We compared site-specific rates of lead exposure, as determined by periodic measurement of blood lead concentrations, and lead poisoning mortality between wetlands with different lead pellet densities, between seasons, and between male and female sentinels. In 1986, the estimated 2-week rate of lead exposure was significantly higher (P < 0.005) in P8 (43.8%), the wetland with the highest density of spent lead pellets (>2,000,000 pellets/ha), than in those with lower densities of lead pellets, T19 (18.1%; 173,200 pellets/ha) and TF (0.9%; 15,750 pellets/ha). The probability of mortality from lead poisoning was also significantly higher (P < 0.01) in sentinel mallards enclosed in P8 (0.25) than T19 (0) and TF (0) in 1986 and remained significantly higher (P < 0.001) during the 4-year study. Both lead exposure and the probability of lead poisoning mortality in P8 were significantly higher (P < 0.001) in the fall of 1986 (43.8%; 0.25), before hunting season, than in the spring of 1987 (21.6%; 0.04), after hunting season. We found no significant differences in the rates of lead exposure or lead poisoning mortality between male and female sentinel mallards. The results of this study demonstrate that in some locations, lead exposure and lead poisoning in waterfowl will continue to occur despite the conversion to steel shot for waterfowl hunting.

  4. Site-specific lead exposure from lead pellet ingestion in sentinel mallards

    USGS Publications Warehouse

    Rocke, T.E.; Brand, C.J.; Mensik, John G.

    1997-01-01

    We monitored lead poisoning from the ingestion of spent lead pellets in sentinel mallards (Anas platyhrynchos) at the Sacramento National Wildlife Refuge (SNWR), Willows, California for 4 years (1986-89) after the conversion to steel shot for waterfowl hunting on refuges in 1986. Sentinel mallards were held in 1.6-ha enclosures in 1 hunted (P8) and 2 non-hunted (T19 and TF) wetlands. We compared site-specific rates of lead exposure, as determined by periodic measurement of blood lead concentrations, and lead poisoning mortality between wetlands with different lead pellet densities, between seasons, and between male and female sentinels. In 1986, the estimated 2-week rate of lead exposure was significantly higher (P < 0.005) in P8 (43.8%), the wetland with the highest density of spent lead pellets (>2,000,000 pellets/ha), than in those with lower densities of lead pellets, T19 (18.1%; 173,200 pellets/ha) and TF (0.9%; 15,750 pellets/ha). The probability of mortality from lead poisoning was also significantly higher (P < 0.01) in sentinel mallards enclosed in P8 (0.25) than T19 (0) and TF (0) in 1986 and remained significantly higher (P < 0.001) during the 4-year study. Both lead exposure and the probability of lead poisoning mortality in P8 were significantly higher (P < 0.001) in the fall of 1986 (43.8%; 0.25), before hunting season, than in the spring of 1987 (21.6%; 0.04), after hunting season. We found no significant differences in the rates of lead exposure or lead poisoning mortality between male and female sentinel mallards. The results of this study demonstrate that in some locations, lead exposure and lead poisoning in waterfowl will continue to occur despite the conversion to steel shot for waterfowl hunting.

  5. Cumulative systolic blood pressure exposure in relation to cognitive function in middle-aged and elderly adults: A prospective, population-based study.

    PubMed

    Liu, Jie; Huang, Yuling; Chen, Guojuan; Liu, Xiaoxue; Wang, Zhijun; Cao, Yibin; Li, Haitao; Song, Lu; Li, Chunhui; Zhao, Hualing; Chen, Shuohua; Wang, Yiming; Zhang, Ruiying; Wang, Anxin; Wu, Shouling

    2016-11-01

    The association between systolic blood pressure (SBP) and cognitive function is controversial in elderly adults. In addition, few studies focused on the cumulative effect of SBP. We aimed to investigate the association between cumulative SBP exposure and cognitive function among middle-aged and elderly adults.The analysis was based on the Asymptomatic Polyvascular Abnormalities Community (APAC) study. The primary predictor was the cumulative SBP calculated by consecutive SBP values measured through baseline (2006-2007) up to the fourth examination (2012-2013). The cognitive function was estimated by mini-mental state examination (MMSE) in the fourth examination. Linear regression and logistic regression analyses were used to investigate the association between cumulative SBP and cognitive function.Among 2211 participants (41.4% female, aged 40-94 years), 167 (7.55%) were diagnosed with cognitive impairment (MMSE score < 24). Higher cumulative exposure to SBP (per SD increment) was independently associated with poor cognitive performance after controlling for multiple factors (P < 0.001). We observed nondifferential association between men and women. However, higher cumulative SBP in the adults aged ≥60 years had a stronger association with poor cognitive performance compared with that in adults aged 40 to 60 years.Greater exposure to cumulative SBP is associated with worse cognitive performance among middle-aged and elderly adults. This association is similar between men and women, but stronger in elderly adults.

  6. Cumulative dietary exposure to a selected group of pesticides of the triazole group in different European countries according to the EFSA guidance on probabilistic modelling.

    PubMed

    Boon, Polly E; van Donkersgoed, Gerda; Christodoulou, Despo; Crépet, Amélie; D'Addezio, Laura; Desvignes, Virginie; Ericsson, Bengt-Göran; Galimberti, Francesco; Ioannou-Kakouri, Eleni; Jensen, Bodil Hamborg; Rehurkova, Irena; Rety, Josselin; Ruprich, Jiri; Sand, Salomon; Stephenson, Claire; Strömberg, Anita; Turrini, Aida; van der Voet, Hilko; Ziegler, Popi; Hamey, Paul; van Klaveren, Jacob D

    2015-05-01

    The practicality was examined of performing a cumulative dietary exposure assessment according to the requirements of the EFSA guidance on probabilistic modelling. For this the acute and chronic cumulative exposure to triazole pesticides was estimated using national food consumption and monitoring data of eight European countries. Both the acute and chronic cumulative dietary exposures were calculated according to two model runs (optimistic and pessimistic) as recommended in the EFSA guidance. The exposures obtained with these model runs differed substantially for all countries, with the highest exposures obtained with the pessimistic model run. In this model run, animal commodities including cattle milk and different meat types, entered in the exposure calculations at the level of the maximum residue limit (MRL), contributed most to the exposure. We conclude that application of the optimistic model run on a routine basis for cumulative assessments is feasible. The pessimistic model run is laborious and the exposure results could be too far from reality. More experience with this approach is needed to stimulate the discussion of the feasibility of all the requirements, especially the inclusion of MRLs of animal commodities which seem to result in unrealistic conclusions regarding their contribution to the dietary exposure.

  7. Parental occupational lead exposure and lead concentration of newborn cord blood

    SciTech Connect

    Wang, J.D.; Shy, W.Y.; Chen, J.S.; Yang, K.H.; Hwang, Y.H.

    1989-01-01

    The purpose of this study was to determine the influence of parental occupational lead exposure on the lead levels of newborn cord blood in the Taipei area. From September 1984 to June 1985, 5,000 pregnant women voluntarily participated in the study at the Taipei Municipal Maternal and Child Hospital. Each woman was interviewed regarding her and her husband's occupational exposures; 2,948 successfully delivered healthy newborns, and cord blood samples were obtained using Terumo Venoject, and 242 samples were analyzed by graphite furnace atomic absorption spectrometry using an Instrumentation Laboratory 251 instrument. Nine cord blood samples were from newborns with both parents exposed, 26 samples had maternal exposure only, 105 samples had paternal exposure only, and 102 were nonexposed. The results showed that the average lead level of cord blood with both parents exposed was 8.9 +/- 2.9 micrograms%, maternal exposure 9.0 +/- 3.8 micrograms%, paternal exposure 8.3 +/- 3.4 micrograms%, and 6.9 +/- 3.2 micrograms% in the nonexposed group. There were significant differences between the nonexposed and the maternal exposure groups, and also between the nonexposed and paternal exposure groups. All 26 maternal exposures were from lead soldering operations. Multivariate analysis revealed that, after control of father's exposure status, newborn cord blood lead level increased 0.27 micrograms% for each hour the mother spent on lead soldering during a normal working day, thus suggesting that soldering during pregnancy may be hazardous to newborns. Paternal contribution to the cord blood lead levels seemed to be through either working at home with the pregnant mother also at home or bringing work clothes home for laundering.

  8. Early childhood lead exposure and exceptionality designations for students.

    PubMed

    Miranda, Marie Lynn; Maxson, Pamela; Kim, Dohyeong

    2010-01-01

    The achievement gap continues to be an important educational issue, with disadvantaged groups exhibiting poorer school performance. Recently, literature has shown that even very low levels of early lead exposure affect cognitive and academic performance. As individuals at the lower end of the socioeconomic spectrum are more likely to be exposed to lead, this exposure may be an important contributor to the achievement gap. In this paper, we explore whether early childhood blood lead levels are associated with membership in exceptionality designation groups. In addition, we examine the racial and socioeconomic composition of these exceptional groups. Data from the North Carolina Childhood Lead Poisoning Prevention Program surveillance registry were linked at the individual child level to educational outcomes available through the North Carolina Education Research Data Center. Designation into exceptionality groups was obtained from the end-of-grade (EOG) data. Both standard bivariate and multivariate analyses were employed. Bivariate analyses indicate that blood lead levels and reading EOG scores differ by exceptionality, as well as by race and enrollment in free/reduced lunch. Logistic regression confirmed the relationship between blood lead levels and likelihood of exceptionality. Contextual factors - enrollment in the free/reduced lunch program, race, and parental education - are also significant with regard to exceptionality. This study demonstrates that early childhood lead exposure significantly influences the likelihood of being designated exceptional. These results provide additional evidence that early childhood lead exposure is a significant explanator of the achievement gap.

  9. Artificial Christmas trees: how real are the lead exposure risks?

    PubMed

    Maas, Richard P; Patch, Steven C; Pandolfo, Tamara J

    2004-12-01

    Exposure to lead has long been recognized as a major public health issue in the United States and other industrialized nations. The health risks associated with low lead levels mean that consumer products (such as those made from polyvinyl chloride [PVC] plastic, which often incorporates lead as a stabilizer) with even moderate lead exposure risks could be dangerous. The purpose of the experiments reported in this article was to test for lead exposure from artificial Christmas trees made of PVC, which are now present in an estimated 50 million U.S. households. The first phase of experimentation tested artificial Christmas trees in the laboratory for lead content in branches, lead transfer from hand contact, and lead dust levels under the tree. The second phase was based on a field-testing survey of households with artificial Christmas trees. Results from these experiments show that, while the average artificial Christmas tree does not present a significant exposure risk, in the worst-case scenarios a substantial health risk to young children is quite possible.

  10. Fluoride Concentration in Dentin of Exfoliated Primary Teeth as a Biomarker for Cumulative Fluoride Exposure

    PubMed Central

    dela Cruz, G.G.; Rozier, R.G.; Bawden, J.W.

    2008-01-01

    A biomarker for lifetime fluoride exposure would facilitate population-based research and policy making but currently does not exist. This study examined the suitability of primary tooth dentin as a biomarker by comparing dentin fluoride concentration and fluoride exposures. Ninety-nine children's exfoliated primary teeth were collected from 2 fluoridated and 2 fluoride-deficient communities in North Carolina. Coronal dentin was isolated by microdissection and fluoride concentration assayed using the microdiffusion, ion-specific electrode technique. Information on children's fluoride exposures since birth from drinking water, toothpaste, supplements, rinses, food and beverages was collected by a self-reported questionnaire administered to caregivers. Only a small portion of the variance (10%) in incisor dentin fluoride (mean 792, SD 402 mg/kg) was accounted for by the best linear regression model as evaluated by the adjusted R2. A moderate portion of the variance (60%) of molar dentin fluoride (mean 768, SD 489 mg/kg) was predicted by dietary fluoride supplement exposures, community of residence, and frequent tea consumption. Results for molars suggest that primary tooth dentin concentration may prove to be a satisfactory biomarker for fluoride exposure. PMID:18832828

  11. Vibration perception thresholds in workers with long term exposure to lead.

    PubMed

    Chuang, H Y; Schwartz, J; Tsai, S Y; Lee, M L; Wang, J D; Hu, H

    2000-09-01

    To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter. 217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT. VPT at a frequency of 220 Hz ranged from 6 to 100 (10(-2) g, or 0.098 m/s(2)) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 microgram/dl. Above this threshold it was estimated that each increase of 1 microgram/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10(-2) g) or 0.028 m/s(2) (at a frequency of 220 Hz) with other potential confounders held constant. This study suggests

  12. Multimedia lead exposure and associated risk assessment in Dhaka, Bangladesh

    SciTech Connect

    Sarwar, M.

    1998-12-31

    Motor vehicles consume the largest amount of leaded gasoline in Bangladesh. The number of vehicles and fuel consumption have increased significantly in recent years. These vehicles, which are believed to be the major sources of lead emissions in Dhaka, may cause an excessive level of lead exposure in children. The paper describes the results of a study conducted to determine risk associated with the multimedia lead exposure for children in Dhaka. Specifically, data related to lead content in air and soil in Dhaka were collected and used to estimate the blood lead levels in children. The Integrated Exposure Uptake Biokinetics Model, developed by the United States Environmental Protection Agency (USEPA), was used. Bangladesh is yet to adopt any blood lead standards. The results of the study indicated that the model predicted geometric blood lead levels in children in Dhaka are significantly below the blood lead standard recommended by the World Health Organization (WHO). It was also found that children in Dhaka are not expected to contain blood lead levels higher than the WHO recommended standard.

  13. Biochemical diagnosis of occupational exposure to lead toxicity

    SciTech Connect

    Somashekaraiah, B.V.; Venkaiah, B.; Prasad, A.R.K. )

    1990-02-01

    Lead has been shown to interfere with the biosynthesis of heme in a number of in vitro systems and in experimental animals as well as in human beings. Several steps of the heme biosynthetic chain are subject to the toxic effects of lead. ALA- dehydratase and Ferrochelatase, in particular, are two enzymes which are strongly inhibited by lead, leading to decreased heme synthesis, a constituent of hemoglobin. The inhibition of ALA dehydratase in the red blood cells by lead is generally recognized as the most sensitive index of the individuals exposure to this environmental chemical. Earlier reports show that the determination of blood lead content (Pb-B), zinc protoporphyrin levels and erythrocyte Aminolevulinic acid dehydratase (ALA.D) are widely used as biological indicators for lead toxicity. Hence, the aim of the present study was to screen for occupational exposure to lead in the workers of three different occupations and correlate their blood lead levels with erythrocyte ALA.D and total blood porphyrin content as biochemical indicators of lead exposure.

  14. Environmental lead exposure: a public health problem of global dimensions.

    PubMed Central

    Tong, S.; von Schirnding, Y. E.; Prapamontol, T.

    2000-01-01

    Lead is the most abundant of the heavy metals in the Earth's crust. It has been used since prehistoric times, and has become widely distributed and mobilized in the environment. Exposure to and uptake of this non-essential element have consequently increased. Both occupational and environmental exposures to lead remain a serious problem in many developing and industrializing countries, as well as in some developed countries. In most developed countries, however, introduction of lead into the human environment has decreased in recent years, largely due to public health campaigns and a decline in its commercial usage, particularly in petrol. Acute lead poisoning has become rare in such countries, but chronic exposure to low levels of the metal is still a public health issue, especially among some minorities and socioeconomically disadvantaged groups. In developing countries, awareness of the public health impact of exposure to lead is growing but relatively few of these countries have introduced policies and regulations for significantly combating the problem. This article reviews the nature and importance of environmental exposure to lead in developing and developed countries, outlining past actions, and indicating requirements for future policy responses and interventions. PMID:11019456

  15. A discriminant analysis of neuropsychological effect of low lead exposure.

    PubMed

    Boey, K W; Jeyaratnam, J

    1988-05-01

    The purpose of this study is to determine the contribution of psychological tests in discriminating neuropsychological effects of low lead exposure. The sample consists of 49 workers occupationally exposed to lead and a control group of 36 non-exposed workers. Their performance on various neuropsychological measures was subject to a discriminant analysis using the SPSS DISCRIMINANT subprogramme. The results indicate that simple reaction time, Digit Symbol (WAIS) and Trail-Making Test (Part A) provide the best combination of tests for the detection of neurotoxic effect of low lead exposure.

  16. Cumulative Resting Heart Rate Exposure and Risk of All-Cause Mortality: Results from the Kailuan Cohort Study

    PubMed Central

    Zhao, Quanhui; Li, Haibin; Wang, Anxin; Guo, Jin; Yu, Junxing; Luo, Yanxia; Chen, Shuohua; Tao, Lixin; Li, Yuqing; Li, Aiping; Guo, Xiuhua; Wu, Shouling

    2017-01-01

    The relationship between cumulative exposure to resting heart rate (cumRHR) and mortality remain unclear in the general population. In the Kailuan cohort study, resting heart rate (RHR) was repeatedly measured at baseline and at years 2 and 4 by electrocardiogram among 47,311 adults aged 48.70 ± 11.68. The cumRHR was defined as the summed average RHR between two consecutive examinations multiplied by the time interval between with two examinations [(beats/min) * year]. A higher RHR was defined as ≥80 beats/min, and the number of visits with a higher RHR was counted. During a median of 4.06 years of follow-up, a total of 1,025 participants died. After adjusting for major traditional cardiovascular risk factors and baseline RHR, the hazard ratio for the highest versus lowest quartile of cumRHR was 1.39 (95% CI: 1.07–1.81) for all-cause mortality. Each 1-SD increment in cumRHR was associated with a 37% (HR: 1.37, 95% CI: 1.23–1.52) increased risk of death and displayed a J-shaped relationship. Compared with no exposure, adults who had a higher RHR at all 3 study visits were associated with a 1.86-fold higher risk (95% CI: 1.33–2.61) of mortality. In summary, cumulative exposure to higher RHR is independently associated with an increased risk of mortality. PMID:28067310

  17. Environmental lead exposure to toll booth workers in Hong Kong

    SciTech Connect

    Tan, T.C.; Wong, L.T.L.; Lam, C.W.K.

    1988-01-01

    A survey of workers in the Lion Rock Tunnel toll booths was conducted, as they were regarded as a high risk group in lead exposure due to high density of vehicular traffic. The exposure of the workers to lead was determined by continuous sapling of air around the breathing zone of workers inside the booths. Blood lead concentration of 50 workers showed a mean of 0.65 {mu}mol/L and the mean urine lead concentration was 0.14 {mu}mol/L. Other tests, such as urinary amino-levulinic acid (ALA), erythrocyte zinc protoporphyrin (ZnPP) and hemoglobin concentration (Hb), were also preformed. The blood lead concentrations and other biological parameters of the toll-booth workers were acceptable and may be attributed to the recent legislation to lower the lead content in petrol and to the good preventive measures taken by the management.

  18. Reassessment of lead exposure in New Jersey using GIS technology.

    PubMed

    Guthe, W G; Tucker, R K; Murphy, E A; England, R; Stevenson, E; Luckhardt, J C

    1992-12-01

    In order to prevent children's exposure to lead, a variety of sources must be controlled. The New Jersey Department of Environmental Protection and Energy (NJDEPE) is using its Geographic Information System to identify areas within Newark, East Orange, and Irvington, New Jersey, where there may be greater environmental exposure to lead. Sensitive populations are identified through the U.S. Bureau of the Census information. Blood screening data provided by the New Jersey Department of Health (NJDOH) provide reported patterns of elevated blood lead in the study area. Comparisons of these spatial patterns will assist the NJDEPE in its soil sampling activities and lead exposure research, will provide information for public education, and will provide valuable information on sections of the study area where further screening and public education may be needed.

  19. IMPORTANT EXPOSURE FACTORS FOR CHILDREN AN ANALYSIS OF LABORATORY AND OBSERVATIONAL FIELD DATA CHARACTERIZING CUMULATIVE EXPOSURE TO PESTICIDES

    EPA Science Inventory

    In an effort to facilitate more realistic risk assessments that take into account unique childhood vulnerabilities to environmental toxicants, the U.S. EPA's National Exposure Research Laboratory (NERL) developed a framework for systematically identifying and addressing the most ...

  20. IMPORTANT EXPOSURE FACTORS FOR CHILDREN AN ANALYSIS OF LABORATORY AND OBSERVATIONAL FIELD DATA CHARACTERIZING CUMULATIVE EXPOSURE TO PESTICIDES

    EPA Science Inventory

    In an effort to facilitate more realistic risk assessments that take into account unique childhood vulnerabilities to environmental toxicants, the U.S. EPA's National Exposure Research Laboratory (NERL) developed a framework for systematically identifying and addressing the most ...

  1. Lead uptake and lead loss in the fresh water field crab, Barytelphusa guerini, on exposure to organic and inorganic lead

    SciTech Connect

    Tulasi, S.J.; Yasmeen, R.; Reddy, C.P.; Rao, J.V.R.

    1987-07-01

    Lead is a heavy metal which is widely used in paint industry, pigments, dyes, electrical components and electronics, plastic chemicals and in various other things. Since some of the lead salts are soluble in water, lead presents a potential threat to aquatic organisms. Studies dealing with invertebrates include those on mortality, growth and lead uptake in Lymnaea palustris and bioaccumulation of heavy metals in oysters and mussels. Little information exists regarding the effect of lead on the fresh water crustaceans. Hence the present investigation has been undertaken to study the uptake and loss of lead on exposure to subtoxic levels or organic and inorganic lead.

  2. Environmental urban lead exposure and blood lead levels in children of Mexico City.

    PubMed Central

    Romieu, I; Carreon, T; Lopez, L; Palazuelos, E; Rios, C; Manuel, Y; Hernandez-Avila, M

    1995-01-01

    Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics. PMID:8605853

  3. Environmental urban lead exposure and blood lead levels in children of Mexico City.

    PubMed

    Romieu, I; Carreon, T; Lopez, L; Palazuelos, E; Rios, C; Manuel, Y; Hernandez-Avila, M

    1995-11-01

    Lead contamination is now a leading public health problem in Mexico. However, there are few data on the lead content of various environmental sources, and little is known about the contribution of these sources to the total lead exposure in the population of children residing in Mexico City. We conducted a cross-sectional study in a random sample of 200 children younger than 5 years of age who lived in one of two areas of Mexico City. Environmental samples of floor, window, and street dust, paint, soil, water, and glazed ceramics were obtained from the participants' households, as well as blood samples and dirt from the hands of the children. Blood lead levels ranged from 1 to 31 micrograms/dl with a mean of 9.9 micrograms/dl (SD 5.8 micrograms/dl). Forty-four percent of the children 18 months of age or older had blood lead levels exceeding 10 micrograms/dl. The lead content of environmental samples was low, except in glazed ceramic. The major predictors of blood lead levels were the lead content of the glazed ceramics used to prepare children's food, exposure to airborne lead due to vehicular emission, and the lead content of the dirt from the children's hands. We conclude that the major sources of lead exposure in Mexico City could be controlled by adequate public health programs to reinforce the use of unleaded gasoline and to encourage production and use of unleaded cookware instead of lead-glazed ceramics.

  4. Prenatal lead exposure and childhood blood pressure and kidney function.

    PubMed

    Skröder, Helena; Hawkesworth, Sophie; Moore, Sophie E; Wagatsuma, Yukiko; Kippler, Maria; Vahter, Marie

    2016-11-01

    Exposure to lead, a common environmental pollutant, is known to cause cardiovascular and nephrotoxic effects in adults. Potential effects of early-life lead exposure on these functions are, however, less well characterized. To assess blood pressure and kidney function in preschool-aged children in relation to prenatal lead exposure. This prospective study in rural Bangladesh measured children's systolic and diastolic blood pressure in triplicate at the follow-up at 4.5±0.11 years. Their kidney function was assessed by the estimated glomerular filtration rate (eGFR), calculated based on serum cystatin C concentrations, and by kidney volume, measured by sonography. Exposure to lead was assessed by concentrations in the mothers' blood (erythrocyte fraction; Ery-Pb) in gestational weeks (GW) 14 and 30, the effects of which were evaluated separately in multivariable-adjusted linear regression analyses. We found no associations between maternal exposure to lead [n~1500 for GW14 and 700 for GW30] and children's blood pressure or eGFR. However, we found an inverse association between late gestation lead and kidney volume, although the sample size was limited (n=117), but not with early gestation lead (n=573). An increase of 85µg/kg in Ery-Pb (median concentration at GW30) was associated with a 6.0cm(3)/m(2) decrease in kidney volume (=0.4SD; p=0.041). After stratifying on gender, there seemed to be a somewhat stronger association in girls. Prenatal lead exposure may cause long-lasting effects on the kidney. This warrants follow-up studies in older children, as well as additional studies in other populations. Copyright © 2016. Published by Elsevier Inc.

  5. The intersection of aggregate-level lead exposure and crime.

    PubMed

    Boutwell, Brian B; Nelson, Erik J; Emo, Brett; Vaughn, Michael G; Schootman, Mario; Rosenfeld, Richard; Lewis, Roger

    2016-07-01

    Childhood lead exposure has been associated with criminal behavior later in life. The current study aimed to analyze the association between elevated blood lead levels (n=59,645) and crime occurrence (n=90,433) across census tracts within St. Louis, Missouri. Longitudinal ecological study. Saint Louis, Missouri. Blood lead levels. Violent, Non-violent, and total crime at the census tract level. Spatial statistical models were used to account for the spatial autocorrelation of the data. Greater lead exposure at the census-tract level was associated with increased violent, non-violent, and total crime. In addition, we examined whether non-additive effects existed in the data by testing for an interaction between lead exposure and concentrated disadvantage. Some evidence of a negative interaction emerged, however, it failed to reach traditional levels of statistical significance (supplementary models, however, revealed a similar negative interaction that was significant). More precise measurements of lead exposure in the aggregate, produced additional evidence that lead is a potent predictor of criminal outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

  6. Exposure of migrant bald eagles to lead in prairie Canada.

    PubMed

    Miller, M J; Wayland, M E; Bortolotti, G R

    2001-01-01

    The prevalence of elevated exposure to lead was assessed in a migrant population of bald eagles (Haliaeetus leucocephalus) at a waterfowl staging area in the southern portion of the Canadian prairies, from September to November, 1992-1995. Of 103 eagles, 8% exhibited blood lead (PbB) concentrations suggestive of elevated exposure to lead (> or = 0.200 microgram ml-1 wet wt.). PbB concentrations in eagles from the study area ranged from < 0.01 to 0.585 microgram ml-1, while those of nestling eagles from a reference site indicated normal or background exposure (< 0.01 microgram ml-1). No differences in the prevalence of elevated exposure were detected among genders or age classes (0.5- and > or = 1.5-year-old birds) (P > 0.05). The prevalence of elevated exposure was significantly greater in November than in October (21.7 vs. 3.8%) (all years: chi 2Y = 5.75, P = 0.017). Eagles with shotshell pellets in the digestive tract did not have accompanying high PbB concentrations. The prevalence of elevated lead exposure in this study was low in comparison to other areas in North America. Potential biases in the trapping technique as they relate to interpreting the results are addressed.

  7. Exposure to lead and human health in the Czech Republic.

    PubMed

    Bláha, K; Bencko, V; Cikrt, M

    1996-12-01

    The aim of presented review is to address the most relevant issues related to the health effects caused by the human exposure to lead, as they have been recognized in Czech Republic in the period of 1992-1994 within the framework of the National Integrated Programme on Environment and Health (NIPEH) approved in 1992 and supported by WHO-European Centre for Environment and Health (WHO-ECEH), Bilthoven, The Netherlands and by the Government of the Netherlands. Basic sources of environment exposure to lead are identified and the fate of lead in the individual compartments of the environment is discussed. Relevant methods used for the exposure evaluation are summarized and the highest-risk group of population is defined. Attention is being paid to the effects of the long-term exposure to low lead levels, while other exposure settings are intentionally omitted. Interventional measures developed in the Czech Republic in attempt to reduce the environmental exposure are introduced. Instead of presenting specific data, current state-of-art and general trends are presented; list of references tries to combine the internationally recognized studies with those coming from national sources.

  8. Window renovation and exposure to lead--an observational study.

    PubMed

    Mason, Howard; Gallagher, Frank; Sen, Dil

    2005-12-01

    Renovation of windows in old houses has recently established itself as an industry. A recognizable occupational lead exposure exists, which has not been studied previously. To compare lead exposure amongst window renovators with other groups of lead-exposed workers. Using blood lead results measured at the Health and Safety Laboratory (HSL), Sheffield, comparisons were made between three cohorts: window renovation workers, all male workers monitored by HSL during the period 1999-2001 and 63 male subjects involved in chemical paint-stripping of wood. Both the window renovation and the wood-stripping cohorts show significantly higher blood lead distributions than the 'all workers' cohort (P < 0.001). A similar pattern was also found for comparison of the prevalence of subjects above the UK suspension level of 60 microg/dl (2.89 microM) (window renovation, P < 0.001; wood-stripping, P < 0.0001). Blood lead results at or above the suspension level in wood-strippers were significantly higher compared to window renovators (P = 0.034). Window renovation is shown to present a potential for significant lead exposure, and suspension from work under The Control of Lead at Work Regulations 2002. Two groups of risk factors predominate: the well-documented potential for release of lead from old paint, and the peripatetic nature of the work.

  9. Occupational exposure to airborne lead in Brazilian police officers.

    PubMed

    Rocha, Ernesto Díaz; Sarkis, Jorge E Souza; Carvalho, Maria de Fátima H; Santos, Gerson Vechio Dos; Canesso, Claudemir

    2014-07-01

    Shooting with lead-containing ammunition in indoor firing ranges is a known source of lead exposure in adults. Police officers may be at risk of lead intoxication when regular training shooting exercises are yearly mandatory to law enforcement officers. Effects on health must be documented, even when low-level elemental (inorganic) lead exposure is detected. Forty police officers (nineteen cadets and twenty-one instructors) responded to a questionnaire about health, shooting habits, and potential lead exposure before a training curse. Blood samples were collected and analyzed for blood lead level (BLL) before and after a three days training curse. The mean BLL for the instructors' group was 5.5 μg/dL ± 0.6. The mean BLL for the cadets' group before the training was 3.3 μg/dL ± 0.15 and after the training the main BLL was 18.2 μg/d L± 1.5. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). All the participants in the training curse had significantly increased BLL (mean increment about 15 μg/dL) after the three days indoor shooting season. In conclusion, occupational lead exposure in indoor firing ranges is a source of lead exposure in Brazilian police officers, and appears to be a health risk, especially when heavy weapons with lead-containing ammunition are used in indoor environments during the firing training seasons. Copyright © 2013 Elsevier GmbH. All rights reserved.

  10. Lead exposure from the use of Lawsonia inermis (henna) in temporary paint-on-tattooing and hair dying.

    PubMed

    Jallad, Karim N; Espada-Jallad, Cyntia

    2008-07-01

    This study reports the evaluation of a number of spectroscopic techniques used in identifying and quantifying the presence of lead in twelve commercial and traditional henna samples. The lead levels found in henna were low with concentrations ranging from 2.29 ppm to 65.98 ppm. Henna is used as a traditional cosmetic and remedy in the Middle East, Far East, and North Africa. The very low concentrations of lead measured in these henna samples were reassuring; however, the cumulative effects of prolonged lead exposure may be of concern. Thus, the use of henna especially among children may constitute a public health risk.

  11. Using fractional polynomials to model the effect of cumulative duration of exposure on outcomes: applications to cohort and nested case-control designs

    PubMed Central

    Austin, Peter C; Park-Wyllie, Laura Y; Juurlink, David N

    2014-01-01

    Purpose Determining the nature of the relationship between cumulative duration of exposure to an agent and the hazard of an adverse outcome is an important issue in environmental and occupational epidemiology, public health and clinical medicine. The Cox proportional hazards regression model can incorporate time-dependent covariates. An important class of continuous time-dependent covariates is that denoting cumulative duration of exposure. Methods We used fractional polynomial methods to describe the association between cumulative duration of exposure and adverse outcomes. We applied these methods in a cohort study to examine the relationship between cumulative duration of use of the antiarrhythmic drug amiodarone and the risk of thyroid dysfunction. We also used these methods with a conditional logistic regression model in a nested case-control study to examine the relationship between cumulative duration of use of bisphosphonate medication and the risk of atypical femur fracture. Results Using a cohort design and a Cox proportional hazards model, we found a non-linear relationship between cumulative duration of use of the antiarrhythmic drug amiodarone and the risk of thyroid dysfunction. The risk initially increased rapidly with increasing cumulative use. However, as cumulative duration of use increased, the rate of increase in risk attenuated and eventually levelled off. Using a nested case-control design and a conditional logistic regression model, we found evidence of a linear relationship between duration of use of bisphosphonate medication and risk of atypical femur fractures. Conclusions Fractional polynomials allow one to model the relationship between cumulative duration of medication use and adverse outcomes. PMID:24664670

  12. Education, occupation, noise exposure history and the 10-yr cumulative incidence of hearing impairment in older adults.

    PubMed

    Cruickshanks, Karen J; Nondahl, David M; Tweed, Ted S; Wiley, Terry L; Klein, Barbara E K; Klein, Ronald; Chappell, Rick; Dalton, Dayna S; Nash, Scott D

    2010-06-01

    The purpose of this study was to determine the 10-yr cumulative incidence of hearing impairment and associations of education, occupation and noise exposure history with the incidence of hearing impairment in a population-based cohort study of 3753 adults ages 48-92 yr at the baseline examinations during 1993-1995 in Beaver Dam, WI. Hearing thresholds were measured at baseline, 2.5 yr-, 5 yr-, and 10-yr follow-up examinations. Hearing impairment was defined as a pure-tone average (PTA)>25 dB HL at 500, 1000, 2000, and 4000 Hz. Demographic characteristics and occupational histories were obtained by questionnaire. The 10-yr cumulative incidence of hearing impairment was 37.2%. Age (5 yr; Hazard Ratio (HR)=1.81), sex (M vs W; HR=2.29), occupation based on longest held job (production/operations/farming vs others; HR=1.34), marital status (unmarried vs married; HR=1.29) and education (<16 vs 16+yr; HR=1.40) were associated with the 10 yr incidence. History of noisy jobs was not associated with the 10-yr incidence of hearing impairment. The risk of hearing impairment was high, with women experiencing a slightly later onset. Markers of socioeconomic status were associated with hearing impairment, suggesting that hearing impairment in older adults may be associated with modifiable lifestyle and environmental factors, and therefore, at least partially preventable.

  13. Take home lead exposure in children of oil field workers.

    PubMed

    Khan, Fahad

    2011-06-01

    Childhood lead poisoning is a major, preventable environmental health problem. While residential lead-based paint and lead contaminated dust and soil are the most common sources of childhood lead poisoning, children can also be at risk if they live with an adult with a job or hobby that involves exposure to lead. Currently, the Oklahoma Childhood Lead Poisoning Prevention Program (OCLPPP) has a small number of cases of "take home" lead exposure in children of oil field workers. These workers may come in contact with a threading compound, "pipe dope" that can contain large amounts of lead. Workers handling this product may be exposed to lead by not following safety instructions. Additionally workers may not be provided the facilities to shower and change out of the contaminated clothing before leaving the work location. The OCLPPP recommends employers and worksites should consider effective alternative options like lead free biodegradable pipe dopes or dope free connections to prevent workers and their families from adverse health effects associated with lead.

  14. Breast milk and lipid intake distributions for assessing cumulative exposure and risk.

    PubMed

    Arcus-Arth, Amy; Krowech, Gail; Zeise, Lauren

    2005-07-01

    Breast milk consumption is the primary route of infant exposure to certain lipophilic toxicants that have accumulated over decades in maternal adipose tissue, as well as to less persistent toxicants from maternal exposure during lactation. Such infant exposures occur at a time of rapid growth and development when susceptibility to certain toxicants can be greatest. Breast milk and lipid intake rates are presented for the 0-6 and 0-12 month age periods for infants fed according to the American Academy of Pediatrics' current recommendations (exclusive breast-feeding for 0-6 months and continued breast-feeding to 12 months). Intake rates are normalized to infant bodyweight to account for the covariance of consumption and bodyweight. Frequency distributions describe the population variability in intake. For age 0-12 months, daily average milk intake is 100.7 +/- 22.7 g/kg day (mean +/- SD), with a 95th percentile of 153.5 g/kg day. Breast milk intake distributions are also developed for infants exclusively breast-fed (no significant calories from non-breast milk sources) over their first year, and for the entire (nursing and non-nursing) infant population. For short-term exposures, intake can be derived from the regression equation presented here. Lipid intake estimated assuming a 4% lipid content (current risk assessment practice) is compared and found comparable to that derived from measured lipid content. The national trend of increased breast-feeding found in surveys further supports including the breast milk pathway in risk assessment.

  15. Lead exposure from backyard chicken eggs: a public health risk?

    PubMed

    Bautista, Adrienne C; Puschner, Birgit; Poppenga, Robert H

    2014-09-01

    Although the USA has made significant strides in reducing lead exposure, new and emerging sources are raising cause for public concern. Recent reports of finding lead in eggs from chickens raised in urban gardens has highlighted the need to consider the potential health risks of consuming eggs from backyard chickens. Following the detection of 0.33 μg/g lead in the edible portion of eggs submitted for lead analysis from a backyard chicken owner, further investigation was conducted to determine the source and extent of lead exposure in the flock. Several birds, almost two dozen eggs, and environmental samples were submitted to the California Animal Health and Food Safety Laboratory for further testing. Lead was detected in the blood, liver, kidney, and bone at varying concentrations in all birds but was not detected in the muscle tissue. All egg shells contained detectable amounts of lead, while only a little over half of the edible portion of the eggs contained lead. The detected concentrations in the edible portion approached or exceeded the recommended threshold of lead consumption per day that should not be exceeded by young children if a child consumed one average-sized egg. Peeling paint from a wooded structure adjacent to the flock's coop was the likely lead source containing 3,700 μg/g lead. Thus, removal of the chickens from the source and periodic testing of eggs for lead were recommended. This case illustrates the need for consumers and health care workers to be aware of potential sources for lead exposure such as backyard chickens.

  16. Reducing purposeful headers from goal kicks and punts may reduce cumulative exposure to head acceleration.

    PubMed

    Caccese, Jaclyn B; Lamond, Lindsey C; Buckley, Thomas A; Kaminski, Thomas W

    2016-01-01

    The purpose of this study was to measure peak linear and rotational head acceleration in women's collegiate soccer and explore the variations in acceleration across different strategic scenarios. Game videos from 14 games were used to identify the strategic scenario in which the athlete headed the ball. Strategic scenarios included: bounce, secondary header, punt, throw-in, goal kick, corner kick, and kick. Peak linear and rotational accelerations were measured using the Smart Impact Monitor (Triax Technologies Inc., Norwalk, CT). Goal kick (38.8 ± 19.4 g, p = 0.001, ß = 8.9; 9.3 ± 3.9 krad/s(2), p = 0.004, ß = 1.9) and punt (36.0 ± 15.1 g, p = 0.055, ß = 6.3; 10.1 ± 4.8 krad/s(2), p = 0.002, ß = 2.5) impacts resulted in higher linear and rotational head accelerations than the base variable, kick (30.0 ± 19.5 g; 7.5 ± 4.1 krad/s(2)). This suggests that limiting headers from goal kicks and punts in younger athletes who are still learning proper heading technique may limit cumulative linear and rotational accelerations.

  17. Cumulative exposure to work-related traumatic events and current post-traumatic stress disorder in New York City's first responders.

    PubMed

    Geronazzo-Alman, Lupo; Eisenberg, Ruth; Shen, Sa; Duarte, Cristiane S; Musa, George J; Wicks, Judith; Fan, Bin; Doan, Thao; Guffanti, Guia; Bresnahan, Michaeline; Hoven, Christina W

    2017-04-01

    Cumulative exposure to work-related traumatic events (CE) is a foreseeable risk for psychiatric disorders in first responders (FRs). Our objective was to examine the impact of work-related CE that could serve as predictor of posttraumatic stress disorder (PTSD) and/or depression in FRs. Cross-sectional examination of previous CE and past-month PTSD outcomes and depression in 209 FRs. Logistic (probable PTSD; probable depression) and Poisson regressions (PTSD score) of the outcomes on work-related CE indexes, adjusting for demographic variables. Differences across occupational groups were also examined. Receiver operating characteristic analysis determined the sensitivity and specificity of CE indexes. All indexes were significantly and differently associated with PTSD; associations with depression were non-significant. The index capturing the sheer number of different incidents experienced regardless of frequency ('Variety') showed conceptual, practical and statistical advantages compared to other indexes. In general, the indexes showed poor to fair discrimination accuracy. Work-related CE is specifically associated with PTSD. Focusing on the variety of exposures may be a simple and effective strategy to predict PTSD in FRs. Further research on sensitivity and specificity of exposure indexes, preferably examined prospectively, is needed and could lead to early identification of individuals at risk. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. The cultural parameters of lead poisoning: A medical anthropologist's view of intervention in environmental lead exposure

    SciTech Connect

    Trotter, R.T. II )

    1990-11-01

    This article identifies four culturally shaped sources of lead exposure in human societies: modern and historic technological sources; food habits; culturally defined health beliefs; and beauty practices. Examples of these potential sources of lead poisoning are presented from current cultures. They include the use of lead-glazed cooking pottery in Mexican-American households; folk medical use of lead in Hispanic, Arabic, South Asian, Chinese, and Hmong communities; as well as the use of lead as a cosmetic in the Near East, Southeast Asia, and South Asia. Four interacting cultural conditions that create barriers to the reduction of lead exposure and lead poisoning are identified and discussed. These are knowledge deficiencies, communication resistance, cultural reinterpretations, and incongruity of explanatory models.

  19. The cultural parameters of lead poisoning: a medical anthropologist's view of intervention in environmental lead exposure.

    PubMed Central

    Trotter, R T

    1990-01-01

    This article identifies four culturally shaped sources of lead exposure in human societies: modern and historic technological sources: food habits; culturally defined health beliefs; and beauty practices. Examples of these potential sources of lead poisoning are presented from current cultures. They include the use of lead-glazed cooking pottery in Mexican-American households; folk medical use of lead in Hispanic, Arabic, South Asian, Chinese, and Hmong communities; as well as the use of lead as a cosmetic in the Near East, Southeast Asia, and South Asia. Four interacting cultural conditions that create barriers to the reduction of lead exposure and lead poisoning are identified and discussed. These are knowledge deficiencies, communication resistance, cultural reinterpretations, and incongruity of explanatory models. PMID:2088759

  20. Lead exposure in firearms instructors of the Italian State Police.

    PubMed

    Di Lorenzo, L; Borraccia, V; Corfiati, Marisa; Mantineo, G A; Caciari, Tiziana; Marino, Marina; Soleo, L

    2010-01-01

    Several studies evaluated exposure to lead in relatively small groups of firearms instructors and shooters, mainly operating at indoor ranges. To assess the levels of lead exposure in a large sample of firearms instructors of the Italian State Police (SP) operating at either indoor or outdoor ranges. A crosssectional study was conducted in firearms instructors working in indoor (No. 188) and outdoor (No. 188) ranges compared with 170 foodplant workers. The personal and work characteristics and current blood lead (Pb-B) levels were evaluated The concentrations of environmental lead (Pb-E) were measured using personal samplers in 6 indoor and 6 outdoor firing ranges. The Pb-B levels in the two groups of firearms instructors were well below the ACGIH BEI, but significantly higher than in food plant workers. In the entire study sample the Pb-B level was seen to be influenced by age and job group. An excess risk of having Pb-B >100 microg/l was found in indoor range instructors and in those with greater job seniority. Pb-E <25 pg/m3 was measured in all the firing ranges examined. The low Pb-B and Pb-E levels assessed are the result of primary and secondary prevention interventions carried out over the years by the Italian State Police. The current Pb-B levels also seemed to be poorly influenced by higher past environmental and/or occupational lead exposure. In fact a certain number of firearms instructors, mainly operating at indoor ranges and with greater job seniority, had Pb-B levels consistent with occupational exposure to lead. Environmental and biological monitoring of lead exposure and specific health surveillance are therefore still necessary in this job group topreventpossible adverse health effects of lead even at low doses.

  1. Calibrating a population-based job-exposure matrix using inspection measurements to estimate historical occupational exposure to lead for a population-based cohort in Shanghai, China

    PubMed Central

    Koh, Dong-Hee; Bhatti, Parveen; Coble, Joseph B.; Stewart, Patricia A; Lu, Wei; Shu, Xiao-Ou; Ji, Bu-Tian; Xue, Shouzheng; Locke, Sarah J.; Portengen, Lutzen; Yang, Gong; Chow, Wong-Ho; Gao, Yu-Tang; Rothman, Nathaniel; Vermeulen, Roel; Friesen, Melissa C.

    2012-01-01

    The epidemiologic evidence for the carcinogenicity of lead is inconsistent and requires improved exposure assessment to estimate risk. We evaluated historical occupational lead exposure for a population-based cohort of women (n=74,942) by calibrating a job-exposure matrix (JEM) with lead fume (n=20,084) and lead dust (n=5,383) measurements collected over four decades in Shanghai, China. Using mixed-effect models, we calibrated intensity JEM ratings to the measurements using fixed-effects terms for year and JEM rating. We developed job/industry-specific estimates from the random-effects terms for job and industry. The model estimates were applied to subjects’ jobs when the JEM probability rating was high for either job or industry; remaining jobs were considered unexposed. The models predicted that exposure increased monotonically with JEM intensity rating and decreased 20–50-fold over time. The cumulative calibrated JEM estimates and job/industry-specific estimates were highly correlated (Pearson correlation=0.79–0.84). Overall, 5% of the person-years and 8% of the women were exposed to lead fume; 2% of the person-years and 4% of the women were exposed to lead dust. The most common lead-exposed jobs were manufacturing electronic equipment. These historical lead estimates should enhance our ability to detect associations between lead exposure and cancer risk in future epidemiologic analyses. PMID:22910004

  2. Calibrating a population-based job-exposure matrix using inspection measurements to estimate historical occupational exposure to lead for a population-based cohort in Shanghai, China.

    PubMed

    Koh, Dong-Hee; Bhatti, Parveen; Coble, Joseph B; Stewart, Patricia A; Lu, Wei; Shu, Xiao-Ou; Ji, Bu-Tian; Xue, Shouzheng; Locke, Sarah J; Portengen, Lutzen; Yang, Gong; Chow, Wong-Ho; Gao, Yu-Tang; Rothman, Nathaniel; Vermeulen, Roel; Friesen, Melissa C

    2014-01-01

    The epidemiologic evidence for the carcinogenicity of lead is inconsistent and requires improved exposure assessment to estimate risk. We evaluated historical occupational lead exposure for a population-based cohort of women (n=74,942) by calibrating a job-exposure matrix (JEM) with lead fume (n=20,084) and lead dust (n=5383) measurements collected over four decades in Shanghai, China. Using mixed-effect models, we calibrated intensity JEM ratings to the measurements using fixed-effects terms for year and JEM rating. We developed job/industry-specific estimates from the random-effects terms for job and industry. The model estimates were applied to subjects' jobs when the JEM probability rating was high for either job or industry; remaining jobs were considered unexposed. The models predicted that exposure increased monotonically with JEM intensity rating and decreased 20-50-fold over time. The cumulative calibrated JEM estimates and job/industry-specific estimates were highly correlated (Pearson correlation=0.79-0.84). Overall, 5% of the person-years and 8% of the women were exposed to lead fume; 2% of the person-years and 4% of the women were exposed to lead dust. The most common lead-exposed jobs were manufacturing electronic equipment. These historical lead estimates should enhance our ability to detect associations between lead exposure and cancer risk in the future epidemiologic analyses.

  3. Tremor secondary to neurotoxic exposure: mercury, lead, solvents, pesticides.

    PubMed

    Lucchini, Roberto G; Hashim, Dana

    2015-01-01

    Lead, mercury, solvents, and pesticide exposures are common in certain occupations and may cause nervous system dysfunction. Tremors may be the herald manifestation among a constellation of acute toxicity signs and symptoms. However, since tremors may also be the only sign on clinical presentation and since tremors also occur in other diseases, relating tremors to a specific occupational exposure can be challenging. Diagnosis of tremor etiology must be based on other findings on physical exam, laboratory results, and/or imaging. Discerning whether the tremor resulted from the occupational environment versus other etiologies requires knowledge of potential exposure sources, additional detail in history taking, and support of other health and industrial professionals. Reduction or removal from the exposure source remains the key first step in treating patients suffering from tremor that had resulted from occupational exposure toxicity.

  4. Pediatric lead exposure from imported Indian spices and cultural powders.

    PubMed

    Lin, Cristiane Gurgel; Schaider, Laurel Anne; Brabander, Daniel Joseph; Woolf, Alan David

    2010-04-01

    Significant lead poisoning has been associated with imported nonpaint products. To describe cases of pediatric lead intoxication from imported Indian spices and cultural powders, determine lead concentrations in these products, and predict effects of ingestion on pediatric blood lead levels (BLLs). Cases and case-study information were obtained from patients followed by the Pediatric Environmental Health Center (Children's Hospital Boston). Imported spices (n = 86) and cultural powders (n = 71) were analyzed for lead by using x-ray fluorescence spectroscopy. The simple bioaccessibility extraction test was used to estimate oral bioavailability. The integrated exposure uptake biokinetic model for lead in children was used to predict population-wide geometric mean BLLs and the probability of elevated BLLs (>10 microg/dL). Four cases of pediatric lead poisoning from Indian spices or cultural powders are described. Twenty-two of 86 spices and foodstuff products contained >1 microg/g lead (for these 22 samples, mean: 2.6 microg/g [95% confidence interval: 1.9-3.3]; maximum: 7.6 microg/g). Forty-six of 71 cultural products contained >1 microg/g lead (for 43 of these samples, mean: 8.0 microg/g [95% confidence interval: 5.2-10.8]; maximum: 41.4 microg/g). Three sindoor products contained >47% lead. With a fixed ingestion of 5 microg/day and 50% bioavailability, predicted geometric mean BLLs for children aged 0 to 4 years increased from 3.2 to 4.1 microg/dL, and predicted prevalence of children with a BLL of >10 microg/dL increased more than threefold (0.8%-2.8%). Chronic exposure to spices and cultural powders may cause elevated BLLs. A majority of cultural products contained >1 microg/g lead, and some sindoor contained extremely high bioaccessible lead levels. Clinicians should routinely screen for exposure to these products.

  5. Diurnal cortisol rhythms in youth from risky families: effects of cumulative risk exposure and variation in the serotonin transporter gene-linked polymorphic region (5-HTTLPR) [corrected].

    PubMed

    Willner, Cynthia J; Morris, Pamela A; McCoy, Dana Charles; Adam, Emma K

    2014-11-01

    Building on research on cumulative risk and psychopathology, this study examines how cumulative risk exposure is associated with altered diurnal cortisol rhythms in an ethnically diverse, low-income sample of youth. In addition, consistent with a diathesis-stress perspective, this study explores whether the effect of environmental risk is moderated by allelic variation in the promoter region of the serotonin transporter gene-linked polymorphic region (5-HTTLPR). Results show that youth with greater cumulative risk exposure had flatter diurnal cortisol slopes, regardless of 5-HTTLPR genotype. However, the association of cumulative risk with average cortisol output (area under the curve [AUC]) was moderated by the 5-HTTLPR genotype. Among youth homozygous for the long allele, greater cumulative risk exposure was associated with lower cortisol AUC, driven by significant reductions in cortisol levels at waking. In contrast, there was a trend-level association between greater cumulative risk and higher cortisol AUC among youth carrying the short allele, driven by a trend-level increase in bedtime cortisol levels. Findings are discussed with regard to the relevance of dysregulated diurnal cortisol rhythms for the development of psychopathology and the implications of genetically mediated differences in psychophysiological adaptations to stress.

  6. Environmental contamination and human exposure to lead in Brazil.

    PubMed

    Paoliello, Monica M B; De Capitani, Eduardo M

    2005-01-01

    Adverse effects caused by environmental lead pollution are well recognized. Being a widespread agent in the environment and a major harmful element to organic systems, mostly to children, lead has been investigated all over the world, aiming to improve measures regarding its control. The purpose of this chapter is to present a review of the situation of production, uses, assessment of exposure, and adverse effects from environmental lead contamination in Brazil. It also presents aspects of Brazilian legislation setting up maximum permissible levels of lead in several environmental compartments such as surface and drinking water, soils, sediment, urban air, and also in commercially sold food, vegetables, fish, and meat, in an effort to control industrial emissions. Epidemiological investigations on children's lead exposure around industrial and mining areas are revised, showing that many situations where lead contamination is potentially present still need to be addressed by governmental agencies. In Brazil, lead was withdrawn from gasoline by the end of the 1980s, and the last lead mining and primary smelting plant was closed in 1995, leaving residual environmental lead contamination, which has recently been investigated using a multidisciplinary approach. Nevertheless, there are hundreds of small secondary battery recycling plants all over the country, running smelting facilities that produce local urban areas of lead contamination.

  7. Assessment of soil lead exposure in children in Shenyang, China.

    PubMed

    Ren, H M; Wang, J D; Zhang, X L

    2006-11-01

    Soil lead pollution is serious in Shenyang, China. The paper brings together the soil work, the bioaccessibility, and the blood lead data to assess the soil lead exposure in children in Shenyang, China. Approximately 15.25% of the samples were above China Environment Protection Agency guideline concentration for soil Pb to protect human from health risk (350 mgkg(-1)). Pb concentrations varied among use scenarios. The main lead contamination sources are industry emission and automobile exhaust. Bioaccessibility also varied among use scenarios. Children, who ingested soil from industrial area, public parks, kindergarten playground, and commercial area, are more susceptible to soil lead toxicity. The industrial area soil samples presented higher bioaccessibility compared to the other use scenario soil samples contaminated by automobile exhaust. The result also suggested a most significant linear relationship between the level of Pb contamination and the amount of Pb mobilized from soil into ingestion juice. Soil pH seemed to have insignificant influence on bioaccessibility in the present study. Bioaccessibility was mainly controlled by other factors that are not investigated in this study. A linear relationship between children blood lead and soil intestinal bioaccessibility was present in the study. Children who are 4-5 years old are more likely to demonstrate the significant relationship between soil lead bioaccessibility and blood lead as their behaviors place them at greatest risk of soil lead toxicity, and their blood lead levels are more likely to represent recent exposure.

  8. OSHA lead in construction compliance directive: Exposure assessment

    SciTech Connect

    Vernon, L.S.

    1994-07-01

    This article is the second in a series that reviews the Occupational Health and Safety Administration (OSHA) Instruction CPL 2-2.58, a compliance directive for 29 CFR 1926.62, Lead Exposure in Construction. The OSHA document is intended to provide guidance to those charged with field enforcement of the lead regulation; however, it also provides vital information to those in industry who must comply with the regulation. This month, the requirements for compliance with 29 CFR 1926.62 (d) Exposure Assessment are discussed.

  9. Occupational Lead Exposure and Associations with Selected Cancers: The Shanghai Men’s and Women’s Health Study Cohorts

    PubMed Central

    Liao, Linda M.; Friesen, Melissa C.; Xiang, Yong-Bing; Cai, Hui; Koh, Dong-Hee; Ji, Bu-Tian; Yang, Gong; Li, Hong-Lan; Locke, Sarah J.; Rothman, Nathaniel; Zheng, Wei; Gao, Yu-Tang; Shu, Xiao-Ou; Purdue, Mark P.

    2015-01-01

    Background Epidemiologic studies of occupational lead exposure have suggested increased risks of cancers of the stomach, lung, kidney, brain, and meninges; however, the totality of the evidence is inconsistent. Objective We investigated the relationship between occupational lead exposure and cancer incidence at the five abovementioned sites in two prospective cohorts in Shanghai, China. Methods Annual job/industry-specific estimates of lead fume and lead dust exposure, derived from a statistical model combining expert lead intensity ratings with inspection measurements, were applied to the lifetime work histories of participants from the Shanghai Women’s Health Study (SWHS; n = 73,363) and the Shanghai Men’s Health Study (SMHS; n = 61,379) to estimate cumulative exposure to lead fume and lead dust. These metrics were then combined into an overall occupational lead exposure variable. Cohort-specific relative hazard rate ratios (RRs) and 95% confidence intervals (CIs) comparing exposed and unexposed participants were estimated using Cox proportional hazards regression and combined by meta-analysis. Results The proportions of SWHS and SMHS participants with estimated occupational lead exposure were 8.9% and 6.9%, respectively. Lead exposure was positively associated with meningioma risk in women only (n = 38 unexposed and 9 exposed cases; RR = 2.4; 95% CI: 1.1, 5.0), particularly with above-median cumulative exposure (RR = 3.1; 95% CI: 1.3, 7.4). However, all 12 meningioma cases among men were classified as unexposed to lead. We also observed non-significant associations with lead exposure for cancers of the kidney (n = 157 unexposed and 17 ever exposed cases; RR = 1.4; 95% CI: 0.9, 2.3) and brain (n = 67 unexposed and 10 ever exposed cases; RR = 1.8; 95% CI: 0.7, 4.8) overall. Conclusions Our findings, though limited by small numbers of cases, suggest that lead is associated with the risk of several cancers in women and men. Citation Liao LM, Friesen MC, Xiang YB

  10. Effect of lead exposure on patterns of food intake in weanling rats.

    PubMed

    Minnema, D J; Hammond, P B

    1994-01-01

    The reduction in growth resulting from lead (PB) exposure in weanling rats is consistent with a lowering of the biological set-point for food intake. In this study the effects of lead on the patterns of food intake were examined. For 10 days (from ages 26 to 36 days), female rats were provided with drinking water containing 250 ppm lead as the acetate (n = 6) or equivalent acetate as sodium acetate (n = 6). A computerized system was used to monitor daily food intake at 5-min intervals over 10 successive 23-h periods (each period consisting of 12 h dark, 11 h light). Control rats consumed approximately 75% to 85% of their food intake during the dark phase. Exposure to lead resulted in decreased body weight, tail length, and cumulative food intake. Decreased food intake associated with lead during the first 6 days of exposure was due to a decrease in the size of each meal during the dark phase, which reflected a decrease in the duration of each meal. These results suggest that lead, at least initially, was affecting food-satiety signals to produce a premature termination of food intake during a meal. After 6 days, the lead-exposed rats appear to have adjusted their meal size and meal duration to approximately control values. However, this compensation appears to have occurred at the expense of the daily (nocturnal) number of meals, which decreased slightly (although not significantly) in lead-exposed animals. Thus, the total daily intake of food in lead-treated animals remained depressed relative to control animals.

  11. Environmental and biological monitoring for lead exposure in California workplaces.

    PubMed Central

    Rudolph, L; Sharp, D S; Samuels, S; Perkins, C; Rosenberg, J

    1990-01-01

    Patterns of environmental and biological monitoring for lead exposure were surveyed in lead-using industries in California. Employer self-reporting indicates a large proportion of potentially lead-exposed workers have never participated in a monitoring program. Only 2.6 percent of facilities have done environmental monitoring for lead, and only 1.4 percent have routine biological monitoring programs. Monitoring practices vary by size of facility, with higher proportions in industries in which larger facilities predominate. Almost 80 percent of battery manufacturing employees work in job classifications which have been monitored, versus only 1 percent of radiator-repair workers. These findings suggest that laboratory-based surveillance for occupational lead poisoning may seriously underestimate the true number of lead poisoned workers and raise serious questions regarding compliance with key elements of the OSHA Lead Standard. PMID:2368850

  12. Neonatal lead exposure impairs development of rodent barrel field cortex

    PubMed Central

    Wilson, Mary Ann; Johnston, Michael V.; Goldstein, Gary W.; Blue, Mary E.

    2000-01-01

    Childhood exposure to low-level lead can permanently reduce intelligence, but the neurobiologic mechanism for this effect is unknown. We examined the impact of lead exposure on the development of cortical columns, using the rodent barrel field as a model. In all areas of mammalian neocortex, cortical columns constitute a fundamental structural unit subserving information processing. Barrel field cortex contains columnar processing units with distinct clusters of layer IV neurons that receive sensory input from individual whiskers. In this study, rat pups were exposed to 0, 0.2, 1, 1.5, or 2 g/liter lead acetate in their dam's drinking water from birth through postnatal day 10. This treatment, which coincides with the development of segregated columns in the barrel field, produced blood lead concentrations from 1 to 31 μg/dl. On postnatal day 10, the area of the barrel field and of individual barrels was measured. A dose-related reduction in barrel field area was observed (Pearson correlation = −0.740; P < 0.001); mean barrel field area in the highest exposure group was decreased 12% versus controls. Individual barrels in the physiologically more active caudoventral group were affected preferentially. Total cortical area measured in the same sections was not altered significantly by lead exposure. These data support the hypothesis that lead exposure may impair the development of columnar processing units in immature neocortex. We demonstrate that low levels of blood lead, in the range seen in many impoverished inner-city children, cause structural alterations in a neocortical somatosensory map. PMID:10805810

  13. An optical interferometric technique for assessing ozone induced damage and recovery under cumulative exposures for a Japanese rice cultivar.

    PubMed

    Thilakarathne, Bodhipaksha Lalith Sanjaya; Rajagopalan, Uma Maheswari; Kadono, Hirofumi; Yonekura, Tetsushi

    2014-01-01

    Exposure to ozone (O3) causes reduction both in the growth and yield of rice (Oriza sativa L.). Commonly used Chlorophyll fluorescent measurements are not sensitive enough for short term exposure of O3 aiming an immediate assessments. Such a conventional method typically needs exposure over a few days to detect the influence. As an alternative method, we proposed a novel non-invasive, robust, real-time, optical Statistical Interferometric Technique (SIT) to measure growth at an accuracy of 0.1 nm with a commonly consumed Japanese rice cultivar, Koshihikari. In the present study, we have conducted a repetitive O3 exposure experiment for three days under three different concentrations of 0 nl l(-1) (control), 120 nl l(-1), and 240 nl l(-1), to investigate the damage and recovery strengths. As a measure to assess the effect and recovery from three consecutive day exposures of O3, we measured the elongation rate (nm mm(-1) sec(-1)) every 5.5 sec for 7 hours, and it revealed nanometric elongation rate fluctuations or Nanometric Intrinsic Fluctuations (NIF). Comparing the standard deviation (SD) of normalized nanometric intrinsic fluctuations (NNIF), which was normalized by that before the exposure, we found that drastic reductions under both 120 nl l(-1) and 240 nl l(-1) O3 concentrations. Reduction percentages were large under high O3 concentration of 240 nl l(-1) indicating the possibility of irreversible effect. However exposure to 120 nl l(-1) of O3 showed recovery on the 2(nd) and 3(rd) days. While SIT did reveal immediate effect based on an observation for a few hours, the visible foliar effect could be observed only after a week. Hence, the technique could provide a way for fast assessment of effect and recovery due to cumulative exposure of O3 and hence the tolerance as well as the vitality of plant.

  14. Neurotoxic Effects and Biomarkers of Lead Exposure: A Review

    PubMed Central

    Sanders, Talia; Liu, Yiming; Buchner, Virginia; Tchounwou, Paul B.

    2010-01-01

    Biological monitoring techniques are useful for risk assessment of toxic agents in the field of environmental health. Lead, a systemic toxicant affecting virtually every organ system, primarily affects the central nervous system, particularly the developing brain. Consequently, children are at a greater risk than adults of suffering from the neurotoxic effects of lead. The ability of lead to pass through the blood-brain barrier is due in large part to its ability to substitute for calcium ions. Within the brain, lead-induced damage in the prefrontal cerebral cortex, hippocampus, and cerebellum can lead to a variety of neurological disorders, such as brain damage, mental retardation, behavioral problems, nerve damage, and possibly Alzheimer’s disease, Parkinson’s disease, and schizophrenia. At the molecular level, lead interferes with the regulatory action of calcium on cell functions and disrupts many intracellular biological activities. Experimental studies have also shown that lead exposure may have genotoxic effects, especially in the brain, bone marrow, liver, and lung cells. This paper presents an overview of biomarkers of lead exposure and discusses the neurotoxic effects of lead with regard to children, adults, and experimental animals, updated to January 2009. PMID:19476290

  15. Influence of social factors on lead exposure and child development.

    PubMed Central

    Bornschein, R L

    1985-01-01

    A brief overview of current views of child development is provided, with particular attention given to the role the child's physical and social environment plays in influencing the developmental process. Examples from the recent literature are used to illustrate how these factors can influence lead exposure and most importantly how they might interact with lead to ameliorate or exacerbate possible lead effects. An example is provided which demonstrates that failure to control adequately and to adjust the data statistically to correct for the influence of these factors can lead one erroneously to attribute cognitive and behavioral changes to lead. Finally, data from the Cincinnati Prospective Lead Study are presented to illustrate the application of structural equation modeling as a means for unraveling the complex web of sociodemographic, environmental and behavioral influences on childhood lead exposure. The latter analysis indicates that for children less than 24 months of age, lead-containing dust in the home and on the children's hands are important determinates of their blood lead levels. This relationship is influenced by the amount of maternal involvement with their child and other indices of interaction between the child and primary caregiver. PMID:2417831

  16. Prenatal lead exposure enhances methamphetamine sensitization in rats.

    PubMed

    Clifford, P Shane; Hart, Nigel; Thompson, Jeff; Buckman, Sam; Wellman, Paul J; Bratton, Gerald R; Nation, Jack R

    2009-08-01

    Adult female rats were exposed to lead-free sodium acetate via gavage [0 mg (vehicle control)] or to 16 mg lead as lead acetate for 30 days prior to breeding. Following confirmation of breeding, the female animals continued to be exposed to their respective doses throughout gestation and lactation. When weaned, 16 control and 16 lead-exposed offspring were placed on regular water and food (lead-exposure was discontinued) until postnatal day (PND) 70. At this time, one-half of the control animals and one-half of the lead-treatment animals received intraperitoneal (i.p.) injections of the vehicle (saline) for 10 successive days and the remaining animals in each exposure conditions received daily injections of 1.0 mg/kg (+)-methamphetamine (METH) for 10 days (N=8/group). Locomotion in automated chambers was monitored daily for 45 min post-injection. Subsequently, during dose-effect testing, all animals received consecutive daily i.p. injections of 0, 1.0, 2.0, and then 4.0 mg/kg METH. The results of the experiment showed that both control and lead-exposed animals exhibited heightened locomotor activity (i.e. behavioral sensitization) to the repeated administration of 1.0 mg/kg METH. More importantly, animals developmentally (perinatally) exposed to lead showed more rapid sensitization than did their control counterparts. These data indicate that early lead exposure increases sensitivity to the locomotor-stimulating effects of METH. In contrast, identically exposed lead animals exhibit diminished METH dose-effect responding when tested in an intravenous (i.v.) self-administration paradigm [Rocha A., Valles R., Bratton G.R., Nation J.R. Developmental lead exposure alters methamphetamine self-administration in the male rat: acquisition and reinstatement. Drug Alcohol Depend 2008a;95:23-29, Rocha A., Valles R., Hart N., Bratton G.R., Nation J.R. Developmental lead exposure attenuates methamphetamine dose-effect self-administration performance and progressive ratio

  17. Lead exposure and behavioral changes: comparisons of four occupational groups with different levels of lead absorption.

    PubMed

    Valciukas, J A; Lilis, R; Singer, R; Fischbein, A; Anderson, H A; Glickman, L

    1980-01-01

    The association between lead absorption and objective psychological performance tests in five groups with different levels of lead absorption was studied in the following groups: (1) a control, non-lead-exposed group; (2) cable splicers, (3) cable manufactures, and (4) secondary lead smelter workers. The following performance tests were used: Block Design, Digit Symbol, and Embedded Figures. Age-corrected performance test scores and the average of three test scores (INDEX) were used throughout. A significant association between performance tests scores and increased lead absorption was found. Zinc protoporphyrin level was a more "powerful" (in the statistical sense) indicator of lead-induced CNS effects than blood lead levels. This study provides additional evidence that neurotoxic effects associated with occupational exposure to lead can be demonstrated by means of performance tests. It has been known and widely accepted that increased lead absorption is associated with "non-specific" subjective symptoms: tiredness, sleep disturbance, irritability, etc. Psychometric techniques (including an appropriate statistical analysis strategy) are highly sensitive for the early detection of CNS neurotoxicity, such as metal toxicity. Moreover, even in lead-exposed but asymptomatic individuals, a significant correlation (negative) between test scores and levels of lead absorption could be detected. It is concluded that workers exposed to lead at levels considered "safe" might be at risk of developing brain dysfunction with long term exposure.

  18. Lead

    MedlinePlus

    ... EPA United States Environmental Protection Agency Search Search Lead Contact Us Share Lead Poisoning is Preventable If your home was built ... to protect people from harmful lead exposures. Less Lead in Drinking Water = Better Health Learn about the ...

  19. Hypertension`s lead connection: Does low-level exposure to lead cause high blood pressure?

    SciTech Connect

    Fackelmann, K.

    1996-06-15

    {open_quotes}Paying for the sins of the past.{close_quotes} is how researcher Howard Hu describes a proposed disease process in which lead stored for decades in the skeleton puts people at risk of high blood pressure. Previous research has linked this silvery white, poisonous metal to a host of ill effects in children, including learning disabilities, behavior problems, and brain damage. Now, Hu`s study indicates that past exposure may be causing today`s high blood pressure. If he`s right, the public health impact would be significant. {open_quotes}Tens of millions of Americans have been exposed over the years to lead,{close_quotes} says Philip J. Landrigan of Mount Sinai Medical Center in New York. {open_quotes}Adults today grew up at a time when we were still putting several hundred thousand tons of lead into gasoline each year.{close_quotes} Indeed, the men who developed high blood pressure during the recent study had in their bones lead concentrations, or lead burdens, that came from decades of everyday exposure. Such exposures resulted principally from breathing in fumes from leaded gasoline, drinking tap water from lead pipes or pipes soldered with lead, and inhaling or ingesting lead-laced paint dust or chips. This article goes on to discuss other studies and questions which still need to be answered.

  20. Probabilistic acute risk assessment of cumulative exposure to organophosphorus and carbamate pesticides from dietary vegetables and fruits in Shanghai populations.

    PubMed

    Li, Fan; Yuan, Yaqun; Meng, Pai; Wu, Min; Li, Shuguang; Chen, Bo

    2017-02-03

    Organophosphorus pesticides (OPs) and carbamate pesticides (CPs) are among the most widely used pesticides in China, playing a major role in protecting agricultural commodities. In this study, we determined the cumulative acute exposure to OPs and CPs of Shanghai residents from vegetables and fruits (VFs). The food consumption data were obtained from the Shanghai Food Consumption Survey (SHFCS) of 2012-14 including a total of 1973 participants aged 2-90 years. The pesticide residue data were obtained from the Shanghai monitoring programme during 2008-11 with 34 organophosphates and 11 carbamates analysed in a total of 5335 samples of VFs. A probabilistic approach was performed as recommended by the EFSA, using the optimistic model with non-detects set as zero and with processing factors (PFs) being used and the pessimistic model with non-detects replaced by limit of detection (LOD) and without PFs. We used the relative potency factor (RPF) method to normalise the various pesticides to the index compound (IC) of methamidophos and chlorpyrifos separately. Only in the pessimistic model using methamidophos as the IC was there was small risk of exposure exceeding the ARfD (3 µg kg(-)(1) bw day(-)(1)) in the populations of preschool children (0.029%), school-age children (0.022%) and adults (0.002%). There were no risk of exposure exceeding the ARfD of methamidophos in the optimistic model and of chlorpyrifos (100 µg kg(-)(1) bw day(-)(1)) in both optimistic and pessimistic models in all three populations. Considering the Chinese habits of overwhelmingly eating processed food (vegetables being cooked, and fruits being washed or peeled), we conclude that little acute risk was found for the exposure to VF-sourced OPs and CPs in Shanghai.

  1. Developmental lead exposure has mixed effects on butterfly cognitive processes.

    PubMed

    Philips, Kinsey H; Kobiela, Megan E; Snell-Rood, Emilie C

    2017-01-01

    While the effects of lead pollution have been well studied in vertebrates, it is unclear to what extent lead may negatively affect insect cognition. Lead pollution in soils can elevate lead in plant tissues, suggesting it could negatively affect neural development of insect herbivores. We used the cabbage white butterfly (Pieris rapae) as a model system to study the effect of lead pollution on insect cognitive processes, which play an important role in how insects locate and handle resources. Cabbage white butterfly larvae were reared on a 4-ppm lead diet, a concentration representative of vegetation in polluted sites; we measured eye size and performance on a foraging assay in adults. Relative to controls, lead-reared butterflies did not differ in time or ability to search for a food reward associated with a less preferred color. Indeed, lead-treated butterflies were more likely to participate in the behavioral assay itself. Lead exposure did not negatively affect survival or body size, and it actually sped up development time. The effects of lead on relative eye size varied with sex: lead tended to reduce eye size in males, but increase eye size in females. These results suggest that low levels of lead pollution may have mixed effects on butterfly vision, but only minimal impacts on performance in foraging tasks, although follow-up work is needed to test whether this result is specific to cabbage whites, which are often associated with disturbed areas.

  2. Cardiotoxicity and hypertension in rats after oral lead exposure.

    PubMed

    Lal, B; Murthy, R C; Anand, M; Chandra, S V; Kumar, R; Tripathi, O; Srimal, R C

    1991-01-01

    The rats were exposed to lead (0.25, 0.5 and 1.0 per cent lead acetate through drinking water) for 90 days to study its effect on some physiological and morphological parameters of the cardiovascular system. Blood lead levels increased in a dose dependent manner but heart tissue showed rise at only two higher doses in exposed animals. The two higher doses of lead resulted in an increased arterial blood pressure and calcium influx in atrial trabeculae and papillary muscles. No marked pathological or histochemical changes were observed in heart tissue excepting congestion and slightly reduced activity of succinic dehydrogenase in the highest dosed group. It was concluded that lead exposure through drinking water may produce increased arterial blood pressure and minor changes in the myocardium. Whether these changes are mediated through the effect of lead on the calcium transport needs further investigation.

  3. Public health. Childhood lead exposure in Wisconsin in 1990

    SciTech Connect

    Schirmer, J.; Anderson, H.; Peterson, D.E. )

    1991-01-01

    It will take the cooperation of many people to address the issue of lead poisoning. The recent death has dramatized the problem of high dose exposures. But a larger challenge is posed by the fact that most preschool children in Wisconsin are not screened for lead and as a result many asymptomatic children without signs of pica behavior will experience subtle neurological damage as a result of low to moderate elevations of lead in blood. Because many of these cases occur in children without recognized pica behavior, doctors need to expand screening, especially during well child visits, to identify children with elevated blood lead levels. Additionally, the public health community and property owners need to evaluate and control sources of lead. Major efforts are needed to address the lead hazards which now impair hundreds of Wisconsin children each year.

  4. CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS.

    EPA Science Inventory

    CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS. ME Gilbert1, ME Kelly2, S. Salant3, T Shafer1, J Goodman3 1Neurotoxicology Div, US EPA, RTP, NC, 27711, 2Children's Hospital, Philadelphia, PA, 19104, 3Helen Hayes Hospital, Haverstraw, NY, 10993.
    ...

  5. CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS.

    EPA Science Inventory

    CHRONIC DEVELOPMENTAL LEAD EXPOSURE REDUCES NEUROGENESIS IN ADULT HIPPOCAMPUS. ME Gilbert1, ME Kelly2, S. Salant3, T Shafer1, J Goodman3 1Neurotoxicology Div, US EPA, RTP, NC, 27711, 2Children's Hospital, Philadelphia, PA, 19104, 3Helen Hayes Hospital, Haverstraw, NY, 10993.
    ...

  6. Lead exposure and educational proficiency: moderate lead exposure and educational proficiency on end-of-grade examinations.

    PubMed

    Amato, Michael S; Moore, Colleen F; Magzamen, Sheryl; Imm, Pamela; Havlena, Jeffrey A; Anderson, Henry A; Kanarek, Marty S

    2012-10-01

    To investigate and quantify the impact of moderate lead exposure on students' ability to score at the "proficient" level on end-of-grade standardized tests. We compared the scores of 3757 fourth grade students from Milwaukee, Wisconsin, on the Wisconsin Knowledge and Concepts Exam (WKCE). The sample consisted of children with a blood lead test before age 3 years that was either unquantifiable at the time of testing (<5 μg/dL) or in the range of moderate exposure (10-19 μg/dL). After controlling for gender, poverty, English language learner status, race/ethnicity, school disciplinary actions, and attendance percentage, results showed a significant negative effect of moderate lead exposure on academic achievement for all 5 subtests of the WKCE. Test score deficits owing to lead exposure were equal to 22% of the interval between student categorization at the "proficient" or "basic" levels in Reading, and 42% of the interval in Mathematics. Children exposed to amounts of lead before age 3 years that are insufficient to trigger intervention under current policies in many states are nonetheless at a considerable educational disadvantage compared with their unexposed peers 7 to 8 years later. Exposed students are at greater risk of scoring below the proficient level, an outcome with serious negative consequences for both the student and the school. Copyright © 2012 Elsevier Inc. All rights reserved.

  7. Leaded crystal as a source of dietary lead: An exposure assessment

    SciTech Connect

    Shorten, C.V.; Glowacki, M.L.

    1995-12-31

    Lead is a potent systemic toxic with many environmental sources. It can enter the body through a number of pathways, the most significant is ingestion. While many investigators of lead ingestion have focused on paint and dust sources, the authors examined food contaminated with lead from crystal ware. The rates and amounts of lead leached into vinegar stored in leaded crystal cruets were measured over the course of a 42-day laboratory study. Replicate lead oxide (PbO, 24%) crystal cruets (N = 13) were filled with vinegar, and sample aliquots were periodically removed for analysis. Lead leaching rates were determined by fitting a two-stage, non-linear model to the data, and observed rate coefficients were 0.066 hr{sup {minus}1} and 0.0019{sup {minus}1} for the first and second stages of leaching, respectively (R{sup 2} = 0.9680). Average lead concentrations in the stored vinegar range from 118 {micro}g/L at 8 parameters (ingestion rate, exposure frequency and duration, body weight, and averaging time) was generated to characterize the realm of potential intake estimates. Lead concentrations were input using the fitted model. Results indicated that a worst case lead intake estimate from this source could be as high as 420 {micro}g/kg/yr for a child. Crystal ware can be considered to be a potentially significant dietary source of lead, and risk characterizations cannot ignore this potential avenue when combining risks across all exposure pathways.

  8. Substance Use and Cumulative Exposure to American Society: Findings From Both Sides of the US–Mexico Border Region

    PubMed Central

    Cherpitel, Cheryl J.; Orozco, Ricardo; Zemore, Sarah E.; Wallisch, Lynn; Medina-Mora, Maria-Elena; Breslau, Joshua

    2016-01-01

    Objectives. We investigated whether Mexican immigration to the United States exerts transnational effects on substance use in Mexico and the United States. Methods. We performed a cross-sectional survey of 2336 Mexican Americans and 2460 Mexicans in 3 Texas border metropolitan areas and their sister cities in Mexico (the US–Mexico Study on Alcohol and Related Conditions, 2011–2013). We collected prevalence and risk factors for alcohol and drug use; Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, alcohol-use disorders; and 2 symptoms (hazardous use and quit or control) of drug use disorder across a continuum of migration experiences in the Mexican and Mexican American populations. Results. Compared with Mexicans with no migrant experience, the adjusted odds ratios for this continuum of migration experiences ranged from 1.10 to 8.85 for 12-month drug use, 1.09 to 5.07 for 12-month alcohol use disorder, and 1.13 to 9.95 for 12-month drug-use disorder. Odds ratios increased with longer exposure to US society. These findings are consistent with those of 3 previous studies. Conclusions. People of Mexican origin have increased prevalence of substance use and disorders with cumulative exposure to US society. PMID:26562124

  9. Substance Use and Cumulative Exposure to American Society: Findings From Both Sides of the US-Mexico Border Region.

    PubMed

    Borges, Guilherme; Cherpitel, Cheryl J; Orozco, Ricardo; Zemore, Sarah E; Wallisch, Lynn; Medina-Mora, Maria-Elena; Breslau, Joshua

    2016-01-01

    We investigated whether Mexican immigration to the United States exerts transnational effects on substance use in Mexico and the United States. We performed a cross-sectional survey of 2336 Mexican Americans and 2460 Mexicans in 3 Texas border metropolitan areas and their sister cities in Mexico (the US-Mexico Study on Alcohol and Related Conditions, 2011-2013). We collected prevalence and risk factors for alcohol and drug use; Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, alcohol-use disorders; and 2 symptoms (hazardous use and quit or control) of drug use disorder across a continuum of migration experiences in the Mexican and Mexican American populations. Compared with Mexicans with no migrant experience, the adjusted odds ratios for this continuum of migration experiences ranged from 1.10 to 8.85 for 12-month drug use, 1.09 to 5.07 for 12-month alcohol use disorder, and 1.13 to 9.95 for 12-month drug-use disorder. Odds ratios increased with longer exposure to US society. These findings are consistent with those of 3 previous studies. People of Mexican origin have increased prevalence of substance use and disorders with cumulative exposure to US society.

  10. Low level exposures to lead and neurobehavioral development: the Sydney lead study

    SciTech Connect

    Cooney, G.H.; Bell, A.; McBride, W.; Carter, C.

    1988-01-01

    The Sydney lead study is a prospective five year study investigating the relationship between low level lead exposures and neurobehavioral development during the first five years of life. From an initial cohort of 318 children, 207 remained at the end of the fourth year. Average blood lead levels at 42 and 48 months were 10.6 ug/dL and 10.1 ug/dL respectively, with only a minority of the observations exceeding 15 ug/dL. The series of regression analyses reported in this paper support earlier findings from the study, that exposures to lead which give rise to the range of blood lead levels found in this cohort of children are not associated with cognitive or motor deficits in the preschool years.

  11. [Association between low blood lead exposure and nervous system symptoms].

    PubMed

    Dou, Qianru; Wang, Yan; Cai, Chang; Li, Jimeng; Tan, Hongzhuan

    2015-05-01

    To explore the association between low blood lead exposure and nervous system symptoms among the workers exposed to oil paint. Through cluster sampling, workers with occupational oil paint exposure in 2 factories were selected to conduct a questionnaire survey, biochemical detection and health examination. χ2 test and unconditional logistic regression analysis were performed for the determinants analysis. A total of 525 oil paint workers completed the survey, in whom, 55 (10.5%) were blood lead positive, the mean of blood lead concentration was (0.0884±0.0539) mg/L, 278 (52.95%) had nervous system like symptoms and 69 (13.14%) had peripheral neuropathy symptoms. Multinomial logistic regression analysis showed that working age (OR=1.827), drinking (OR=1.607), health status (OR=3.862), blood lead (OR=1.983) were risk factors for nervous system like symptoms. Working age (OR=2.282), and drinking (OR=2.704) were risk factors for peripheral neuropathy. Low blood lead exposure might be associated with nervous system like symptoms.

  12. An Integrated Modeling Framework Forecasting Ecosystem Exposure-- A Systems Approach to the Cumulative Impacts of Multiple Stressors

    NASA Astrophysics Data System (ADS)

    Johnston, J. M.

    2013-12-01

    Freshwater habitats provide fishable, swimmable and drinkable resources and are a nexus of geophysical and biological processes. These processes in turn influence the persistence and sustainability of populations, communities and ecosystems. Climate change and landuse change encompass numerous stressors of potential exposure, including the introduction of toxic contaminants, invasive species, and disease in addition to physical drivers such as temperature and hydrologic regime. A systems approach that includes the scientific and technologic basis of assessing the health of ecosystems is needed to effectively protect human health and the environment. The Integrated Environmental Modeling Framework 'iemWatersheds' has been developed as a consistent and coherent means of forecasting the cumulative impact of co-occurring stressors. The Framework consists of three facilitating technologies: Data for Environmental Modeling (D4EM) that automates the collection and standardization of input data; the Framework for Risk Assessment of Multimedia Environmental Systems (FRAMES) that manages the flow of information between linked models; and the Supercomputer for Model Uncertainty and Sensitivity Evaluation (SuperMUSE) that provides post-processing and analysis of model outputs, including uncertainty and sensitivity analysis. Five models are linked within the Framework to provide multimedia simulation capabilities for hydrology and water quality processes: the Soil Water Assessment Tool (SWAT) predicts surface water and sediment runoff and associated contaminants; the Watershed Mercury Model (WMM) predicts mercury runoff and loading to streams; the Water quality Analysis and Simulation Program (WASP) predicts water quality within the stream channel; the Habitat Suitability Index (HSI) model scores physicochemical habitat quality for individual fish species; and the Bioaccumulation and Aquatic System Simulator (BASS) predicts fish growth, population dynamics and bioaccumulation

  13. Behavioral effects of low level neonatal lead exposure.

    PubMed

    Hastings, L; Cooper, G P; Bornschein, R L; Michaelson, I A

    1977-07-01

    Rats exposed to lead via maternal milk were tested at various stages of development on a number of behavioral tasks. Beginning at paturition, the dams were given either tap water, 0.02%, or 0.10% lead acetate in the drinking water. Pups from all three groups were weaned to normal chow and tap water at 21 days of age. The mean lead concentration of the dam's blood and of neonatal (20 days of age) brain and blood were all below 50 microgram/100 ml. No significant differences were found between the high lead-exposed group and controls in general as measured by wheel running over a 21 day period beginning at 30 days of age. However, there was a significant difference in wheel running behavior during the first three hr of testing. Both lead-exposed groups were found to display significantly less aggressive behavior as measured by the shock-elicited aggression test. Low level lead exposure had no discernable effect on the acquisition and subsequent reversal of a successive brightness discrimination task. Lead exposure under these conditions appears to affect some aspects of emotional behavior, while having little effect on general activity or cognitive function.

  14. Environmental and Occupational Lead Exposure Among Children in Cairo, Egypt

    PubMed Central

    Moawad, Eman Mohamed Ibraheim; Badawy, Nashwa Mostafa; Manawill, Marie

    2016-01-01

    Abstract The aim of this study was to assess childhood lead exposure in a representative sample of Cairo, and to investigate the possible risk factors and sources of exposure. This cross-sectional study was conducted from November 2014 through April 2015. The target population was children aged 6 to 18 years, recruited into 4 groups, garbage city, moderate-living standard area, urban and suburban schools, and workshops in the city of Cairo. Blood lead levels (BLLs) and hemoglobin (Hb) concentrations were measured. Also, potential local environmental sources were assessed for hazardous lead contamination. Analysis on 400 participants has been carried out. A total of 113 children had BLLs in the range 10 to 20 μg/dL. Smoking fathers, housing conditions, playing outdoors, and exposure to lead in residential areas were significantly correlated with high BLLs. The mean values of hemoglobin were inversely correlated with BLLs. Children involved in pottery workshops had the highest BLLs and the lowest Hb values with a mean of (43.3 μg/dL and 8.6 g/dL, respectively). The mean value of environmental lead in workshop areas exceeded the recommended levels. Also, those values measured in dust and paint samples of garbage city were significantly high. Moreover, the mean lead levels in the soil samples were significantly higher in urban schools (P = 0.03) than the suburban ones. Childhood lead poisoning accounts for a substantial burden in Egypt, which could be preventable. Development of national prevention programs including universal screening program should be designed to reduce incidence of lead toxicity among children. PMID:26945415

  15. Individual and cumulative impacts of fire emissions and tobacco consumption on wildland firefighters' total exposure to polycyclic aromatic hydrocarbons.

    PubMed

    Oliveira, Marta; Slezakova, Klara; Magalhães, Carlos Pires; Fernandes, Adília; Teixeira, João Paulo; Delerue-Matos, Cristina; do Carmo Pereira, Maria; Morais, Simone

    2017-07-15

    There is limited information about wildland firefighters' exposure to polycyclic aromatic hydrocarbons (PAHs), being scarce studies that included the impact of tobacco consumption. Thus, this work evaluated the individual and cumulative impacts of firefighting activities and smoking on wildland firefighters' total exposure to PAHs. Six urinary PAH metabolites (1-hydroxynaphthalene (1OHNaph), 1-hydroxyacenaphthene (1OHAce), 2-hydroxyfluorene (2OHFlu), 1-hydroxyphenanthrene (1OHPhen), 1-hydroxypyrene (1OHPy), and 3-hydroxybenzo[a]pyrene (3OHB[a]P)) were quantified by high-performance liquid chromatography with fluorescence detection. Firefighters from three fire stations were characterized and organized in three groups: non-smoking and non-exposed to fire emissions (NSNExp), smoking non-exposed (SNExp), and smoking exposed (SExp) individuals. 1OHNaph+1OHAce were the most predominant OH-PAHs (66-91% ∑OH-PAHs), followed by 2OHFlu (2.8-28%), 1OHPhen (1.3-7%), and 1OHPy (1.4-6%). 3OHB[a]P, the carcinogenicity PAH biomarker, was not detected. Regular consumption of tobacco increased 76-412% ∑OH-PAHs. Fire combat activities promoted significant increments of 158-551% ∑OH-PAHs. 2OHFlu was the most affected compound by firefighting activities (111-1068%), while 1OHNaph+1OHAce presented the more pronounced increments due to tobacco consumption (22-339%); 1OHPhen (76-176%) and 1OHPy (20-220%) were the least influenced ones. OH-PAH levels of SExp firefighters were significantly higher than in other groups, suggesting that these subjects may be more vulnerable to develop and/or aggravate diseases related with PAHs exposure. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Occupational exposure to lead: effects on renal function

    SciTech Connect

    Hong, C.D.; Hanenson, I.B.; Lerner, S.; Hammond, P.B.; Pesce, A.J.; Pollak, V.E.

    1980-10-01

    Although nephrotoxicity is common following exposure to lead, the dose-response relationship in adults with occupational exposure is not well understood because information is lacking on early nephrotoxic effects. By the time serum urea nitrogen and creatinine levels are elevated, renal damage may be advanced and not fully reversible. Detailed investigations of renal glomerular and tubular function were performed in six adults with occupational exposure to lead. In all patients, the serum creatinine and urea nitrogen concentrations were within the normal range. GFR was decreased in all but two. Glucose reabsorptive capacity (TmG) was decreased in all, and this decrease was disproportionately greater than expected from the reduced GFR in all but one. Normal values for renal plasma flow (RFP) were observed in four of the six, and for rho-aminohippurate (PAH) secretory capacity (TmPAh) in all but one. Bicarbonate reabsorptive capacity (TmHCO3) and urinary excretion of beta2-microglobulin were normal in all. Routine clinical laboratory tests are insensitive for the detection of early renal effects of heavy metal exposure. Measurements of renal tubular reabsorptive capacity for glucose appears to be a sensitive method for the early detection of renal effect of lead.

  17. Lead Exposure during Early Human Development and DNA Methylation of Imprinted Gene Regulatory Elements in Adulthood

    SciTech Connect

    Li, Yue; Xie, Changchun; Murphy, Susan K.; Skaar, David; Nye, Monica; Vidal, Adriana C.; Cecil, Kim M.; Dietrich, Kim N.; Puga, Alvaro; Jirtle, Randy L.; Hoyo, Cathrine

    2015-06-26

    Here, lead exposure during early development causes neurodevelopmental disorders by unknown mechanisms. Epidemiologic studies have focused recently on determining associations between lead exposure and global DNA methylation; however, such approaches preclude the identification of loci that may alter human disease risk. The objective of this study was to determine whether maternal, postnatal, and early childhood lead exposure can alter the differentially methylated regions (DMRs) that control the monoallelic expression of imprinted genes involved in metabolism, growth, and development. Questionnaire data and serial blood lead levels were obtained from 105 participants (64 females, 41 males) of the Cincinnati Lead Study from birth to 78 months. When participants were adults, we used Sequenom EpiTYPER assays to test peripheral blood DNA to quantify CpG methylation in peripheral blood leukocytes at DMRs of 22 human imprinted genes. Statistical analyses were conducted using linear regression. Mean blood lead concentration from birth to 78 months was associated with a significant decrease in PEG3 DMR methylation (β = –0.0014; 95% CI: –0.0023, –0.0005, p = 0.002), stronger in males (β = –0.0024; 95% CI: –0.0038, –0.0009, p = 0.003) than in females (β = –0.0009; 95% CI: –0.0020, 0.0003, p = 0.1). Elevated mean childhood blood lead concentration was also associated with a significant decrease in IGF2/H19 (β = –0.0013; 95% CI: –0.0023, –0.0003, p = 0.01) DMR methylation, but primarily in females, (β = –0.0017; 95% CI: –0.0029, –0.0006, p = 0.005) rather than in males, (β = –0.0004; 95% CI: –0.0023, 0.0015, p = 0.7). Elevated blood lead concentration during the neonatal period was associated with higher PLAGL1/HYMAI DMR methylation regardless of sex (β = 0.0075; 95% CI: 0.0018, 0.0132, p = 0.01). The magnitude of associations between cumulative lead exposure and CpG methylation remained unaltered from 30 to 78 months. Our findings

  18. Lead Exposure during Early Human Development and DNA Methylation of Imprinted Gene Regulatory Elements in Adulthood

    DOE PAGES

    Li, Yue; Xie, Changchun; Murphy, Susan K.; ...

    2015-06-26

    Here, lead exposure during early development causes neurodevelopmental disorders by unknown mechanisms. Epidemiologic studies have focused recently on determining associations between lead exposure and global DNA methylation; however, such approaches preclude the identification of loci that may alter human disease risk. The objective of this study was to determine whether maternal, postnatal, and early childhood lead exposure can alter the differentially methylated regions (DMRs) that control the monoallelic expression of imprinted genes involved in metabolism, growth, and development. Questionnaire data and serial blood lead levels were obtained from 105 participants (64 females, 41 males) of the Cincinnati Lead Study frommore » birth to 78 months. When participants were adults, we used Sequenom EpiTYPER assays to test peripheral blood DNA to quantify CpG methylation in peripheral blood leukocytes at DMRs of 22 human imprinted genes. Statistical analyses were conducted using linear regression. Mean blood lead concentration from birth to 78 months was associated with a significant decrease in PEG3 DMR methylation (β = –0.0014; 95% CI: –0.0023, –0.0005, p = 0.002), stronger in males (β = –0.0024; 95% CI: –0.0038, –0.0009, p = 0.003) than in females (β = –0.0009; 95% CI: –0.0020, 0.0003, p = 0.1). Elevated mean childhood blood lead concentration was also associated with a significant decrease in IGF2/H19 (β = –0.0013; 95% CI: –0.0023, –0.0003, p = 0.01) DMR methylation, but primarily in females, (β = –0.0017; 95% CI: –0.0029, –0.0006, p = 0.005) rather than in males, (β = –0.0004; 95% CI: –0.0023, 0.0015, p = 0.7). Elevated blood lead concentration during the neonatal period was associated with higher PLAGL1/HYMAI DMR methylation regardless of sex (β = 0.0075; 95% CI: 0.0018, 0.0132, p = 0.01). The magnitude of associations between cumulative lead exposure and CpG methylation remained unaltered from 30 to 78 months. Our

  19. [Lead exposure in pregnant women and newborns: a screening update].

    PubMed

    Yazbeck, C; Cheymol, J; Dandres, A-M; Barbéry-Courcoux, A-L

    2007-01-01

    Human lead exposure has many sources. Relative importance of these sources varies widely according to geographic regions and human lifestyle. The impact of lead exposure on health has been well studied and public health interventions have been conducted. The aim of this study was to evaluate current prevalence of lead burden in neonates, and seek for sources of maternal and fetal intoxication. A prospective multicentre study was conducted by the "Réseau périnatal 92" on a population of pregnant women attending 3 maternal wards in the north of 'Hauts-de-Seine' department in France. Between December 2003 and May 2004, a total of 1021 pregnant women were included. All patients signed an informed consent before participating in the study. Cord blood samples were collected at delivery for lead measurements. The mean cord blood lead concentration was 23.2 microg/l. Eighteen neonates over 1021 (1.8%) had lead levels above 100 microg/l. An environmental query was conducted by the social and public health office of the department (DDASS), and data were collected regarding the state of the housing and the lifestyle of the concerned family. Main sources of lead intoxication were 'tagine' food plates in 83.3% of cases, 'khôl' powder (used as eyeliner) in 88.9% of cases and substandard housings in 22.2% of cases. A specialized paediatric follow-up for the 18 neonates was performed. With the exception of substandard housing (old lead painting), other sources of lead intoxication were discovered: 'tagine' plates and 'khôl' powder. Almost all of these products came from Morocco. A public health intervention would be able to inform the population about these yet unknown sources of lead intoxication.

  20. Influence of the degree of exposure to lead on relations between alcohol consumption and the biological indices of lead exposure: epidemiological study in a lead acid battery factory.

    PubMed Central

    Cezard, C; Demarquilly, C; Boniface, M; Haguenoer, J M

    1992-01-01

    Alcohol has been shown to interact with lead to influence haem biosynthesis. The aim of this study was to define the dependence of this interaction on the degree of exposure to lead. Exposure to alcohol was estimated by measurement of alcohol concentrations in a sample of urine collected during the morning (AlcUM) (0.82 (SD 4.36) mmol/l) and in a sample collected during the afternoon (AlcUA) (1.15 (SD 3.49) mmol/l). The biological monitoring of exposure to lead included measurements of blood lead (Pb-B) (1.82 (SD 0.72) mumol/l), urinary delta-aminolaevulinic acid (ALAU) (35.33 (SD 28.00) mumol/l; d = 1.015), and erythrocyte zinc-protoporphyrin (ZPP) (112.90 (SD 83.71) nmol/mmol Hb) concentrations. The study of the influence of the degree of occupational exposure to lead on relations between alcohol consumption and effects of the exposure to lead led to the consideration of two different groups--namely, mildly and strongly exposed subjects. In the first group, individual biological susceptibility seemed to play a preponderant part. In the second, the pool of lead present in the body seemed to be sufficiently important to mask the effects of individual susceptibility. PMID:1390270

  1. Repeated exposure to high-frequency spanking and child externalizing behavior across the first decade: A moderating role for cumulative risk

    PubMed Central

    MacKenzie, Michael J.; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

    2016-01-01

    This study used the Fragile Families and Child Well-being study to examine the effects of repeated exposure to harsh parenting on child externalizing behavior across the first decade of life, and a moderating role for cumulative ecological risk. Maternal report of harsh parenting, defined as high frequency spanking, was assessed at age 1, 3, 5, and 9, along with child externalizing at age 9 (N=2768). Controlling for gender, race, maternal nativity, and city of residence, we found a cumulative risk index to significantly moderate the effects of repeated harsh parenting on child behavior, with the effects of repeated high-frequency spanking being amplified for those experiencing greater levels of cumulative risk. Harsh parenting, in the form of high frequency spanking, remains a too common experience for children, and results demonstrate that the effects of repeated exposure to harsh parenting across the first decade are amplified for those children already facing the most burden. PMID:25465318

  2. Repeated exposure to high-frequency spanking and child externalizing behavior across the first decade: a moderating role for cumulative risk.

    PubMed

    MacKenzie, Michael J; Nicklas, Eric; Brooks-Gunn, Jeanne; Waldfogel, Jane

    2014-12-01

    This study used the Fragile Families and Child Well-Being Study to examine the effects of repeated exposure to harsh parenting on child externalizing behavior across the first decade of life, and a moderating role for cumulative ecological risk. Maternal report of harsh parenting, defined as high frequency spanking, was assessed at age 1, 3, 5, and 9, along with child externalizing at age 9 (N=2,768). Controlling for gender, race, maternal nativity, and city of residence, we found a cumulative risk index to significantly moderate the effects of repeated harsh parenting on child behavior, with the effects of repeated high-frequency spanking being amplified for those experiencing greater levels of cumulative risk. Harsh parenting, in the form of high frequency spanking, remains a too common experience for children, and results demonstrate that the effects of repeated exposure to harsh parenting across the first decade are amplified for those children already facing the most burden.

  3. Primary Prevention of Lead Exposure: The Philadelphia Lead Safe Homes Study

    PubMed Central

    Campbell, Carla; Tran, Mary; Gracely, Edward; Starkey, Naomi; Kersten, Hans; Palermo, Peter; Rothman, Nancy; Line, Laura; Hansen-Turton, Tine

    2011-01-01

    Objective Lead exposure in children can lead to neuropsychological impairment. This study tested whether primary prevention interventions in the newborn period prevent elevated blood lead levels (BLLs). Methods The Philadelphia Lead Safe Homes (LSH) Study offered parental education, home evaluation, and lead remediation to the families of urban newborns. Households were randomized to a standard lead education group or maintenance education group. We conducted home visits at baseline, six months, and 12 months. To compare BLLs, we identified a matched comparison group. Results We enrolled and randomized 314 newborns in the intervention component; 110 completed the study. There were few significant differences between the randomized groups. In the combined intervention groups, positive results on visual inspection declined from baseline to 12 months (97.0% to 90.6%, p=0.007). At baseline, 36.9% of homes were above the U.S. Environmental Protection Agency's lead dust standard, compared with 26.9% at 12 months (p=0.032), mainly due to a drop in windowsill dust levels. Both groups showed a significant increase in parental scores on a lead education test. Children in the intervention and matched control groups had similar geometric mean initial BLLs (2.6 vs. 2.7, p=0.477), but a significantly higher percentage of children in the intervention group had an initial blood lead screening compared with those in the matched group (88.9% vs. 84.4%, p=0.032). Conclusions A study of primary prevention of lead exposure showed a higher blood lead screening rate for the combined intervention groups and mean BLLs at one year of age not statistically different from the comparison group. Most homes had lead hazards. Lead education significantly increased knowledge. PMID:21563715

  4. Protoporphyrin (FEP/ZPP) screening in industrial lead exposure

    SciTech Connect

    Saryan, L.A.

    1988-11-01

    Lead-acid battery manufacturers, as a group, are among the largest industrial users of lead in the United States, and every industry using this metal is confronted with a maze of federal regulations governing workplace conditions and employee health. In the biological testing category, particular emphasis has been placed on the periodic testing of blood for lead, to assess absorption of the metal, and protoporphyrin (abbreviated ZPP or FEP) testing as a means of monitoring the biological effects resulting from lead exposure. The protoporphyrin test, however, remains a matter of general confusion among industry managers and medical directors, and this article attempts to provide a concise and understandable explanation of this topic. 10 references, 3 figures, 1 table.

  5. Peripheral blood findings associated with asymptomatic lead exposure

    SciTech Connect

    Day, C.M.; Tennant, F.S. Jr.

    1982-02-01

    This study was done to determine whether erythroid alterations can be found on a peripheral blood smear from an asymptomatic person exposure to excess atmospheric lead. Thirty healthy, asymptomatic adults who lived within five miles of a major Los Angeles, California freeway for five consecutive years were studied. Erythroid cytologic alterations-including-anisocytosis, poikilocytosis, polychromasia and basophilic stippling were statistically associated with increased free erythrocyte protoporphyrin levels. These findings indicate that erythroid alterations may be found on a peripheral blood smear prior to the development of clinical symptoms of lead intoxication.

  6. Exposure to lead in South African shooting ranges.

    PubMed

    Mathee, Angela; de Jager, Pieter; Naidoo, Shan; Naicker, Nisha

    2017-02-01

    Lead exposure in shooting ranges has been under scrutiny for decades, but no information in this regard is available in respect of African settings, and in South Africa specifically. The aim of this study was to determine the blood lead levels in the users of randomly selected private shooting ranges in South Africa's Gauteng province. An analytical cross sectional study was conducted, with participants recruited from four randomly selected shooting ranges and three archery ranges as a comparator group. A total of 118 (87 shooters and 31 archers) were included in the analysis. Shooters had significantly higher blood lead levels (BLL) compared to archers with 36/85 (42.4%) of shooters versus 2/34 (5.9%) of archers found to have a BLL ≥10μg/dl (p<0.001). Shooting ranges may constitute an import site of elevated exposure to lead. Improved ventilation, low levels of awareness of lead hazards, poor housekeeping, and inadequate personal hygiene facilities and practices at South African shooting ranges need urgent attention. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  7. Elevated blood lead levels from exposure via a radiator workshop.

    PubMed

    Treble, R G; Thompson, T S; Morton, D N

    1998-04-01

    Elevated lead levels were discovered in blood samples collected from family members where both the father and the mother worked in a radiator repair workshop. The father and mother were found to have blood lead levels of 2.0 and 0.5 mumol/L (41.7 and 10.4 micrograms/dL), respectively. The father's blood lead level was just below the Canadian occupational health and safety intervention level (2.5 mumol/L or 52.1 micrograms/dL). The two children had blood lead levels of 1.0 and 0.8 mumol/L (20.8 and 16.7 micrograms/dL), both of which are in excess of the recommended guideline for intervention in the case of children (0.5 mumol/L or 10.4 micrograms/dL). The exposure of the two children was possibly due to a combination of pathways including exposure at the workshop itself during visits and also the transportation of lead-containing dust to the home environment.

  8. Cumulative exposure ages of Libyan desert glass determined from in situ production of /sup 10/Be and /sup 26/Al

    SciTech Connect

    Giegengack, R.; Klein, J.; Middleton, R.; Sharma, P.; Underwood, J.R. Jr.; Weeks, R.A.

    1985-01-01

    Libyan Desert Glass (LDG), a unique high-silica natural glass of unknown origin from the Western Desert of Egypt, has been distributed across at least 3500 km/sup 2/ of desert surface during a period of erosional lowering of that landscape that may have prevailed for much of the time since the glass was formed 28.5 m.y. ago; a minimum of 1.4 x 10/sup 9/ g of glass has survived that erosional process. All specimens examined in the course of three field investigations are interpreted to have been carried to their present positions by stream transportation or by the hand of early man. Two dozen samples were selected for measurement of the abundance of /sup 10/Be and /sup 26/Al produced in situ by cosmic-ray interaction with LDG. /sup 26/Al//sup 10/Be ratios >1 support the conclusion that these nuclides have been produced at the Earth's surface by spallation reactions within the glass itself, and that individual pieces have experienced disparate histories of exposure to cosmic rays. From models of cosmic-ray flux and from /sup 10/Be and /sup 26/Al concentrations and ratios, the authors have calculated that specimens of LDG have lain exposed to cosmic rays for cumulative periods of time ranging from 200,000 to the order of 10/sup 6/ years during the last 6 million years.

  9. Early (in uterus and infant) exposure to mercury and lead.

    PubMed

    Dorea, Jose G; Donangelo, Carmen M

    2006-06-01

    Mercury and lead are toxic metals widely spread in the environment with bio-accumulative features that raises public health concerns. Both metals are equally dispersed in the human food chain but exposure and risk of toxicity during early human development are modulated by the diet and nutritional status. Understanding how Hg and Pb occur and interact with nutrients is fundamental to establish guidelines for diminishing exposure and the risk of toxicity. The risk of fetal and infant exposure to Hg can be influenced by maternal amalgam filling (inorganic Hg) and fish consumption (monomethyl Hg), whereas the risk of exposure to Pb is complex: maternal absorption depends on nutrient interactions (Ca and P); and maternal body Pb accumulation responds to all factors known to interact with bone and calcium metabolism. Maternal exposure to Hg and Pb is more important during fetal development than during breastfeeding. Moreover, these metals (especially Pb) are frequently higher in infant formulas which do not carry the nutritional and psychological advantages and protection of breastfeeding. Infant's reference dose is lower for Hg than for Pb, but risk of Pb contamination for fetuses and infant (breast- or formula-fed) is higher and lasts longer than Hg. Breastfeeding is essential to complete infant development. Interruption or suppression of breast-feeding with cow's milk-based formulas is not an option to environmental pollution.

  10. Methods for integrated exposure monitoring of lead and cadmium

    SciTech Connect

    Vahter, M.; Berglund, M.; Friberg, L. ); Slorach, S. ); Saric, M. ); Zheng Xingquan ); Fujita, Masahiko )

    1991-10-01

    An international pilot monitoring study on exposure to lead (Pb) and cadmium (Cd) has been implemented in Beijing, Yokohama, Stockholm, and Zagreb as part of the UNEP/WHO human exposure assessment locations (HEAL) Program. The main objective was to develop and test methods, including methods for quality assurance, for monitoring of personal exposure to Pb and Cd. The study included analytical training for Pb and Cd in blood, air filters, dust, diets, and feces, as well as exposure monitoring activities in small groups of nonsmoking women, 23-53 years of age, during 7 consecutive days. Airborne particulates, duplicate diets, feces, and blood were collected. An extensive quality assurance program was implemented in order to assure the reliability and comparability of the monitoring data. The main problem in the sample collection was associated with the air monitoring. The pumps were noisy, and the batteries had to be recharged every 6-8 hr. Collection of duplicate diets during 1 week gave good estimates of average dietary intakes of Pb and Cd. The metal contents in feces were found useful for evaluation of total peroral intakes. The methods used made it possible to demonstrate that the diet was the main source of Cd exposure at all the HEAL sites.

  11. Urban adolescent mothers exposed to community, family, and partner violence: is cumulative violence exposure a barrier to school performance and participation?

    PubMed

    Kennedy, Angie C; Bennett, Larry

    2006-06-01

    Using a risk and resilience perspective, the authors assessed urban adolescent mothers' exposure to community, family, and partner violence and analyzed the relationships between cumulative violence exposure and multiple school outcomes, within the context of welfare reforms. Positive attitude toward school and social support were examined as moderators of violence exposure on school outcomes. The authors pilot tested the questionnaire with 10 participants, then surveyed 120 adolescent mothers regarding their violence exposure, school performance and participation, positive attitude toward school, and social support. Results indicate very high rates of lifetime exposure to violence; intercorrelations and regression analyses indicate that as violence exposure increases, school outcomes tend to worsen, with positive attitude toward school found to be a significant moderator of the effects of exposure to community violence on behavior problems in school. Implications for researchers, practitioners, school policies and programs, and welfare policies and programs conclude the article.

  12. Radiation dose from common radiological investigations and cumulative exposure in children with cystic fibrosis: an observational study from a single UK centre.

    PubMed

    Ward, Rebecca; Carroll, William D; Cunningham, Paula; Ho, Sheng-Ang; Jones, Mary; Lenney, Warren; Thompson, David; Gilchrist, Francis J

    2017-08-21

    Cumulative radiation exposure is associated with increased risk of malignancy. This is important in cystic fibrosis (CF) as frequent imaging is required to monitor disease progression and diagnose complications. Previous estimates of cumulative radiation are outdated as the imaging was performed on older equipment likely to deliver higher radiation. Our objectives were to determine the radiation dose delivered to children during common radiological investigations using modern equipment and to identify the number of such investigations performed in a cohort of children with CF to calculate their cumulative radiation exposure. Data including age at investigation and radiation exposure measured as estimated effective dose (EED) were collected on 2827 radiological studies performed on children at one UK paediatric centre. These were combined with the details of all radiological investigations performed on 65 children with CF attending the same centre to enable calculation of each child's cumulative radiation exposure. The mean EED for the common radiological investigations varied according to age. The range was 0.01-0.02 mSv for chest X-rays, 0.03-0.11 mSv for abdominal X-rays, 0.57-1.69 mSv for CT chest, 2.9-3.9 mSv for abdominal and pelvic CT, 0.20-0.21 mSv for sinus CT and 0.15-0.52 mSv for fluoroscopy-guided procedures. The mean EED was three to five times higher for helical compared with axial chest CT scans. The mean annual cumulative EED for our cohort of children with CF was 0.15 mSv/year with an estimated cumulative paediatric lifetime EED (0-18 years) of 3.5 mSv. This study provides up-to-date estimations of the radiation exposure when using common radiological investigations. These doses and the estimates of cumulative radiation exposure in children with CF are lower than previously reported. This reflects the reduced EED associated with modern equipment and the use of age-specific scanning protocols. © Article author(s) (or their employer

  13. Prevalence of elevated blood leads and exposure to lead in construction trades in Iowa and Illinois.

    PubMed

    Reynolds, S J; Seem, R; Fourtes, L J; Sprince, N L; Johnson, J; Walkner, L; Clarke, W; Whitten, P

    1999-08-01

    Despite lowering of the permissible exposure level for lead in construction from 200 to 50 microg/m3 in 1993, excessive lead exposure continues to be a problem. Relatively little data are available from the Midwestern U.S. on the environmental lead concentrations generated during various construction activities and the potential for worker exposure. This study characterized the prevalence of blood lead concentrations in high-risk construction trades in Iowa/Illinois, and identified risk factors for occupational exposure to lead in these construction workers. A sample of 459 workers was selected from the total population of all union members from trade groups of painters, plumbers/pipefitters, ironworkers, laborers, and electricians. Participants completed an interviewer-administered questionnaire obtaining information on demographics, symptoms, occupational history, work practices, personal protective equipment, and training. Venous blood samples were collected from each participant and analyzed for blood lead (using atomic absorption spectroscopy) and free erythrocyte protoporphyrin levels. Blood lead levels (BLLs) of construction workers ranged from 0.1 to 50 microg/dL. Geometric mean blood lead concentrations by trade group were: laborers (7.6 microg/dL, n = 80); painters (5.9 microg/dL, n = 83); ironworkers (5.2 microg/dL, n = 87); plumbers (4.4 microg/dL, n = 82); electricians (2.4 microg/dL, n = 91). Blood lead levels for painters and laborers were significantly higher than other trade groups, and levels for electricians were significantly lower (p < 0. 01). Participants reported working primarily on commercial and industrial projects including new construction, renovation, and demolition. There were significant differences between the types of projects performed by different trade groups with laborers performing more highway/bridge renovation (p < 0.01), and plumbers reporting more residential remodeling (p = 0.05), repair of water lines containing lead (p

  14. Reproductive toxicity of low-level lead exposure in men

    SciTech Connect

    Telisman, Spomenka Colak, Bozo; Pizent, Alica; Jurasovic, Jasna; Cvitkovic, Petar

    2007-10-15

    Parameters of semen quality, seminal plasma indicators of secretory function of the prostate and seminal vesicles, sex hormones in serum, and biomarkers of lead, cadmium, copper, zinc, and selenium body burden were measured in 240 Croatian men 19-52 years of age. The subjects had no occupational exposure to metals and no known other reasons suspected of influencing male reproductive function or metal metabolism. After adjusting for age, smoking, alcohol, blood cadmium, and serum copper, zinc, and selenium by multiple regression, significant (P<0.05) associations of blood lead (BPb), {delta}-aminolevulinic acid dehydratase (ALAD), and/or erythrocyte protoporphyrin (EP) with reproductive parameters indicated a lead-related increase in immature sperm concentration, in percentages of pathologic sperm, wide sperm, round sperm, and short sperm, in serum levels of testosterone and estradiol, and a decrease in seminal plasma zinc and in serum prolactin. These reproductive effects were observed at low-level lead exposure (BPb median 49 {mu}g/L, range 11-149 {mu}g/L in the 240 subjects) common for general populations worldwide. The observed significant synergistic effect of BPb and blood cadmium on increasing serum testosterone, and additive effect of a decrease in serum selenium on increasing serum testosterone, may have implications on the initiation and development of prostate cancer because testosterone augments the progress of prostate cancer in its early stages.

  15. Prenatal cocaine exposure: the role of cumulative environmental risk and maternal harshness in the development of child internalizing behavior problems in kindergarten.

    PubMed

    Eiden, Rina D; Godleski, Stephanie; Colder, Craig R; Schuetze, Pamela

    2014-01-01

    This study examined the associations between prenatal exposure to cocaine and other substances and child internalizing behavior problems at kindergarten. We investigated whether maternal harshness or cumulative environmental risk mediated or moderated this association. Participants consisted of 216 (116 cocaine exposed, 100 non-cocaine exposed) mother-infant dyads participating in an ongoing longitudinal study of prenatal cocaine exposure. Results indicated that, as hypothesized, maternal harshness moderated the association between prenatal cocaine exposure to child internalizing in kindergarten such that prenatal cocaine exposure increased risk for internalizing problems at high levels of maternal harshness from 7 to 36months and decreased risk at low levels of harshness. Contrary to hypothesis, the association between prenatal cocaine exposure and child internalizing in kindergarten was not mediated by maternal harshness or cumulative environmental risk. However, cumulative environmental risk (from 1month of child age to kindergarten) was predictive of child internalizing behavior problems at kindergarten. Results have implications for parenting interventions that may be targeted toward reducing maternal harshness in high risk samples characterized by maternal substance use in pregnancy.

  16. Environmental lead exposure as a risk for childhood aplastic anemia.

    PubMed

    Ahamed, M; Akhtar, M J; Verma, S; Kumar, A; Siddiqui, M K J

    2011-01-01

    Concern about environmental lead exposure as a significant public health threat has increased as evidence has accumulated regarding adverse health effects at successively lower levels. Aplastic anemia is a hematological disorder of unknown etiology with a high lethality rate. Lead is a known toxicant for the hematopoietic system. Oxidative stress appears to be the possible mode of lead toxicity. We evaluated the effects of blood lead level on oxidative stress parameters in children suffering from aplastic anemia disease. Seventeen children with aplastic anemia disease (15 male and 2 female, age 3-12 y) were recruited in the study group. Fifty one healthy children (45 male and 6 female, age 3-12 y) having normal blood profiles and not suffering from any chronic disease(s) were used as controls. Blood lead level and oxidative stress parameters were determined. Mean blood lead level was significantly higher while δ-aminolevulinic acid dehydratase (δ-ALAD) activity, a biomarker for lead exposure was significantly lower in the study group as compared to the control group (p < 0.05 for each). Thiobarbituric acid reactive species (TBARS), a marker of lipid peroxidation, was significantly higher while the antioxidant glutathione (GSH) level was significantly lower in the study group as compared to the control group (p < 0.05 for each). Activity of the antioxidant enzyme catalase (CAT) was significantly higher in the study group than in the control group (p < 0.05). There was a significant negative correlation of blood lead levels with δ-ALAD (r = -0.45; p < 0.05) and GSH (r = -0.32; p < 0.05), and a positive correlation with TBARS (r = 0.41; p < 0.05) and CAT (r = 0.37; p < 0.05). Although a causal pathway cannot be determined from this study, our results indicated that lead induces oxidative stress in children suffering from aplastic anemia. Lead-induced oxidative stress as an underlying mechanism for aplastic anemia warrants further research.

  17. Vibration perception thresholds in workers with long term exposure to lead

    PubMed Central

    Chuang, H.; Schwartz, J.; Tsai, S.; Lee, M.; Wang, J.; Hu, H.

    2000-01-01

    OBJECTIVES—To evaluate the impact of long term occupational exposure to lead on function of the peripheral nervous system as reflected by vibration perception threshold (VPT), measured with a portable vibrameter.
METHODS—217 Workers in a lead battery factory were required to have an annual blood lead measurement during each of the 5 years preceding this study. All were invited to take the VPT test. A total of 206 workers were studied. The associations were analysed between VPTs and current blood lead concentration, mean concentration of blood lead over the past 5 years, maximum blood lead concentration during the past 5 years, index of cumulative blood lead (ICL), time weighted index of cumulative blood lead (TWICL), and percentage of lifespan spent at work in the plant, as well as the other potential confounders. Ordinary multiple regressions, generalised additive models, and hockey stick regression analyses were used to explore the potential existence of a threshold effect of blood lead variables on VPT.
RESULTS—VPT at a frequency of 220 Hz ranged from 6 to 100 (10-2 g, or 0.098 m/s2) with a mean (SD) of 19.8 (14.2) for the feet and from 4 to 43 with a mean (SD) of 10.2 (6.1) for the hands. The five variables of exposure to lead were all significantly correlated with VPT of the feet but not the hands. In multiple linear regression analyses, the mean of the blood lead concentrations and the TWICL were significantly associated with VPT of the feet. The relation between VPT of the feet and mean blood lead was shown to be a J shaped curve with a generalised additive model and local smoothing technique. In the hockey stick regression, evidence was found of a threshold effect at a mean blood lead concentration of 31 µg/dl. Above this threshold it was estimated that each increase of 1 µg/dl mean blood lead over 5 years would increase VPT of the feet by 0.29 (10-2 g) or 0.028 m/s2 (at a frequency of 220 Hz) with other potential confounders

  18. Cumulative trauma and midlife well-being in American women who served in Vietnam: effects of combat exposure and postdeployment social support.

    PubMed

    Park, Crystal L; Wachen, Jennifer Schuster; Kaiser, Anica Pless; Mager Stellman, Jeanne

    2015-01-01

    Research increasingly demonstrates that trauma exposure can have cumulative effects, yet much remains to be learned about effects of cumulative trauma, particularly regarding longer term adjustment. One such trauma, combat exposure, is insufficiently understood, especially for women, who are increasingly engaged in professional combat activities. The study comprised a cross-sectional survey assessing multiple aspects of current well-being in women approximately 25 years after their service in Vietnam during the Vietnam War. Participants were 1374 women (78% military and 22% nonmilitary; mean age = 59.7). This study investigated the relations between three separate categories of trauma exposure (childhood, adulthood, and combat) and well-being and examined whether perceived social support at return from Vietnam moderated the association between combat exposure and well-being. While both childhood and adulthood trauma exposure related to midlife well-being, combat exposure still uniquely predicted outcomes. Further, postdeployment perceived social support moderated the association of combat and well-being: recollected higher perceived social support at homecoming buffered participants from the links between combat exposure and well-being. These results may have important implications for interventions to reduce the impact of traumatic experiences, particularly in light of the increasing exposure of women to direct combat events.

  19. Cumulative Retrospective Exposure Assessment (REA) as a predictor of amphibole asbestos lung burden: validation procedures and results for industrial hygiene and pathology estimates

    PubMed Central

    Roggli, Victor L.; Boelter, Fred W.; Rasmuson, Eric J.; Redinger, Charles F.

    2014-01-01

    Context A detailed evaluation of the correlation and linearity of industrial hygiene retrospective exposure assessment (REA) for cumulative asbestos exposure with asbestos lung burden analysis (LBA) has not been previously performed, but both methods are utilized for case-control and cohort studies and other applications such as setting occupational exposure limits. Objective (a) To correlate REA with asbestos LBA for a large number of cases from varied industries and exposure scenarios; (b) to evaluate the linearity, precision, and applicability of both industrial hygiene exposure reconstruction and LBA; and (c) to demonstrate validation methods for REA. Methods A panel of four experienced industrial hygiene raters independently estimated the cumulative asbestos exposure for 363 cases with limited exposure details in which asbestos LBA had been independently determined. LBA for asbestos bodies was performed by a pathologist by both light microscopy and scanning electron microscopy (SEM) and free asbestos fibers by SEM. Precision, reliability, correlation and linearity were evaluated via intraclass correlation, regression analysis and analysis of covariance. Plaintiff’s answers to interrogatories, work history sheets, work summaries or plaintiff’s discovery depositions that were obtained in court cases involving asbestos were utilized by the pathologist to provide a summarized brief asbestos exposure and work history for each of the 363 cases. Results Linear relationships between REA and LBA were found when adjustment was made for asbestos fiber-type exposure differences. Significant correlation between REA and LBA was found with amphibole asbestos lung burden and mixed fiber-types, but not with chrysotile. The intraclass correlation coefficients (ICC) for the precision of the industrial hygiene rater cumulative asbestos exposure estimates and the precision of repeated laboratory analysis were found to be in the excellent range. The ICC estimates were performed

  20. Maternal self-esteem, exposure to lead, and child neurodevelopment.

    PubMed

    Surkan, Pamela J; Schnaas, Lourdes; Wright, Rosalind J; Téllez-Rojo, Martha M; Lamadrid-Figueroa, Héctor; Hu, Howard; Hernández-Avila, Mauricio; Bellinger, David C; Schwartz, Joel; Perroni, Estela; Wright, Robert O

    2008-03-01

    The notion that maternal personality characteristics influence cognitive development in their children has been grounded in stress moderation theory. Maternal personality traits, such as self-esteem, may buffer maternal stressors or lead to improved maternal-child interactions that directly impact neurodevelopment. This can be extended to suggest that maternal personality may serve to attenuate or exacerbate the effects of other neurotoxicants, although this has not been studied directly. We examined whether mothers' self-esteem had a direct or main effect on their children's cognitive outcomes. We also explored the modifying effects of maternal self-esteem on the association between exposure to lead and neurodevelopment in these children. Study participants included 379 mother-child pairs from Mexico City. Data included the Coopersmith Self-Esteem Scale in mothers, children's Bayley's Scale of Infant Development (BSID) scores, and sociodemographic information. Linear regression was used to model the relationship between maternal self-esteem and the Bayley's Mental Development Index (MDI) and Psychomotor Development Index (PDI) scores at age 24 months using models stratified by levels of maternal self-esteem. In adjusted models, each point increase in maternal self-esteem was associated with children having 0.2 higher score on the Bayley's MDI (p=0.04). Similar results were observed using the PDI outcome. Moreover, there was evidence that maternal self-esteem attenuated the negative effects of lead exposure, although the interaction fell short of conventional levels of statistical significance.

  1. Transcriptome Changes in Hirschfeldia incana in Response to Lead Exposure.

    PubMed

    Auguy, Florence; Fahr, Mouna; Moulin, Patricia; El Mzibri, Mohamed; Smouni, Abdelaziz; Filali-Maltouf, Abdelkarim; Béna, Gilles; Doumas, Patrick

    2015-01-01

    Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb). The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana) and a Pb tolerant plant (H. incana) enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall, and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up-regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies.

  2. Transcriptome Changes in Hirschfeldia incana in Response to Lead Exposure

    PubMed Central

    Auguy, Florence; Fahr, Mouna; Moulin, Patricia; El Mzibri, Mohamed; Smouni, Abdelaziz; Filali-Maltouf, Abdelkarim; Béna, Gilles; Doumas, Patrick

    2016-01-01

    Hirschfeldia incana, a pseudometallophyte belonging to the Brassicaceae family and widespread in the Mediterranean region, was selected for its ability to grow on soils contaminated by lead (Pb). The global comparison of gene expression using microarrays between a plant susceptible to Pb (Arabidopsis thaliana) and a Pb tolerant plant (H. incana) enabled the identification of a set of specific genes expressed in response to lead exposure. Three groups of genes were particularly over-represented by the Pb exposure in the biological processes categorized as photosynthesis, cell wall, and metal handling. Each of these gene groups was shown to be directly involved in tolerance or in protection mechanisms to the phytotoxicity associated with Pb. Among these genes, we demonstrated that MT2b, a metallothionein gene, was involved in lead accumulation, confirming the important role of metallothioneins in the accumulation and the distribution of Pb in leaves. On the other hand, several genes involved in biosynthesis of ABA were shown to be up-regulated in the roots and shoots of H. incana treated with Pb, suggesting that ABA-mediated signaling is a possible mechanism in response to Pb treatment in H. incana. This latest finding is an important research direction for future studies. PMID:26793211

  3. MATERNAL SELF-ESTEEM, EXPOSURE TO LEAD, AND CHILD NEURODEVELOPMENT

    PubMed Central

    Surkan, Pamela J.; Schnaas, Lourdes; Wright, Rosalind J.; Téllez-Rojo, Martha M.; Lamadrid-Figueroa, Héctor; Hu, Howard; Hernández-Avila, E. Mauricio; Bellinger, David C.; Schwartz, Joel; Perroni, Estela; Wright, Robert O.

    2008-01-01

    The notion that maternal personality characteristics influence cognitive development in their children has been grounded in stress moderation theory. Maternal personality traits, such as self-esteem, may buffer maternal stressors or lead to improved maternal-child interactions that directly impact neurodevelopment. This can be extended to suggest that maternal personality may serve to attenuate or exacerbate the effects of other neurotoxicants, although this has not been studied directly. We examined whether mothers’ self-esteem had a direct or main effect on their children's cognitive outcomes. We also explored the modifying effects of maternal self-esteem on the association between exposure to lead and neurodevelopment in these children. Study participants included 379 mother-child pairs from Mexico City. Data included the Coopersmith self-esteem scale in mothers, children's Bayley's Scale of Infant Development (BSID) scores, and sociodemographic information. Linear regression was used to model the relationship between maternal self-esteem and the Bayley's Mental Development Index (MDI) and Psychomotor Development Index (PDI) scores at age 24 months using regression models stratified by levels of maternal self-esteem. In adjusted models, each point increase in maternal self-esteem was associated with children having 0.2 higher score on the Bayley's MDI (p=0.04). Similar results were observed using the PDI outcome. Moreover, there was evidence that maternal self-esteem attenuated the negative effects of lead exposure, although the interaction fell short of conventional levels of statistical significance. PMID:18261800

  4. Radiation exposure benefit of a lead cap in invasive cardiology.

    PubMed

    Kuon, E; Birkel, J; Schmitt, M; Dahm, J B

    2003-10-01

    Occupational head exposure to radiation in cardiologists may cause radiation induced cataracts and an increased risk of brain cancer. To determine the effectiveness of 0.5 mm lead equivalent caps, not previously used in invasive cardiology, in comparison with a 1.0 mm lead equivalent ceiling mounted lead glass screen. An anthropomorphic Alderson-Rando phantom was used to represent the patient. Scatter entrance skin air kerma to the operator position (S-ESAK-O) was measured during fluoroscopy for all standard angulations and the S-ESAK-O per dose-area product (DAP) calculated, as applied to the phantom. Measured mean (SD) left/right anterior oblique angulation ratios of S-ESAK-O without lead devices were 23.1 (10.1), and varied as a function of tube angulation, body height, and angle of incidence. S-ESAK-O/DAP decreased with incremental operator body height by 10 (3)% per 10 cm. A 1.0 mm lead glass shield reduced mean S-ESAK-O/DAP originating from coronary angiography from 1089 (764) to 54 (29) nSv/Gy x cm2. A 0.5 mm lead cap was effective in lowering measured levels to 1.8 (1.1) nSv/Gy x cm2. Both devices together enabled attenuation to 0.5 (0.1) nSv/Gy x cm2. The most advantageous line of vision for protection of the operator's eyes was > or = 60 degrees rightward. Use of 0.5 mm lead caps proved highly effective, attenuating S-ESAK-O to 2.7 (2.0) x 10(-3) of baseline, and to 1.2 (1.4) x 10(-3) of baseline where there was an additional 1.0 mm lead glass shield. These results could vary according to the x ray systems used, catheterisation protocols, and correct use of radiation protection devices.

  5. Early umbilical cord clamping contributes to elevated blood lead levels among infants with higher lead exposure.

    PubMed

    Chaparro, Camila M; Fornes, Raymond; Neufeld, Lynnette M; Tena Alavez, Gilberto; Eguía-Líz Cedillo, Raúl; Dewey, Kathryn G

    2007-11-01

    To investigate whether infant iron status, modified by umbilical cord clamping time and infant feeding mode, affected infant blood lead concentration at 6 months of age. Participants were a subset of women and their infants randomized to receive early (10 seconds) or delayed (2 minutes) umbilical cord clamping and were monitored to 6 months postpartum in Mexico City. Iron and lead status was analyzed in maternal, placental, and 6-month infant blood samples. Baseline maternal lead exposure data and infant feeding data at 2, 4, and 6 months were collected. In the total sample, maternal blood lead concentration, infant ferritin, and breast-feeding practices predicted infant blood lead concentration. Among infants with higher placental blood lead concentration and breast-fed infants not receiving any iron-fortified formula or milk at 6 months, early clamping increased infant blood lead concentration, an effect mediated in part via decreased infant iron status. Early cord clamping, by decreasing infant iron status, contributes to higher blood lead concentrations at 6 months of age among infants at high risk.

  6. [Use of urine lead level as an exposure indicator and its relationship to blood lead].

    PubMed

    Moreira, Maria de Fátima Ramos; Neves, Eduardo Borba

    2008-09-01

    The aim of this work was to verify whether there are statistically significant correlation between the concentrations of lead in blood (Pb-B) and urine (Pb-U). Electrothermal atomic absorption spectrometry was used in the determination of lead concentration in biological material. Venous blood and spot urine were collected from workers occupationally exposed (95), adults (130) and children up to 15 years old (22) environmentally exposed. After a test showing significant differences between Pb-U and the three categories previously determined, cutting points for Pb-U were established to predict Pb-B values by the ROC curve. Thus, it is expected that Pb-B is lower than 10 microg.dL-(1) with Pb-U up to 0.55 microg.dL-(1), whereas lead levels in blood below 27.6 microg.dL-(1) are expected when the amount of the metal in urine is lower than 2.05 microg.dL-(1). So, urine can be used to replace blood for the assessment of the occupational exposure to lead. However, caution is advised in the case of environmental exposure, since urinary lead should be used just as an estimation of the metal content in blood.

  7. The social costs of childhood lead exposure in the post-lead regulation era.

    PubMed

    Muennig, Peter

    2009-09-01

    To estimate the benefits that might be realized if all children in the United States had a blood lead level of less than 1 microg/dL. Data were obtained from published and electronic sources. A Markov model was used to project lifetime earnings, reduced crime costs, improvements in health, and reduced welfare costs using 2 scenarios: (1) maintaining the status quo and (2) reducing the blood lead level of all children to less than 1 microg/dL. The cohort of US children between birth and age 6 years in 2008, with economic and health outcomes projected for 65 years. Increased primary prevention efforts aimed at reducing lead exposure among children and pregnant women. Societal costs and quality-adjusted life years (QALYs) gained. Reducing blood lead levels to less than 1 microg/dL among all US children between birth and age 6 years would reduce crime and increase on-time high school graduation rates later in life. The net societal benefits arising from these improvements in high school graduation rates and reductions in crime would amount to $50 000 (SD, $14 000) per child annually at a discount rate of 3%. This would result in overall savings of approximately $1.2 trillion (SD, $341 billion) and produce an additional 4.8 million QALYs (SD, 2 million QALYs) for US society as a whole. More aggressive programs aimed at reducing childhood lead exposure may produce large social benefits.

  8. Occupational Lead Exposure from Indoor Firing Ranges in Korea.

    PubMed

    Park, Won-Ju; Lee, Suk-Ho; Lee, Se-Ho; Yoon, Hye-Sik; Moon, Jai-Dong

    2016-04-01

    Military personnel often use ammunitions that contain lead. The present study aimed to identify the risks for lead exposure and lead poisoning among workers at indoor firing ranges. A special health examination, including blood lead level (BLL) testing, was performed for all 120 workers at the indoor firing ranges of the Republic of Korea's Air Force, Navy, and Armed Forces Athletic Corps. The overall mean BLL was 11.3 ± 9.4 µg/dL (range: 2.0-64.0 µg/dL). The arithmetic mean of the BLL for professional shooters belong to Armed Forces Athletic Corps was 14.0 ± 8.3 µg/dL, while those of shooting range managers and shooting range supervisors were 13.8 ± 11.1 µg/dL and 6.4 ± 3.1 µg/dL, respectively. One individual had a BLL of 64 µg/dL, and ultimately completed chelation treatment (with CaNa2-ethylenediaminetetraacetic acid) without any adverse effects. These findings indicate that indoor firing range workers are exposed to elevated levels of lead. Therefore, when constructing an indoor firing range, a specialist should be engaged to design and assess the ventilation system; and safety guidelines regarding ammunition and waste handling must be mandatory. Moreover, workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations.

  9. Occupational Lead Exposure from Indoor Firing Ranges in Korea

    PubMed Central

    Lee, Suk-Ho; Lee, Se-Ho; Yoon, Hye-Sik

    2016-01-01

    Military personnel often use ammunitions that contain lead. The present study aimed to identify the risks for lead exposure and lead poisoning among workers at indoor firing ranges. A special health examination, including blood lead level (BLL) testing, was performed for all 120 workers at the indoor firing ranges of the Republic of Korea’s Air Force, Navy, and Armed Forces Athletic Corps. The overall mean BLL was 11.3 ± 9.4 µg/dL (range: 2.0–64.0 µg/dL). The arithmetic mean of the BLL for professional shooters belong to Armed Forces Athletic Corps was 14.0 ± 8.3 µg/dL, while those of shooting range managers and shooting range supervisors were 13.8 ± 11.1 µg/dL and 6.4 ± 3.1 µg/dL, respectively. One individual had a BLL of 64 µg/dL, and ultimately completed chelation treatment (with CaNa2-ethylenediaminetetraacetic acid) without any adverse effects. These findings indicate that indoor firing range workers are exposed to elevated levels of lead. Therefore, when constructing an indoor firing range, a specialist should be engaged to design and assess the ventilation system; and safety guidelines regarding ammunition and waste handling must be mandatory. Moreover, workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations. PMID:27051231

  10. A comparison of peak vs cumulative physical work exposure risk factors for the reporting of low back pain in the automotive industry.

    PubMed

    Norman, R.; Wells, R.; Neumann, P.; Frank, J.; Shannon, H.; Kerr, M.

    1998-12-01

    OBJECTIVE: To determine the relative importance of modelled peak spine loads, hand loads, trunk kinematics and cumulative spine loads as predictors of reported low back pain (LBP). BACKGROUND: The authors have recently shown that both biomechemical and psychosocial variables are important in the reporting of LBP. In previous studies, peak spinal load risk factors have been identified and while there is in vitro evidence for adverse effects of excessive cumulative load on tissue, there is little epidemiological evidence. METHODS: Physical exposures to peak and cumulative lumbar spine moment, compression and shear forces, trunk kinematics, and forces on hands were analyzed on 130 randomly selected controls and 104 cases. Univariable and multivariable odds ratios of the risk of reporting were calculated from a backwards logistic regression analysis. Interrelationships among variables were examined by factor analysis. RESULTS: Cases showed significantly higher loading on all biomechanical variables. Four independent risk factors were identified: integrated lumbar moment (over a shift), 'usual' hand force, peak shear force at the level of L(4)/L(5) and peak trunk velocity. Substituting lumbar compression or moment for shear did not appreciably alter odds ratios because of high correlations among these variables. CONCLUSIONS: Cumulative biomechanical variables are important risk factors in the reporting of LBP. Spinal tissue loading estimates from a biomechanical model provide information not included in the trunk kinematics and hand force inputs to the model alone. Workers in the top 25% of loading exposure on all risk factors are at about six times the risk of reporting LBP when compared with those in the bottom 25%. RELEVANCE: Primary prevention, treatment, and return to work efforts for individuals reporting LBP all require understanding of risk factors. The results suggest that cumulative loading of the low back is important etiologically and highlight the need for

  11. Lead exposure at firing ranges-a review.

    PubMed

    Laidlaw, Mark A S; Filippelli, Gabriel; Mielke, Howard; Gulson, Brian; Ball, Andrew S

    2017-04-04

    Lead (Pb) is a toxic substance with well-known, multiple, long-term, adverse health outcomes. Shooting guns at firing ranges is an occupational necessity for security personnel, police officers, members of the military, and increasingly a recreational activity by the public. In the United States alone, an estimated 16,000-18,000 firing ranges exist. Discharge of Pb dust and gases is a consequence of shooting guns. The objectives of this study are to review the literature on blood lead levels (BLLs) and potential adverse health effects associated with the shooting population. The search terms "blood lead", "lead poisoning", "lead exposure", "marksmen", "firearms", "shooting", "guns", "rifles" and "firing ranges" were used in the search engines Google Scholar, PubMed and Science Direct to identify studies that described BLLs in association with firearm use and health effects associated with shooting activities. Thirty-six articles were reviewed that included BLLs from shooters at firing ranges. In 31 studies BLLs > 10 μg/dL were reported in some shooters, 18 studies reported BLLs > 20 μg/dL, 17 studies > 30 μg/d, and 15 studies BLLs > 40 μg/dL. The literature indicates that BLLs in shooters are associated with Pb aerosol discharge from guns and air Pb at firing ranges, number of bullets discharged, and the caliber of weapon fired. Shooting at firing ranges results in the discharge of Pb dust, elevated BLLs, and exposures that are associated with a variety of adverse health outcomes. Women and children are among recreational shooters at special risk and they do not receive the same health protections as occupational users of firing ranges. Nearly all BLL measurements compiled in the reviewed studies exceed the current reference level of 5 μg/dL recommended by the U.S. Centers for Disease Control and Prevention/National Institute of Occupational Safety and Health (CDC/NIOSH). Thus firing ranges, regardless of type and user classification

  12. End-stage renal disease after occupational lead exposure: 20 years of follow-up.

    PubMed

    Evans, Marie; Discacciati, Andrea; Quershi, Abdul Rashid; Åkesson, Agneta; Elinder, Carl-Gustaf

    2017-06-01

    Whether low-level exposure to lead may give rise to chronic kidney disease or end-stage renal disease (ESRD) is debated. In this study, we aimed to specifically investigate if low-level occupational exposure to lead was associated with increased incidence of ESRD. The incidence of starting renal replacement therapy as a result of ESRD was examined in a cohort of10 303 lead-workers who had controlled blood lead concentrations due to a compulsory occupational health surveillance programme in Sweden during the time period 1977-1990. The ESRD incidence (obtained through register-linkage) among the lead-exposed workers was compared with the age, sex and calendar period-adjusted expected incidence based on data from the Swedish renal registry. Dose-response association was evaluated in external (general population) and internal (within the occupational cohort) comparisons by highest achieved blood lead level. There were 30 (0.29%) individuals in the cohort who developed ESRD during the median follow-up period of 26.3 years. The standardised incidence ratio (SIR) for ESRD incidence was 0.79 (95% CI 0.54 to 1.13). Among those who achieved the highest blood lead (>41.4 µg/dL), the SIR was 1.01 (0.44 to 1.99). There was no evidence of a dose-response relationship between the maximum achieved blood lead or the cumulative blood lead exposure and ESRD in external or internal comparisons. This study of workers with documented occupational lead exposures followed for 20 years shows no statistically significant association between lead exposure (following the current occupational recommendations for Sweden) and ESRD. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. Impact of chronic lead exposure on selected biological markers.

    PubMed

    Jangid, Ambica P; John, P J; Yadav, D; Mishra, Sandhya; Sharma, Praveen

    2012-01-01

    Lead poisoning remains a major problem in India due to the lack of awareness of its ill effects among the clinical community. Blood lead, δ-aminolevulinic acid dehydratase (δ-ALAD) and zinc protoporphyrin (ZPP) concentrations are widely used as biomarkers for lead toxicity The present study was designed to determine the impact of chronic lead exposure on selected biological markers. A total of 250 subjects, of both sexes, ranging in age from 20 to 70 years, were recruited. On the basis of BLLs, the subjects were categorized into four groups: Group A (BLL: 0-10 μg/dl), Group B (BLL: 10-20 μg/dl). Group C (BLL: 20-30 μg/dl) and Group D (BLL: 30-40 μg/dl) having BLLs of 3.60 ± 2.71 μg/dl, 15.21 ± 2.65 μg/dl, 26.82 ± 2.53 μg/dl and 36.38 ± 2.83 μg/dl, respectively. Significant changes in biological markers due to elevated BLLs were noted. The relation of BLL and biological markers to demographic characteristics such as sex, habits, diet and substances abuse (smoking effect) were also studied in the present investigation. Males, urban population, non-vegetarians, and smokers had higher blood lead levels. δ-ALAD activity was found to be significantly lower with increased BLL (P < 0.001), while the ZPP level was significantly higher with increased BLL (P < 0.001). Further, BLL showed a negative correlation with δ-ALAD (r = -0.425, P < 0.001, N = 250) and a positive correlations with ZPP (r = 0.669, P < 0.001, N = 250). Chronic lead exposure affects the prooxidant-antioxidant equilibrium leading to cellular oxidative stress.

  14. Alzheimer’s Disease and Environmental Exposure to Lead: The Epidemiologic Evidence and Potential Role of Epigenetics

    PubMed Central

    Bakulski, Kelly M.; Rozek, Laura S.; Dolinoy, Dana C.; Paulson, Henry L.; Hu, Howard

    2013-01-01

    Several lines of evidence indicate that the etiology of late-onset Alzheimer’s disease (LOAD) is complex, with significant contributions from both genes and environmental factors. Recent research suggests the importance of epigenetic mechanisms in defining the relationship between environmental exposures and LOAD. In epidemiologic studies of adults, cumulative lifetime lead (Pb) exposure has been associated with accelerated declines in cognition. In addition, research in animal models suggests a causal association between Pb exposure during early life, epigenetics, and LOAD. There are multiple challenges to human epidemiologic research evaluating the relationship between epigenetics, LOAD, and Pb exposure. Epidemiologic studies are not well-suited to accommodate the long latency period between exposures during early life and onset of Alzheimer’s disease. There is also a lack of validated circulating epigenetics biomarkers and retrospective biomarkers of Pb exposure. Members of our research group have shown bone Pb is an accurate measurement of historical Pb exposure in adults, offering an avenue for future epidemiologic studies. However, this would not address the risk of LOAD attributable to early-life Pb exposures. Future studies that use a cohort design to measure both Pb exposure and validated epigenetic biomarkers of LOAD will be useful to clarify this important relationship. PMID:22272628

  15. Lifestyles, diets, and Native American exposure factors related to possible lead exposures and toxicity.

    PubMed

    Harris, S; Harper, B L

    2001-06-01

    Lead exposure is still a national concern, and it is possible that Native Americans who live on reservations and pursue traditional lifestyles may be at higher risk through both their unique exposure profiles and their potentially greater sensitivity. A major component of the exposure assessment is the diet. For tribal members, traditional lifestyles that include native foods, medicines, and traditional practices have evolved and proven to be the most healthful over many thousands of years of coexistence with the environment. However, a completely traditional diet may not be fully available for a variety of reasons; so, one must also consider the adverse health consequences caused by the loss of healthy native foods and medicines, the contamination of remaining native foods, the inability to practice one's religion, and the possibly lower quality of the substitute diet. Health evaluations of lead exposure on reservations should therefore consider at least two types of diets in addition to the typical suburban diet: (a) traditional diets composed of native foods and medicines that would result in increased exposure if the plants and animals are contaminated and (b) disadvantaged or commodity food diets that result in widespread vitamin and mineral deficits of the sort known to increase absorption of and response to lead. Additional exposure to lead might come from reservation housing which is often older, although the prevalence of lead-based paint on reservations is unknown. The degree of physiological response could also be affected by widespread exposures to other neurotoxins (such as mercury and PCBs in fish), underlying disease patterns, and genetics. Although each of these factors is plausible, their prevalence singly or in combination is unknown. Any correlation between these risk factors and blood lead levels on reservations is also unknown. This paper begins to address these gaps by discussing the range of traditional and current diets that may exist among

  16. Potential Mechanism Leading to Impaired Thermoregulation Following Microgravity Exposure

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.; Etzel, R. A.

    1999-01-01

    Prolonged exposure to microgravity or its analogues impairs thermoregulation in humans evidenced by higher internal temperatures following the exposure during a thermal challenge. Although the mechanism leading to this response has not been clearly delineated, we identified that prolonged head-down tilt (HDT) markedly impairs thermoregulatory reflex control of skin blood flow, as demonstrated by an increased internal temperature threshold for cutaneous vasodilation, and by a reduced slope of the relationship between the elevation in skin blood flow relative to the elevation in internal temperature. Recently, Fortney et al. identified similar responses in two individuals following 115 days of microgravity exposure. One possible mechanism leading to altered cutaneous vasodilation during a thermal challenge following actual or simulated microgravity exposure may be associated with baroreflex-mediated attenuation in the elevation of skin blood flow. During a heat stress the elevation in skin blood flow is accomplished through a combination of increased cutaneous vascular conductance and cardiac output, both of which result in central venous pressure (CVP) decreasing 2-6 mmHg. Reductions in CVP of this magnitude in normothermia decrease muscle blood flow and skin blood flow presumably through unloading the cardiopulmonary baroreceptors. It is unclear whether the reduction in CVP, and accompanying cardiopulmonary baroreceptor unloading, during passive heating buffers the elevation in skin blood flow. That is, would the elevation in skin blood flow be greater if CVP did not decrease, or decreased to a lesser extent during the heat stress? Conversely, if CVP decreased to a greater extend during a thermal challenge following a perturbation such as prolonged HDT, would the elevation in skin blood flow be attenuated during that thermal challenge? Given that prolonged HDT decreases plasma volume and central venous pressure, such a finding would provide a plausible hypothesis

  17. Potential Mechanism Leading to Impaired Thermoregulation Following Microgravity Exposure

    NASA Technical Reports Server (NTRS)

    Crandall, C. G.; Etzel, R. A.

    1999-01-01

    Prolonged exposure to microgravity or its analogues impairs thermoregulation in humans evidenced by higher internal temperatures following the exposure during a thermal challenge. Although the mechanism leading to this response has not been clearly delineated, we identified that prolonged head-down tilt (HDT) markedly impairs thermoregulatory reflex control of skin blood flow, as demonstrated by an increased internal temperature threshold for cutaneous vasodilation, and by a reduced slope of the relationship between the elevation in skin blood flow relative to the elevation in internal temperature. Recently, Fortney et al. identified similar responses in two individuals following 115 days of microgravity exposure. One possible mechanism leading to altered cutaneous vasodilation during a thermal challenge following actual or simulated microgravity exposure may be associated with baroreflex-mediated attenuation in the elevation of skin blood flow. During a heat stress the elevation in skin blood flow is accomplished through a combination of increased cutaneous vascular conductance and cardiac output, both of which result in central venous pressure (CVP) decreasing 2-6 mmHg. Reductions in CVP of this magnitude in normothermia decrease muscle blood flow and skin blood flow presumably through unloading the cardiopulmonary baroreceptors. It is unclear whether the reduction in CVP, and accompanying cardiopulmonary baroreceptor unloading, during passive heating buffers the elevation in skin blood flow. That is, would the elevation in skin blood flow be greater if CVP did not decrease, or decreased to a lesser extent during the heat stress? Conversely, if CVP decreased to a greater extend during a thermal challenge following a perturbation such as prolonged HDT, would the elevation in skin blood flow be attenuated during that thermal challenge? Given that prolonged HDT decreases plasma volume and central venous pressure, such a finding would provide a plausible hypothesis

  18. Cadmium, lead and mercury exposure in non smoking pregnant women

    SciTech Connect

    Hinwood, A.L.; Callan, A.C.; Ramalingam, M.; Boyce, M.; Heyworth, J.; McCafferty, P.; Odland, J.Ø.

    2013-10-15

    Recent literature suggests that exposure to low concentrations of heavy metals may affect both maternal and child health. This study aimed to determine the biological heavy metals concentrations of pregnant women as well as environmental and dietary factors that may influence exposure concentrations. One hundred and seventy three pregnant women were recruited from Western Australia, each providing a sample of blood, first morning void urine, residential soil, dust and drinking water samples. Participants also completed a questionnaire which included a food frequency component. All biological and environmental samples were analysed for heavy metals using ICP-MS. Biological and environmental concentrations of lead and mercury were generally low (Median Pb Drinking Water (DW) 0.04 µg/L; Pb soil <3.0 µg/g; Pb dust 16.5 µg/g; Pb blood 3.67 µg/L; Pb urine 0.55; µg/L Hg DW <0.03; Hg soil <1.0 µg/g; Hg dust <1.0 µg/g; Hg blood 0.46 µg/L; Hg urine <0.40 µg/L). Cadmium concentrations were low in environmental samples (Median CdDW 0.02 µg/L; Cdsoil <0.30 ug/g; Cddust <0.30) but elevated in urine samples (Median 0.55 µg/L, creatinine corrected 0.70 µg/g (range <0.2–7.06 µg/g creatinine) compared with other studies of pregnant women. Predictors of increased biological metals concentrations in regression models for blood cadmium were residing in the Great Southern region of Western Australia and not using iron/folic acid supplements and for urinary cadmium was having lower household annual income. However, these factors explained little of the variation in respective biological metals concentrations. The importance of establishing factors that influence low human exposure concentrations is becoming critical in efforts to reduce exposures and hence the potential for adverse health effects. -- Highlights: • Biological heavy metals concentrations in women in their 3rd trimester of pregnancy. • Exposure assessment including environmental, lifestyle and activity

  19. Lead exposure in indigenous communities of the Amazon basin, Peru.

    PubMed

    Anticona, Cynthia; Bergdahl, Ingvar A; Lundh, Thomas; Alegre, Yuri; Sebastian, Miguel San

    2011-12-01

    Since 2006, three studies have reported elevated levels of lead (Pb) among the indigenous population of the Corrientes river, in the Amazon basin of Peru. Due to the large evidence of environmental pollution related to oil exploitation in the area, this activity has been suggested as the source of exposure. This study aimed to evaluate Pb levels in the population and environment of two communities exposed and one community non-exposed to the oil exploitation activity. Blood lead levels (BLL) were determined by the instrument Leadcare. A comparison with the graphite furnace atomic absorption technique was performed in order to validate the Leadcare results. Environmental samples were analyzed by inductively coupled plasma atomic emission spectroscopy. Among 361 capillary samples, the mean BLL was 9.4 μg/dl. Mean BLL of the communities exposed (n=171, x¯=9.5 μg/dl) and non-exposed (n=190, x¯=9.2 μg/dl) to the oil activity were not significantly different. Pb levels in environmental samples were below the maximum permissible levels. The sources of exposure could not be identified. Elevated levels of Pb in the oil-non-exposed community pointed out at other sources not yet clarified.

  20. Cumulative Head Impact Exposure Predicts Later-Life Depression, Apathy, Executive Dysfunction, and Cognitive Impairment in Former High School and College Football Players.

    PubMed

    Montenigro, Philip H; Alosco, Michael L; Martin, Brett M; Daneshvar, Daniel H; Mez, Jesse; Chaisson, Christine E; Nowinski, Christopher J; Au, Rhoda; McKee, Ann C; Cantu, Robert C; McClean, Michael D; Stern, Robert A; Tripodis, Yorghos

    2017-01-15

    The term "repetitive head impacts" (RHI) refers to the cumulative exposure to concussive and subconcussive events. Although RHI are believed to increase risk for later-life neurological consequences (including chronic traumatic encephalopathy), quantitative analysis of this relationship has not yet been examined because of the lack of validated tools to quantify lifetime RHI exposure. The objectives of this study were: 1) to develop a metric to quantify cumulative RHI exposure from football, which we term the "cumulative head impact index" (CHII); 2) to use the CHII to examine the association between RHI exposure and long-term clinical outcomes; and 3) to evaluate its predictive properties relative to other exposure metrics (i.e., duration of play, age of first exposure, concussion history). Participants included 93 former high school and collegiate football players who completed objective cognitive and self-reported behavioral/mood tests as part of a larger ongoing longitudinal study. Using established cutoff scores, we transformed continuous outcomes into dichotomous variables (normal vs. impaired). The CHII was computed for each participant and derived from a combination of self-reported athletic history (i.e., number of seasons, position[s], levels played), and impact frequencies reported in helmet accelerometer studies. A bivariate probit, instrumental variable model revealed a threshold dose-response relationship between the CHII and risk for later-life cognitive impairment (p < 0.0001), self-reported executive dysfunction (p < 0.0001), depression (p < 0.0001), apathy (p = 0.0161), and behavioral dysregulation (p < 0.0001). Ultimately, the CHII demonstrated greater predictive validity than other individual exposure metrics.

  1. The Yugoslavia Prospective Lead Study: contributions of prenatal and postnatal lead exposure to early intelligence.

    PubMed

    Wasserman, G A; Liu, X; Popovac, D; Factor-Litvak, P; Kline, J; Waternaux, C; LoIacono, N; Graziano, J H

    2000-01-01

    To investigate associations between the timing of lead (Pb) exposure on early intelligence, we examined the results of psychometric evaluations at ages 3, 4, 5, and 7 years, from 442 children whose mothers were recruited during pregnancy from a smelter town and a non-lead-exposed town in Yugoslavia. We compared the relative contribution of prenatal blood lead (BPb) with that of relative increases in BPb in either the early (0-2 years) or the later (from 2 years on) postnatal period to child intelligence measured longitudinally at ages 3 and 4 (McCarthy GCI), 5 (Wechsler Preschool and Primary Scale of Intelligence-Revised, WPPSI-R IQ), and 7 (Wechsler Intelligence Scale for Children-version III, WISC-III IQ), controlling for: Home Observation for Measurement of the Environment (HOME) quality; maternal age, intelligence, education, and ethnicity; and birthweight and gender. Elevations in both prenatal and postnatal BPb were associated with small decrements in young children's intelligence.

  2. Developmental lead exposure causes startle response deficits in zebrafish.

    PubMed

    Rice, Clinton; Ghorai, Jugal K; Zalewski, Kathryn; Weber, Daniel N

    2011-10-01

    Lead (Pb(2+)) exposure continues to be an important concern for fish populations. Research is required to assess the long-term behavioral effects of low-level concentrations of Pb(2+) and the physiological mechanisms that control those behaviors. Newly fertilized zebrafish embryos (<2h post fertilization; hpf) were exposed to one of three concentrations of lead (as PbCl(2)): 0, 10, or 30 nM until 24 hpf. (1) Response to a mechanosensory stimulus: Individual larvae (168 hpf) were tested for response to a directional, mechanical stimulus. The tap frequency was adjusted to either 1 or 4 taps/s. Startle response was recorded at 1000 fps. Larvae responded in a concentration-dependent pattern for latency to reaction, maximum turn velocity, time to reach V(max) and escape time. With increasing exposure concentrations, a larger number of larvae failed to respond to even the initial tap and, for those that did respond, ceased responding earlier than control larvae. These differences were more pronounced at a frequency of 4 taps/s. (2) Response to a visual stimulus: Fish, exposed as embryos (2-24 hpf) to Pb(2+) (0-10 μM) were tested as adults under low light conditions (≈ 60 μW/m(2)) for visual responses to a rotating black bar. Visual responses were significantly degraded at Pb(2+) concentrations of 30 nM. These data suggest that zebrafish are viable models for short- and long-term sensorimotor deficits induced by acute, low-level developmental Pb(2+) exposures.

  3. Relative contribution of lead from anthropogenic sources to the total human lead exposure in the United States. Final report

    SciTech Connect

    Elias, R.W.

    1986-08-01

    The paper evaluates human exposure to lead at a baseline level for persons living in non-urban communities away from stationary or mobile sources of lead, eating typical diets, and engaging in no lead-related occupational or avocational activities. Relative contributions of atmospheric and metallic lead are evaluated for each exposure pathway. For this baseline situation, perhaps 40 to 55% of the total human exposure to lead is of atmospheric origin. Beyond the baseline level, additional exposure factors can be determined for other environments (e.g. urban, occupational, smelter communities) and for certain habits and activities (e.g., pica, smoking, drinking, and various hobbies), with variations for age, sex, or socioeconomic status. Although quantification of these factors is uncertain, they provide guidelines in determining relative exposures under differing environmental conditions. The added exposure factors can also be partitioned into atmospheric, metallic, and pigment lead.

  4. Risk assessment of the cumulative acute exposure of Hungarian population to organophosphorus pesticide residues with regard to consumers of plant based foods.

    PubMed

    Zentai, Andrea; Szabó, István J; Kerekes, Kata; Ambrus, Árpád

    2016-03-01

    Based on the Hungarian pesticide residues monitoring data of the last five years and the consumption data collected within a 3-day dietary record survey in 2009 (more than 2 million pesticide residue results and almost 5000, 0-101-year-old consumers 3 non-consecutive-day personal fruit and vegetable consumption data), the cumulative acute exposure of organophosphorus pesticide residues was evaluated. The relative potency factor approach was applied, with acephate chosen as index compound. According to our conservative calculation method, applying the measured residues only, the 99.95% of the 99th percentiles of calculated daily intakes was at or below 87 μg/kgbwday, indicating that the cumulative acute exposure of the whole Hungarian population (including all age classes) to organophosphorus compounds was not a health concern.

  5. Development of a Prototype Optical Hydrogen Gas Sensor Using a Getter-Doped Polymer Transducer for Monitoring Cumulative Exposure: Preliminary Results

    SciTech Connect

    Small IV, W; Maitland, D J; Wilson, T S; Bearinger, J P; Letts, S A; Trebes, J E

    2008-06-05

    A novel prototype optical sensor for monitoring cumulative hydrogen gas exposure was fabricated and evaluated. Chemical-to-optical transduction was accomplished by detecting the intensity of 670 nm laser light transmitted through a hydrogen getter-doped polymer film mounted at the end of an optical fiber; the transmittance of the composite film increased with uptake of hydrogen by the embedded getter. The composite film consisted of the hydrogen getter 1,4-bis(phenylethynyl)benzene, also known as DEB, with carbon-supported palladium catalyst embedded in silicone elastomer. Because the change in transmittance was irreversible and occurred continuously as the getter captured hydrogen, the sensor behaved like a dosimeter, providing a unique indication of the cumulative gas exposure.

  6. Feather lead concentrations and (207)Pb/(206)Pb ratios reveal lead exposure history of California Condors (Gymnogyps californianus).

    PubMed

    Finkelstein, M E; George, D; Scherbinski, S; Gwiazda, R; Johnson, M; Burnett, J; Brandt, J; Lawrey, S; Pessier, A P; Clark, M; Wynne, J; Grantham, J; Smith, D R

    2010-04-01

    Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only approximately 10% of a bird's annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird's lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2-4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant of population health, our findings should increase the understanding of population-level effects from lead poisoning in condors; this information may also be helpful for other avian species potentially impacted by lead poisoning.

  7. Comparison of blood and tissue lead concentrations from cattle with known lead exposure.

    PubMed

    Bischoff, Karyn; Hillebrandt, Joseph; Erb, Hollis N; Thompson, Belinda; Johns, Sonia

    2016-10-01

    Blood lead (Pb) is used to diagnose Pb poisoning and exposure in cattle, but there are limited data comparing circulating Pb with concentrations in beef from the same cattle. This study determines whether there is a correlation between blood Pb and tissue Pb concentrations in accidentally exposed cattle. Pb analyses were carried out on ante-mortem blood and post-mortem tissues (including, if available, brain, liver, skeletal muscle, bone, gastrointestinal contents and kidney, and also foetal tissues from one cow) collected from 13 cattle known to have accidental Pb exposure and from three control cows with no known exposure. Variables from cattle were analysed statistically using a Shapiro-Wilk normality test and non-parametric descriptive and association statistics. Blood Pb from exposed cattle rank-correlated with liver, bone and kidney Pb concentrations, but not with the Pb concentrations of brain, skeletal muscle or gastrointestinal contents. The lowest blood Pb concentration associated with a detectable skeletal muscle Pb concentration (> 0.1 mg kg(-)(1) dry matter) was 4.57 μg dl(-1). Based on these findings, we recommend that cattle with blood Pb > 2.5 μg dl(-1) be withheld from slaughter and that liver, bone and kidney from all cattle with known Pb exposure be withheld from the human food chain.

  8. The Influence of Lead Exposure and Toxicity to Children's Neurological Development and School Performance.

    ERIC Educational Resources Information Center

    Kimball, Sarah L.

    This report discusses the effects of lead exposure and toxicity on children's cognitive development and school performance and addresses the role of schools in prevention of lead poisoning. Sources of lead exposure include mining, smelting and refining activities, lead paint, leaded gasoline, and industrial emissions. The results of lead poisoning…

  9. Consumption of fruits and vegetables and probabilistic assessment of the cumulative acute exposure to organophosphorus and carbamate pesticides of schoolchildren in Slovenia.

    PubMed

    Blaznik, Urška; Yngve, Agneta; Eržen, Ivan; Hlastan Ribič, Cirila

    2016-02-01

    Adequate consumption of fruits and vegetables is a part of recommendations for a healthy diet. The aim of the present study was to assess acute cumulative dietary exposure to organophosphorus and carbamate pesticides via fruit and vegetable consumption by the population of schoolchildren aged 11-12 years and the level of risk for their health. Cumulative probabilistic risk assessment methodology with the index compound approach was applied. Slovenia, primary schools. Schoolchildren (n 1145) from thirty-one primary schools in Slovenia. Children were part of the PRO GREENS study 2009/10 which assessed 11-year-olds' consumption of fruit and vegetables in ten European countries. The cumulative acute exposure amounted to 8.3 (95% CI 7.7, 10.6) % of the acute reference dose (ARfD) for acephate as index compound (100 µg/kg body weight per d) at the 99.9th percentile for daily intake and to 4.5 (95% CI 3.5, 4.7) % of the ARfD at the 99.9th percentile for intakes during school time and at lunch. Apples, bananas, oranges and lettuce contributed most to the total acute pesticides intake. The estimations showed that acute dietary exposure to organophosphorus and carbamate pesticides is not a health concern for schoolchildren with the assessed dietary patterns of fruit and vegetable consumption.

  10. Air lead exposures and blood lead levels within a large automobile manufacturing workforce, 1980-1985.

    PubMed

    Kononen, D W; Kintner, H J; Bivol, K R

    1989-01-01

    Recent (1980-1985) trends in air lead (PbA) exposures and blood lead (PbB) levels experienced by approximately 10,000 workers employed in various stages of the automobile manufacturing process (i.e., auto assembly, lead-acid battery manufacture, foundry work, and "other" manufacturing-related operations) are described. Between 1980-1985, the mean PbB levels of assembly, battery, foundry, and "other" workers decreased by 28, 24, 3, and 27%, respectively, to 16.6, 23.6, 15.9, and 11.8 micrograms Pb/dl. Workers in the following job categories experienced the highest annual mean PbB levels: paste machine operators (battery plants), solder-grinders (assembly plants), and crane operators (foundries). During the same period, median 8-h Time Weighted Average PbA exposures (micrograms Pb/m3) in assembly plants, battery plants, and foundries decreased by 10, 12, and 20%, respectively, to 8.1, 13.6, and 10.9 micrograms/m3.

  11. Exposure to phthalates in 5-6 years old primary school starters in Germany--a human biomonitoring study and a cumulative risk assessment.

    PubMed

    Koch, Holger M; Wittassek, Matthias; Brüning, Thomas; Angerer, Jürgen; Heudorf, Ursel

    2011-06-01

    We determined the internal exposure of 111 German primary school starters by analyzing urinary metabolites of six phthalates: butyl benzyl phthalate (BBzP), di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di (2-ethylhexyl) phthalate (DEHP), di-iso-nonyl phthalate (DiNP) and di-iso-decylphthalate (DiDP). From the urinary metabolite levels, we calculated daily intakes and related these values to Tolerable Daily Intake (TDI) values. By introducing the concept of a relative cumulative Tolerable Daily Intake (TDI(cum)) value, we tried to account for the cumulative exposure to several of the above-mentioned phthalates. The TDI(cum) was derived as follows: the daily intake (DI) calculated from the metabolite level was divided by the TDI for each phthalate; this ratio was multiplied by 100% indicating the TDI percentage for which the DI accounted. Finally the % TDIs of the different phthalates were totalled to get the TDI(cum). A TDI(cum) above 100% is a potential cause for concern. We confirmed the ubiquitous exposure of the children to all phthalates investigated. Exposures were within range of levels previously reported for GerES, albeit slightly lower. Regarding daily intakes, two children exceeded the TDI for DnBP, whereas one child closely approached the TDI for DEHP. 24% of the children exceeded the TDI(cum) for the three most critical phthalates: DEHP, DnBP and DiBP. Furthermore, 54% of the children had total exposures that used up more than 50% the TDI(cum). Therefore, the overall exposure to a number of phthalates, and the knowledge that these phthalates (and other anti-androgens) act in a dose-additive manner, urgently warrants a cumulative risk assessment approach.

  12. Comparative Risks of Cancer from Drywall Finishing Based on Stochastic Modeling of Cumulative Exposures to Respirable Dusts and Chrysotile Asbestos Fibers.

    PubMed

    Boelter, Fred W; Xia, Yulin; Dell, Linda

    2015-05-01

    Sanding joint compounds is a dusty activity and exposures are not well characterized. Until the mid 1970s, asbestos-containing joint compounds were used by some people such that sanding could emit dust and asbestos fibers. We estimated the distribution of 8-h TWA concentrations and cumulative exposures to respirable dusts and chrysotile asbestos fibers for four worker groups: (1) drywall specialists, (2) generalists, (3) tradespersons who are bystanders to drywall finishing, and (4) do-it-yourselfers (DIYers). Data collected through a survey of experienced contractors, direct field observations, and literature were used to develop prototypical exposure scenarios for each worker group. To these exposure scenarios, we applied a previously developed semi-empirical mathematical model that predicts area as well as personal breathing zone respirable dust concentrations. An empirical factor was used to estimate chrysotile fiber concentrations from respirable dust concentrations. On a task basis, we found mean 8-h TWA concentrations of respirable dust and chrysotile fibers are numerically highest for specialists, followed by generalists, DIYers, and bystander tradespersons; these concentrations are estimated to be in excess of the respective current but not historical Threshold Limit Values. Due to differences in frequency of activities, annual cumulative exposures are highest for specialists, followed by generalists, bystander tradespersons, and DIYers. Cumulative exposure estimates for chrysotile fibers from drywall finishing are expected to result in few, if any, mesothelioma or excess lung cancer deaths according to recently published risk assessments. Given the dustiness of drywall finishing, we recommend diligence in the use of readily available source controls.

  13. Reproductive hazards of lead exposure among urban Egyptian men.

    PubMed

    El-Zohairy, E A; Youssef, A F; Abul-Nasr, S M; Fahmy, I M; Salem, D; Kahil, A K; Madkour, M K

    1996-01-01

    Fifty-five urban Egyptian males, aged 20-40, were assigned to two main groups to study the effects of their exposure to lead (Pb). Group I, infertile men (INF, n = 30), was divided into environmentally exposed (INF-E, n = 15) and environmentally and occupationally exposed (INF-EO, n = 15). A matching group (II) of fertile men (F, n = 25) was divided into fertile, environmentally exposed (F-E, n = 10), which was the control group, and fertile, environmentally and occupationally exposed (F-EO, n = 15). Semen parameters (i.e., count, morphology, motility, and volume), blood and semen Pb levels, and reproductive hormonal indices (i.e., serum testosterone, FSH, and LH) were measured in all subjects. Lead levels were always higher in blood than semen. Semen lead levels were significantly higher in all groups vs. the control (F-E) group. While no changes were observed in testosterone levels across groups, variable effects on LH and FSH levels were observed. Infertile-EO subjects showed a definite pattern of impaired semen parameters in comparison with infertile-E. No abnormalities were detected in hematologic, hepatic or renal function.

  14. In-vivo measurements of Pb-210 to determine cumulative exposure to radon daughters: A pilot study. Final report, 1 March, 1990--May 31, 1991

    SciTech Connect

    Laurer, G.R.; Cohen, N.; Stark, A.; Ju, C.

    1991-05-01

    The objective of this study is to demonstrate the feasibility of estimating cumulative exposure of individuals to low concentrations of radon by measuring the amount of Pb-A-10 in their skeletons. This report presents progress to date establishing the validity of an vivo technique to measure skeletal burdens of Pb-210, accumulated from exposure to radon and radon progeny. With the skeletal content of Pb--210 and a model for Pb metabolism, cumulative exposure to radon and its short-lived daughters (radon/daughters) may be calculated for use in deriving a dose-response relationship between lung cancer and exposure to radon/daughters. Data are presented for 29 subjects exposed to ``above-average`` radon concentrations in their homes, showing the correlation between measured Pb--210 burdens, and measured pCi/l and WLM exposure estimates. Their results are compared to measurements of a population of 24 subject`s presumed exposed to average concentrations. Measurements of a Pennsylvania family exposed for a year in a home with an extremely high radon content are also presented. Update of results of an ongoing study of the biological half-time of Pb--210 in man involving measurements, of a retired radiation worker with a 40 year old skeletal burden of Pb-210.

  15. A comparison of elementary schoolchildren's exposure to arsenic and lead.

    PubMed

    Chiang, Wan-Fu; Yang, Hao-Jan; Lung, Shih-Chun Candice; Huang, Shuai; Chiu, Chih-Yuan; Liu, I-Ling; Tsai, Ching-Ling; Kuo, Chung-Yih

    2008-01-01

    One hundred fifty seven fifth-grade students (aged 10-12 years) from three elementary schools in three different towns in Taichung County, Taiwan were chosen as study subjects for the present arsenic and lead exposure study. The three towns--Longgang, Shalach, and Shuntain--are known to be highly, moderately, and lightly (control) polluted by As and Pb, respectively. Spot morning urine samples of students were collected and analyzed for arsenic and lead. The levels of As in the urine of Longgang schoolchildren showed the highest value among the three schools, while those of the control group (Shuntain) had the lowest values. In addition, the levels of Pb in the urine of the schoolchildren in Shuntain were significantly lower than those in Longgang and Shalach, while the levels of Pb in the urine of the schoolchildren in Longgang and Shalach showed no significant difference. Results of daily intake of metals from the different exposure pathways (i.e., ingestion from drinking water, household dust and food, and inhalation from airborne particles) showed that the Longgang area had the highest daily intake of As and Pb among the three areas, while the lowest daily intake of As and Pb occurred in the control area (Shuntain). A significant correlation between the doses of daily intake and urinary concentrations of As (p = 0.002) and Pb (p = 0.020) was observed. This correlation suggests that the increase of unit dose of the daily intake for As resulted in an increase of 0.953 microg g(-1) creatinine of As, whereas the increase of unit dose of the daily intake for Pb led to an increase of 0.053 microg g(-1) creatinine of Pb. These data indicate that the level of As in urine increased about 18 times higher than that of Pb for the same amount of increase in daily intake.

  16. Feather lead concentrations and207Pb/206Pb ratios reveal lead exposure history of California condors (Gymnogyps californianus)

    USGS Publications Warehouse

    Finkelstein, M.E.; George, D.; Scherbinski, S.; Gwiazda, R.; Johnson, M.; Burnett, J.; Brandt, J.; Lawrey, S.; Pessier, Allan P.; Clark, M.; Wynne, J.; Grantham, And J.; Smith, D.R.

    2010-01-01

    Lead poisoning is a primary factor impeding the survival and recovery of the critically endangered California Condor (Gymnogyps californianus). However, the frequency and magnitude of lead exposure in condors is not well-known in part because most blood lead monitoring occurs biannually, and biannual blood samples capture only ???10% of a bird's annual exposure history. We investigated the use of growing feathers from free-flying condors in California to establish a bird's lead exposure history. We show that lead concentration and stable lead isotopic composition analyses of sequential feather sections and concurrently collected blood samples provided a comprehensive history of lead exposure over the 2-4 month period of feather growth. Feather analyses identified exposure events not evident from blood monitoring efforts, and by fitting an empirically derived timeline to actively growing feathers, we were able to estimate the time frame for specific lead exposure events. Our results demonstrate the utility of using sequentially sampled feathers to reconstruct lead exposure history. Since exposure risk in individuals is one determinant ?? 2010 American Chemical Society.

  17. Influence of abatement of lead exposure in Croatia on blood lead and ALAD activity.

    PubMed

    Zorana, Kljaković-Gašpić; Alica, Pizent; Jasna, Jurasović

    2016-01-01

    We evaluated the effect of lead (Pb) abatement measures in Croatia on blood lead (BPb) concentrations, and delta-aminolevulinic acid dehydratase (ALAD) activity in blood, as a sensitive indicator of early Pb effect. Data on BPb and ALAD activity were obtained from 829 Croatian men (19-64 years of age), with no known occupational exposure to metals. Data obtained in 2008-2009, after the ban of leaded gasoline in Croatia in 2006, were compared with similar data collected in 1981 and 1989, when the concentration of Pb in gasoline was 0.6 g/L. Our results showed a highly significant (p < 0.001) decrease in median BPb from 114.5 (range, 46.0-275.0) μg/L in 1981/1989 to 30.3 (range, 3.2-140.8) μg/L in 2008-2009 and an increase in median ALAD activity from 49.8 (range, 24.9-79.4) EU in 1981/1989 to 60.9 (range, 35.8-84.0) EU in 2008-2009. Individual factors influencing BPb values were, in the order of decreasing importance, Pb in ambient air (APb), alcohol consumption, age, and smoking. Increased ALAD activity was significantly associated with the decrease of APb, alcohol consumption, and smoking. These results show that lead abatement measures had a positive impact on both BPb concentrations (73.5% decrease) and the activity of ALAD (22.1% increase) in general population. Our results contribute to growing evidence that ALAD activity may be used as one of the earliest and sensitive diagnostic biomarkers of low-level Pb exposure.

  18. Cadmium and lead exposure and risk of cataract surgery in U.S. adults.

    PubMed

    Wang, Weiye; Schaumberg, Debra A; Park, Sung Kyun

    2016-11-01

    Cataract is a major cause of visual dysfunction and the leading cause of blindness. Elevated levels of cadmium and lead have been found in the lenses of cataract patients, suggesting these metals may play a role in cataract risk. This study aimed to examine the associations of blood lead, blood cadmium and urinary cadmium with cataract risk. We identified 9763 individuals aged 50 years and older with blood lead and cadmium levels, and a randomly selected subgroup of 3175 individuals with available urinary cadmium levels, from the National Health and Nutrition Examination Surveys (NHANES) from 1999 to 2008 (mean age=63years). Participants were considered to have cataract if they self-reported prior cataract surgery in NHANES's vision examination. Odds ratios (ORs) and 95% confidence intervals (CIs) were computed using survey logistic regression models. We identified 1737 cataract surgery cases (the weighted prevalence=14.1%). With adjustment for age, race/ethnicity, gender, education, diabetes mellitus, body mass index, cigarette smoking (serum cotinine and pack-years) and urine hydration, every 2-fold increase in urinary cadmium was associated with a 23% higher risk of cataract surgery (OR=1.23, 95% CI: 1.04, 1.46, p=0.021). We found no associations of cataract surgery with blood cadmium (OR=0.97, 95% CI: 0.89, 1.07) and blood lead (OR=0.97, 95% CI: 0.88, 1.06). Mediation analysis showed that for the smoking-cadmium-cataract pathway, the ratio of smoking's indirect effect to the total effect through cadmium was more than 50%. These results suggest that cumulative cadmium exposure may be an important under-recognized risk factor for cataract. However, these findings should be interpreted with a caution because of inconsistent results between urinary cadmium and blood cadmium.

  19. Chronic cumulative risk assessment of the exposure to organophosphorus, carbamate and pyrethroid and pyrethrin pesticides through fruit and vegetables consumption in the region of Valencia (Spain).

    PubMed

    Quijano, Leyre; Yusà, Vicent; Font, Guillermina; Pardo, Olga

    2016-03-01

    In the present study, the chronic cumulative exposure to organophosphorus (OPs), carbamates (CBs) and pyrethroid and pyrethrin (PPs) pesticides in the region of Valencia through fruit and vegetables consumption is presented. A total of 752 samples and 84 pesticides were studied of which, 52 were OPs, 23 CBs and 9 PPs. Residue data were derived from the Valencia Region monitoring program 2007-2011 and food consumption levels from a questionnaire-based dietary survey conducted in 2010 in the same area. The relative potency factor (RPFs) approach was used to estimate chronic cumulative dietary exposure to OPs, CBs and PPs using acephate, oxamyl and deltamethrin as index compounds, respectively. The exposure was estimated using a deterministic approach and two scenarios were assumed for left-censored results: the lower-bound (LB) scenario, in which unquantified results (below the limit of quantification (LOQ)) were set to zero and the upper-bound (UB) scenario, in which unquantified results were set to the LOQ. Results demonstrate that the chronic exposure of the young (<16 years) and adult (≥ 16 years) population to pesticides through fruits and vegetables is under control (even at high or frequent consumption of fruits and vegetables), for the three groups of pesticides. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Reducing lead in air and preventing childhood exposure near lead smelters: learning from the U.S. experience.

    PubMed

    Sullivan, Marianne

    2015-05-01

    Childhood lead exposure and poisoning near primary lead smelters continues in developed and developing countries. In the United States, the problem of lead poisoning in children caused by smelter emissions was first documented in the early 1970s. In 1978, Environmental Protection Agency set National Ambient Air Quality Standards for lead. Attainment of this lead standard in areas near operating lead smelters took twenty to thirty years. Childhood lead exposure and poisoning continued to occur after the lead National Ambient Air Quality Standards were set and before compliance was achieved. This article analyzes and discusses the factors that led to the eventual achievement of the 1978 lead National Ambient Air Quality Standards near primary smelters and the reduction of children's blood lead levels in surrounding communities. Factors such as federal and state regulation, monitoring of emissions, public health activities such as blood lead surveillance and health education, relocation of children, environmental group and community advocacy, and litigation all played a role.

  1. Environmental Lead Exposure and Otoacoustic Emissions in Andean Children

    PubMed Central

    Buchanan, Leo H.; Counter, S. Allen; Ortega, Fernando

    2012-01-01

    Studies relating sensory hearing impairment to lead (Pb) exposure in children have presented inconsistent results. The objective of this study was to measure distortion product otoacoustic emissions (DPOAE), sounds emanating from the outer hair cells of the inner ear, in Pb-exposed children to determine the effects of Pb poisoning on the inner ear. DPOAE were recorded for 9 f2 frequencies from 1187 to 7625 Hz on 102 ears of 53 Pb-exposed children (aged 6–16 years) residing in Pb-contaminated environments in the Andes Mountains of Ecuador where Pb-glazing of ceramics is the primary livelihood. Blood lead (PbB) levels ranged from 4.2 to 94.3 µg/dl (mean: 37.7; SD: 25.7; median: 36.4). The median PbB level was significantly higher than the CDC and WHO’s 10 µg/dl action level. Spearman rho correlation analyses of the relation between PbB level and DPOAE amplitude, and between PbB level and DPOAE signal-to-noise ratio revealed no significant associations at any of the f2 frequencies tested. In addition, no significant correlation (Spearman rho) between PbB level and hearing sensitivity for 6 pure-tone test frequencies from 1000–8000 Hz was found. Although the study group was found to have abnormally elevated PbB levels, in contrast to some earlier reports, the results of the current study showed no consistent Pb-induced sensory effects on the cochlea of Pb-intoxicated children. PMID:21830857

  2. Environmental lead exposure and otoacoustic emissions in Andean children.

    PubMed

    Buchanan, Leo H; Counter, S Allen; Ortega, Fernando

    2011-01-01

    Studies relating sensory hearing impairment to lead (Pb) exposure in children have presented inconsistent results. The objective of this study was to measure distortion product otoacoustic emissions (DPOAE), sounds emanating from the outer hair cells of the inner ear, in Pb-exposed children to determine the effects of Pb poisoning on the inner ear. DPOAE were recorded for 9 f(2) frequencies from 1187 to 7625 Hz on 102 ears of 53 Pb-exposed children (aged 6-16 yr) residing in Pb-contaminated environments in the Andes Mountains of Ecuador where Pb glazing of ceramics is the primary livelihood. Blood lead (PbB) levels ranged from 4.2 to 94.3 μg/dl (mean: 37.7; SD: 25.7; median: 36.4). The median PbB level was markedly higher than the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) 10-μg/dl action level. Spearman rho correlation analyses of the relation between PbB level and DPOAE amplitude and between PbB level and DPOAE signal-to-noise ratio revealed no significant associations at any of the f(2) frequencies tested. In addition, no significant correlation (Spearman rho) between PbB level and hearing sensitivity for 6 pure-tone test frequencies from 1000 to 8000 Hz was found. Although the study group was found to have abnormally elevated PbB levels, in contrast to some earlier reports, the results of the current study showed no consistent Pb-induced sensory effects on the cochlea of Pb-intoxicated children.

  3. Childhood lead exposure in an industrial town in China: coupling stable isotope ratios with bioaccessible lead.

    PubMed

    Li, Hong-Bo; Chen, Kai; Juhasz, Albert L; Huang, Lei; Ma, Lena Q

    2015-04-21

    Fingerprinting based on stable isotopes of lead (Pb) in blood and environmental media helps to identify Pb exposure pathways in children. However, previous studies used stable isotopes of total Pb in media. In this study, a wire rope production town in China (Zhuhang) was selected for investigating the effectiveness of using isotope ratios in bioaccessible Pb to identify childhood Pb exposure pathways. Blood Pb levels of 115 children in Zhuhang were 1.7-20.4 μg dL(-1), averaging 6.1 ± 3.2 μg dL(-1) (mean ± standard deviation), and were ∼1.6 times the national average in China (3.9 ± 1.8 μg dL(-1)). Among different environmental media (housedust, soil, PM10, vegetables, rice, and drinking water), housedust (695 ± 495 mg kg(-1)) and vegetables [0.36 ± 0.40 mg (kg of fresh weight)(-1)] contained elevated Pb concentrations. The isotope ratios ((207)Pb/(206)Pb and (208)Pb/(206)Pb) of total Pb were the highest in housedust (0.8587 ± 0.0039 and 2.1049 ± 0.0087) but lower than blood Pb ratios (0.8634 ± 0.0027 and 2.1244 ± 0.0061). When using bioaccessible Pb in housedust (0.8639 ± 0.0018 and 2.1171 ± 0.0036), the isotope ratios overlapped with blood Pb ratios, suggesting that incidental ingestion of housedust was the predominant contributor to children's blood Pb. Coupling the stable isotope technique with bioaccessible Pb is more reliable for identifying Pb exposure pathways than total Pb determinations.

  4. Levels and source apportionment of children's lead exposure: could urinary lead be used to identify the levels and sources of children's lead pollution?

    PubMed

    Cao, Suzhen; Duan, Xiaoli; Zhao, Xiuge; Wang, Beibei; Ma, Jin; Fan, Delong; Sun, Chengye; He, Bin; Wei, Fusheng; Jiang, Guibin

    2015-04-01

    As a highly toxic heavy metal, the pollution and exposure risks of lead are of widespread concern for human health. However, the collection of blood samples for use as an indicator of lead pollution is not always feasible in most cohort or longitudinal studies, especially those involving children health. To evaluate the potential use of urinary lead as an indicator of exposure levels and source apportionment, accompanying with environmental media samples, lead concentrations and isotopic measurements (expressed as (207)Pb/(206)Pb, (208)Pb/(206)Pb and (204)Pb/(206)Pb) were investigated and compared between blood and urine from children living in the vicinities of a typical coking plant and lead-acid battery factory. The results showed urinary lead might not be a preferable proxy for estimating blood lead levels. Fortunately, urinary lead isotopic measurements could be used as an alternative for identifying the sources of children's lead exposure, which coincided well with the blood lead isotope ratio analysis.

  5. Impact of the California Lead Ammunition Ban on Reducing Lead Exposure in Golden Eagles and Turkey Vultures

    PubMed Central

    Kelly, Terra R.; Bloom, Peter H.; Torres, Steve G.; Hernandez, Yvette Z.; Poppenga, Robert H.; Boyce, Walter M.; Johnson, Christine K.

    2011-01-01

    Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites. PMID:21494329

  6. Impact of the California lead ammunition ban on reducing lead exposure in golden eagles and turkey vultures.

    PubMed

    Kelly, Terra R; Bloom, Peter H; Torres, Steve G; Hernandez, Yvette Z; Poppenga, Robert H; Boyce, Walter M; Johnson, Christine K

    2011-04-06

    Predatory and scavenging birds may be exposed to high levels of lead when they ingest shot or bullet fragments embedded in the tissues of animals injured or killed with lead ammunition. Lead poisoning was a contributing factor in the decline of the endangered California condor population in the 1980s, and remains one of the primary factors threatening species recovery. In response to this threat, a ban on the use of lead ammunition for most hunting activities in the range of the condor in California was implemented in 2008. Monitoring of lead exposure in predatory and scavenging birds is essential for assessing the effectiveness of the lead ammunition ban in reducing lead exposure in these species. In this study, we assessed the effectiveness of the regulation in decreasing blood lead concentration in two avian sentinels, golden eagles and turkey vultures, within the condor range in California. We compared blood lead concentration in golden eagles and turkey vultures prior to the lead ammunition ban and one year following implementation of the ban. Lead exposure in both golden eagles and turkey vultures declined significantly post-ban. Our findings provide evidence that hunter compliance with lead ammunition regulations was sufficient to reduce lead exposure in predatory and scavenging birds at our study sites.

  7. Lead exposure and growth in the early preschool child: A follow-up report from the Cincinnati Lead Study

    SciTech Connect

    Shukla, R.; Dietrich, K.N.; Bornschein, R.L.; Berger, O.; Hammond, P.B. )

    1991-11-01

    This report is a follow-up of an earlier study of the effects of low to moderate prenatal and postnatal lead exposure on children's growth in stature. Two hundred thirty-five subjects were assessed every 3 months for lead exposure (blood lead level) and stature (recumbent length) up to 33 months of age. Fetal lead exposure was indexed by maternal blood lead level during pregnancy. The adverse effects of lead on growth during the first year of life were reported previously. This analysis covers essentially the second and third years of life. The results indicate that mean blood lead level during this period was negatively associated with attained height at 33 months of age (P = .002). This association was, however, evidenced only among those children who had mean blood lead levels greater than the cohort median (greater than or equal to 10.77 micrograms/dL) during the 3- to 15-month interval. The results also suggest that the effect of lead exposure (both in utero as well as during the first year of life) are transient provided that subsequent exposure to lead is not excessive. It appears that maintaining an average blood lead level of 25 micrograms/dL or more during the second and third year of life was detrimental to the child's attained stature at 33 months of age. Approximately 15% of this cohort experienced these levels of lead exposure. Continued follow-up of this cohort will reveal whether these lead-related deficits persist and whether they continue to be dependent on the level of exposure in an earlier period.

  8. A new approach for quantifying cumulative, anthropogenic, atmospheric lead deposition using peat cores from bogs: Pb in eight Swiss peat bog profiles.

    PubMed

    Shotyk, W; Blaser, P; Grünig, A; Cheburkin, A K

    2000-04-17

    Peat cores taken from eight Swiss peatlands were used to calculate inventories of anthropogenic Pb using either Sc or Zr to quantify Pb derived from rock weathering. The shapes of the Pb/Sc and Pb/Zr profiles suggest that Pb was supplied exclusively by atmospheric deposition at all sites. At one of the sites (Etang de la Gruère), anthropogenic Pb was calculated using both Sc and Zr as the conservative reference element. Lithogenic Pb determined using Sc was twice that obtained using Zr, possibly because Zr resides only in zircons which are dense compared to pyroxene and amphibole which are the main Sc-bearing phases in the earth's crust. However, the inventory of 'natural' Pb (supplied almost entirely by soil dust) is dwarfed by the anthropogenic inventory such that anthropogenic Pb calculated using Sc and Zr agree to within 5%. The total amount of anthropogenic Pb accumulated in the bogs was calculated by simply adding the mass of anthropogenic Pb for each peat slice over the length of each core. Cumulative, anthropogenic Pb calculated in this way ranged from 1.0 to 9.7 g/m2 and showed pronounced regional differences: the site south of the Alps (Gola di Lago in Canton Ticino) with direct exposure to the heavily industrialized region of northern Italy received nearly 10 times more anthropogenic Pb as the sites in more remote alpine regions (Schöpfenwaldmoor in Canton Berne, and Mauntschas in Canton Grisons). The approach used here to calculate cumulative, anthropogenic, atmospheric Pb (CAAPb) is simple and robust, independent of the chronology of Pb deposition, and makes no assumptions about the immobility of Pb within the peat profile. Given the worldwide distribution of peat bogs, it should be possible to undertake continental and global inventories of atmospheric metal deposition, for both the natural and anthropogenic components of most trace metals of environmental interest.

  9. Lead exposure: Public and Occupational Health Hazards. (Latest citations from Pollution Abstracts). Published Search

    SciTech Connect

    Not Available

    1992-06-01

    The bibliography contains citations concerning the effects of chronic lead exposure in humans and animals. The citations explore lead exposure resulting from occupational hazards, automobile emissions, and air pollution. Lead absorption in children is discussed. The clinical features of lead toxicity are noted, and biochemical assays for the quantification of blood and tissue lead levels are discussed. D-aminolevulenic acid dehydratase and its relation to blood lead levels are cited. (Contains 250 citations and includes a subject term index and title list.)

  10. Childhood Exposure to Lead: A Common Cause of School Failure.

    ERIC Educational Resources Information Center

    Needleman, Herbert L.

    1992-01-01

    According to the U.S. Public Health Service, lead poisoning remains the most common and societally devastating environmental disease of young children. About 16 percent all American children have blood lead levels in the neurotoxic range. Being poor dramatically increases this risk. The lead industry has long camouflaged lead's toxicity.…

  11. Lead exposure in radiator repair workers: a survey of Washington State radiator repair shops and review of occupational lead exposure registry data.

    PubMed

    Whittaker, Stephen G

    2003-07-01

    Radiator repair workers in Washington State have the greatest number of very elevated (> or =60 microg/dL) blood lead levels of any other worker population. The goals of this study were to determine the number of radiator repair workers potentially exposed to lead; estimate the extent of blood lead data underreporting to the Occupational Lead Exposure Registry; describe current safety and health practices in radiator repair shops; and determine appropriate intervention strategies to reduce exposure and increase employer and worker awareness. Lead exposure in Washington State's radiator repair workers was assessed by reviewing Registry data and conducting a statewide survey of radiator repair businesses. This study revealed that a total of 226 workers in Washington State (including owner-operators and all employees) conduct repair activities that could potentially result in excessive exposures to lead. Approximately 26% of radiator repair workers with elevated blood lead levels (> or =25 microg/dL) were determined to report to Washington State's Registry. This study also revealed a lack of awareness of lead's health effects, appropriate industrial hygiene controls, and the requirements of the Lead Standard. Survey respondents requested information on a variety of workplace health and safety issues and waste management; 80% requested a confidential, free-of-charge consultation. Combining data derived from an occupational health surveillance system and a statewide mail survey proved effective at characterizing lead exposures and directing public health intervention in Washington State.

  12. Cumulative Effects of Prenatal Substance Exposure and Early Adversity on Foster Children's HPA-Axis Reactivity during a Psychosocial Stressor

    ERIC Educational Resources Information Center

    Fisher, Philip A.; Kim, Hyoun K.; Bruce, Jacqueline; Pears, Katherine C.

    2012-01-01

    Dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis stress response has been reported among individuals with prenatal substance exposure and those with early adversity exposure. However, few researchers have examined the combined effects of these risk factors. Patterns of HPA reactivity among maltreated foster children with and without…

  13. Cumulative Effects of Prenatal Substance Exposure and Early Adversity on Foster Children's HPA-Axis Reactivity during a Psychosocial Stressor

    ERIC Educational Resources Information Center

    Fisher, Philip A.; Kim, Hyoun K.; Bruce, Jacqueline; Pears, Katherine C.

    2012-01-01

    Dysregulated hypothalamic-pituitary-adrenocortical (HPA) axis stress response has been reported among individuals with prenatal substance exposure and those with early adversity exposure. However, few researchers have examined the combined effects of these risk factors. Patterns of HPA reactivity among maltreated foster children with and without…

  14. Use of a crop and job specific exposure matrix for estimating cumulative exposure to triazine herbicides among females in a case-control study in the Central Valley of California.

    PubMed

    Young, H A; Mills, P K; Riordan, D; Cress, R

    2004-11-01

    To determine if a job exposure matrix (JEM) could be developed using the California Department of Pesticide Regulation Pesticide Usage Database in conjunction with crop, time, and county specific self reported work history and to determine if this was a feasible method to obtain exposure estimates to triazine herbicides. Agricultural work histories were gathered from women enrolled in a population based case-control study of ovarian cancer cases and random controls. The work histories were used in conjunction with the database to construct job exposure matrices which took into account weightings for job type, work location, and crop. Cumulative exposure estimates were determined for 98 study subjects. Mean exposure estimates were similar for cases and controls. The exposure estimates were robust and insensitive to varying job weight assumptions. The estimates from the original weights were highly correlated with those constructed using the conservative and maximum weights. Estimates from all three schemes produced similar multivariate age adjusted odds ratios comparing cases and controls. There was a high degree of agreement in categorised quartiles of exposure between the original and conservative, and original and maximum weights. The exposure estimate from the JEM provides a ranking of exposure within the study population that can be utilised as an "exposure score" with which to compare groups. Although it is not an absolute exposure measurement, it does offer a substantial advance over dichotomous categories based on self report of herbicide use, particularly when subjects are unlikely to recall specific names and dates of use of herbicides.

  15. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District

    USGS Publications Warehouse

    Beyer, W. Nelson; Franson, J. Christian; French, John B.; May, Thomas; Rattner, Barnett A.; Shearn-Bochsler, Valerie I.; Warner, Sarah E.; Weber, John; Mosby, David

    2013-01-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000–3,200 mg Pb/kg. Analyses of earthworms [33–4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11–3.0 (reference) and 1.3–30 (contaminated) and American robin (Turdus migratorius) = 0.43–8.5 (reference) and 7.6–72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32 %) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9 %) with systemic toxic effects, and 4 (12 %) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58–82 % in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

  16. Toxic exposure of songbirds to lead in the Southeast Missouri Lead Mining District.

    PubMed

    Beyer, W Nelson; Franson, J Christian; French, John B; May, Thomas; Rattner, Barnett A; Shearn-Bochsler, Valerie I; Warner, Sarah E; Weber, John; Mosby, David

    2013-10-01

    Mining and smelting in the Southeast Missouri Lead Mining District has caused widespread contamination of soils with lead (Pb) and other metals. Soils from three study sites sampled in the district contained from approximately 1,000-3,200 mg Pb/kg. Analyses of earthworms [33-4,600 mg Pb/kg dry weight (dw)] collected in the district showed likely high Pb exposure of songbirds preying on soil organisms. Mean tissue Pb concentrations in songbirds collected from the contaminated sites were greater (p < 0.05) than those in songbirds from reference sites by factors of 8 in blood, 13 in liver, and 23 in kidney. Ranges of Pb concentrations in livers (mg Pb/kg dw) were as follows: northern cardinal (Cardinalis cardinalis) = 0.11-3.0 (reference) and 1.3-30 (contaminated) and American robin (Turdus migratorius) = 0.43-8.5 (reference) and 7.6-72 (contaminated). Of 34 adult and juvenile songbirds collected from contaminated sites, 11 (32%) had hepatic Pb concentrations that were consistent with adverse physiological effects, 3 (9%) with systemic toxic effects, and 4 (12%) with life-threatening toxic effects. Acid-fast renal intranuclear inclusion bodies, which are indicative of Pb poisoning, were detected in kidneys of two robins that had the greatest renal Pb concentrations (952 and 1,030 mg/kg dw). Mean activity of the enzyme delta-aminolevulinic acid dehydratase (ALAD) in red blood cells, a well-established bioindicator of Pb poisoning in birds, was decreased by 58-82% in songbirds from the mining sites. We conclude that habitats within the mining district with soil Pb concentrations of ≥1,000 mg Pb/kg are contaminated to the extent that they are exposing ground-feeding songbirds to toxic concentrations of Pb.

  17. Childhood lead exposure and uptake in teeth in the Cleveland area during the era of leaded gasoline.

    PubMed

    Robbins, Norman; Zhang, Zhong-Fa; Sun, Jiayang; Ketterer, Michael E; Lalumandier, James A; Shulze, Richard A

    2010-09-01

    Childhood uptake of lead from exposure to atmospheric leaded gasoline in the United States has been studied using mainly blood lead levels. Since reliable blood lead techniques were used only after the peak use of leaded gasoline, the prior exposure history is unclear. The well-documented decline in blood lead levels after the mid-1970s could represent the continuation of a historic steady decline in exposure from many sources. Alternatively, the post-1970s decline might represent the declining phase of a unimodal rise and fall corresponding closely to usage of leaded gasoline. To assess these possibilities, lead concentration and 207Pb/206Pb isotope ratios were measured in the enamel of permanent molar teeth formed between 1936 and 1993 in mainly African-American donors who grew up in the Cleveland area. Tooth enamel preserves the lead concentration and isotope ratio that prevails during tooth formation. Historical trends in enamel lead concentration were significantly correlated with surrogates of atmospheric lead exposure: lead in sediments of two dated Lake Erie cores, and lead consumed in gasoline. About two-thirds of the total lead uptake into enamel in this period was attributable to leaded gasoline, and the remainder to other sources (e.g. paint). Enamel 207Pb/206Pb isotope ratios were similar to those of one lake sediment. Multivariate analysis revealed significant correlation in neighborhoods with higher levels of traffic, and including lake sediment data, accounted for 53% of the variation in enamel lead levels. Enamel lead concentration was highly correlated with reported African-American childhood blood levels. The extrapolated peak level of 48microg/dL (range 40 to 63) is associated with clinical and behavioral impairments, which may have implications for adults who were children during the peak gasoline lead exposure. In sum, leaded gasoline emission was the predominant source of lead exposure of African-American Cleveland children during the latter

  18. Investigation of lead concentrations in whole blood, plasma and urine as biomarkers for biological monitoring of lead exposure.

    PubMed

    Sommar, Johan Nilsson; Hedmer, Maria; Lundh, Thomas; Nilsson, Leif; Skerfving, Staffan; Bergdahl, Ingvar A

    2014-01-01

    Lead in blood is a major concept in biomonitoring of exposure but investigations of its alternatives are scarce. The aim of the study was to describe different lead biomarkers' variances, day-to-day and between individuals, estimating their fraction of the total variance. Repeated sampling of whole blood, plasma and urine were conducted for 48 lead-exposed men and 20 individuals under normal environmental lead exposure, in total 603 measurements. For lead workers, the fraction of the total variance attributed to differences between individuals was 91% for whole-blood lead (geometric mean 227 μg/l; geometric standard deviation (GSD): 1.55 μg/l); plasma 78% (0.57 μg/l; GSD: 1.84 μg/l); density-adjusted urine 82%; and unadjusted urine 75% (23.7 μg/l; GSD: 2.48 μg/l). For the individuals under normal lead exposure, the corresponding fractions were 95% of the total variance for whole blood (20.7 μg/l; GSD: 8.6 μg/l), 15% for plasma (0.09 μg/l; GSD: 0.04 μg/l), 87% for creatinine-adjusted urine and 34% for unadjusted (10.8 μg/l; GSD: 6.7 μg/l). Lead concentration in whole blood is the biomarker with the best ability to discriminate between individuals with different mean concentration. Urinary and plasma lead also performed acceptably in lead workers, but at low exposures plasma lead was too imprecise. Urinary adjustments appear not to increase the between-individual fraction of the total variance among lead workers but among those with normal lead exposure.

  19. Interrelations of lead levels in bone, venous blood, and umbilical cord blood with exogenous lead exposure through maternal plasma lead in peripartum women.

    PubMed Central

    Chuang, H Y; Schwartz, J; Gonzales-Cossio, T; Lugo, M C; Palazuelos, E; Aro, A; Hu, H; Hernandez-Avila, M

    2001-01-01

    Recent research has raised the possibility that fetal lead exposure is not estimated adequately by measuring lead content in maternal whole blood lead because of the variable partitioning of lead in whole blood between plasma and red blood cells. Lead in maternal plasma may derive in large part from maternal bone lead stores. In this study we aimed to estimate the contribution of maternal whole blood lead, maternal bone lead levels, and environmental lead to umbilical cord blood lead levels (as a measure of fetal lead exposure). In the model, we assumed that lead from all of these sources reaches the fetus through the maternal plasma lead pathway. In 1994-1995, we recruited 615 pregnant women for a study of lead exposure and reproductive outcomes in Mexico City. We gathered maternal and umbilical cord blood samples within 12 hr of each infant's delivery and measured maternal lead levels in cortical bone and trabecular bone by a K-X-ray fluorescence (K-XRF) instrument within 1 month after delivery. We administered a questionnaire to assess use of lead-glazed ceramics (LGC) to cook food and we obtained data on regional air lead levels during the 2 months before delivery. We used structural equation models (SEMs) to estimate plasma lead as the unmeasured (latent) variable and to quantify the interrelations of plasma lead, the other lead biomarkers, and environmental lead exposure. In the SEM analysis, a model that allowed plasma lead to vary freely from whole blood lead explained the variance of cord blood lead (as reflected by a total model R(2); R(2) = 0.79) better than did a model without plasma lead (r(2) = 0.67). Cortical bone lead, trabecular bone lead, use of LGC, and mean air lead level contributed significantly to plasma lead. The exchange of lead between plasma and red blood cells was mostly in the direction of plasma to cells. According to the final model, an increase in trabecular bone lead and cortical bone lead was associated with increases in cord blood

  20. A preliminary estimate of the EUVE cumulative distribution of exposure time on the unit sphere. [Extreme Ultra-Violet Explorer

    NASA Technical Reports Server (NTRS)

    Tang, C. C. H.

    1984-01-01

    A preliminary study of an all-sky coverage of the EUVE mission is given. Algorithms are provided to compute the exposure of the celestial sphere under the spinning telescopes, taking into account that during part of the exposure time the telescopes are blocked by the earth. The algorithms are used to give an estimate of exposure time at different ecliptic latitudes as a function of the angle of field of view of the telescope. Sample coverage patterns are also given for a 6-month mission.

  1. A preliminary estimate of the EUVE cumulative distribution of exposure time on the unit sphere. [Extreme Ultra-Violet Explorer

    NASA Technical Reports Server (NTRS)

    Tang, C. C. H.

    1984-01-01

    A preliminary study of an all-sky coverage of the EUVE mission is given. Algorithms are provided to compute the exposure of the celestial sphere under the spinning telescopes, taking into account that during part of the exposure time the telescopes are blocked by the earth. The algorithms are used to give an estimate of exposure time at different ecliptic latitudes as a function of the angle of field of view of the telescope. Sample coverage patterns are also given for a 6-month mission.

  2. Mechanisms Leading to Rhythm Cessation in the Respiratory PreBötzinger Complex Due to Piecewise Cumulative Neuronal Deletions1,2,3

    PubMed Central

    Song, Hanbing; Hayes, John A.; Vann, Nikolas C.; Drew LaMar, M.

    2015-01-01

    Abstract The mammalian breathing rhythm putatively originates from Dbx1-derived interneurons in the preBötzinger complex (preBötC) of the ventral medulla. Cumulative deletion of ∼15% of Dbx1 preBötC neurons in an in vitro breathing model stops rhythmic bursts of respiratory-related motor output. Here we assemble in silico models of preBötC networks using random graphs for structure, and ordinary differential equations for dynamics, to examine the mechanisms responsible for the loss of spontaneous respiratory rhythm and motor output measured experimentally in vitro. Model networks subjected to cellular ablations similarly discontinue functionality. However, our analyses indicate that model preBötC networks remain topologically intact even after rhythm cessation, suggesting that dynamics coupled with structural properties of the underlying network are responsible for rhythm cessation. Simulations show that cumulative cellular ablations diminish the number of neurons that can be recruited to spike per unit time. When the recruitment rate drops below 1 neuron/ms the network stops spontaneous rhythmic activity. Neurons that play pre-eminent roles in rhythmogenesis include those that commence spiking during the quiescent phase between respiratory bursts and those with a high number of incoming synapses, which both play key roles in recruitment, i.e., recurrent excitation leading to network bursts. Selectively ablating neurons with many incoming synapses impairs recurrent excitation and stops spontaneous rhythmic activity and motor output with lower ablation tallies compared with random deletions. This study provides a theoretical framework for the operating mechanism of mammalian central pattern generator networks and their susceptibility to loss-of-function in the case of disease or neurodegeneration. PMID:26465010

  3. Developmental exposure to a mixture of two mechanistically distinct antiandrogens results in cumulative adverse reproductive effects in adult male rats

    EPA Science Inventory

    Typically, toxicological studies have focused on the adverse effects from exposure to single chemicals. However, endocrine disrupting chemicals (EDCs) are detected in the environment as mixtures. Empirical evidence suggests that mixtures of EDCs with the same mechanism of action...

  4. Renal ultrastructure, renal function, and parameters of lead toxicity in workers with different periods of lead exposure

    PubMed Central

    CramÉr, Kim; Goyer, Robert A.; Jagenburg, Rudolf; Wilson, Marion H.

    1974-01-01

    Cramér, K., Goyer, R. A., Jagenburg, R., and Wilson, Marion H. (1974).British Journal of Industrial Medicine,31, 113-127. Renal ultrastructure, renal function, and parameters of lead toxicity in workers with different periods of lead exposure. Renal biopsies were obtained from five men with heavy occupational exposure to lead and compared with studies of their renal function and parameters of lead toxicity. Two men had lead exposure of less than one year while three men had been exposed for from four to more than 30 years. In addition, renal function studies were performed in two men from whom renal biopsies could not be obtained. Their lead exposures were five and 12 years, respectively. Significantly lower plasma levels, when compared with non-exposed controls, were found for proline, valine, tyrosine, and phenylalanine although no excessive aminoaciduria was found. Renal function tests were normal in all except for a reduced glomerular filtration rate (GFR) in one worker. Plasma ALA was measured by a new and highly specific method and ALA clearance was found to follow GFR closely. Those workers with prolonged lead exposure showed a lower urinary lead excreation. Typical lead-induced intranuclear inclusion bodies were found only in those with short exposure. The ultrastructural changes were localized to the proximal tubules, while the glomeruli were only nonspecifically affected. Mitochondrial changes were found in all men. Reasons for the decrease in inclusion body formation in chronic lead nephropathy are uncertain but may be due to an increased rate of renal cell turnover or a consequence of chelation therapy. Images PMID:4830763

  5. Cumulative exposure to ritonavir-boosted atazanavir is associated with cholelithiasis in patients with HIV-1 infection.

    PubMed

    Nishijima, Takeshi; Shimbo, Takuro; Komatsu, Hirokazu; Hamada, Yohei; Gatanaga, Hiroyuki; Kikuchi, Yoshimi; Oka, Shinichi

    2014-05-01

    This study aimed to examine the effect of long-term treatment with ritonavir-boosted atazanavir (atazanavir/ritonavir) on cholelithiasis. A single-centre, cross-sectional study was conducted to elucidate the prevalence of cholelithiasis in patients with HIV-1 infection who underwent abdominal ultrasonography between January 2004 and March 2013. Univariate and multivariate logistic regression analyses were applied to estimate the effects of >2 years of atazanavir/ritonavir exposure on cholelithiasis as the primary exposure. Of the 890 study patients, 84 (9.4%) had >2 years of atazanavir/ritonavir exposure. Cholelithiasis was twice as frequent in those treated for >2 years with atazanavir/ritonavir [15 (18%) of 84 patients] compared with those treated for <2 years [72 (8.9%) of 806 patients] (P = 0.018). Univariate analysis showed a significant association between >2 years of atazanavir/ritonavir exposure and cholelithiasis (OR = 2.216; 95% CI = 1.206-4.073; P = 0.010) and the association almost persisted in multivariate analysis (adjusted OR = 1.806; 95% CI = 0.922-3.537; P = 0.085). Long-term treatment (>2 years) with other commonly used protease inhibitors, such as ritonavir-boosted lopinavir and ritonavir-boosted darunavir, was not associated with cholelithiasis in univariate and multivariate analysis. Additional analysis showed that >1 year of exposure to atazanavir/ritonavir was significantly associated with cholelithiasis (OR = 1.857; 95% CI = 1.073-3.214; P = 0.027), whereas >1 year of exposure to ritonavir-boosted lopinavir and ritonavir-boosted darunavir was not. Long-term treatment of patients with HIV-1 infection for >2 years with atazanavir/ritonavir was associated with an increased risk of cholelithiasis compared with patients with shorter exposure. Long-term exposure to atazanavir/ritonavir appears to increase the risk of cholelithiasis in patients with HIV-1 infection.

  6. Change in childhood lead exposure prevalence with new reference level.

    PubMed

    Leafe, Morgan; Irigoyen, Matilde; DeLago, Cynthia; Hassan, Amman; Braitman, Leonard

    2015-06-01

    In 2012, the Centers for Disease Control and Prevention changed the "actionable" reference blood lead level from 10 μg/dL to 5 μg/dL, representing the highest 2.5 percentile of lead levels nationwide. In a high-risk urban community, the prevalence of children classified as lead exposed increased ninefold, from 1% to 9.1% (p < .0001) with the new reference level. This dramatic increase in the prevalence of children newly classified as lead exposed will require additional health care and public health resources for tracking, surveillance, and home lead abatement.

  7. Estimation of the cumulated exposure to polychlorinated dibenzo-p-dioxins/furans and standardized mortality ratio analysis of cancer mortality by dose in an occupationally exposed cohort.

    PubMed Central

    Flesch-Janys, D; Steindorf, K; Gurn, P; Becher, H

    1998-01-01

    For a cohort of 1189 male German former herbicide and insecticide workers with exposure to polychlorinated dibenzo-p-dioxins and -furans (PCDD/F), we report an extended standardized mortality ratio (SMR) analysis based on a new quantitative exposure index. This index characterizes the cumulative lifetime exposure by integrating the estimated concentration of PCDD/F at every point in time (area under the curve). Production department-specific dose rates were derived from blood levels and working histories of 275 workers by applying a first-order kinetic model. These dose rates were used to estimate exposure levels for all cohort members. Total mortality was elevated in the cohort; 413 deaths yielded an SMR of 1.15 (95% confidence interval [Cl] 1.05, 1.27) compared to the mortality of the population of Germany. Overall cancer mortality (n = 124) was significantly increased (SMR = 1.41, 95% Cl 1.17, 1.68). Various cancer sites showed significantly increased SMRs. The exposure index was used for an SMR analysis of total cancer mortality by dose. For 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) a significant trend (p = 0.01) for the SMRs with increasing cumulative PCDD/F exposure was observed. The SMR in the first exposure quartile (0-125.2 ng/kg x years) was 1.24 (95% Cl 0.82, 1.79), increasing to 1.73 (95% Cl 1.21, 2.40) in the last quartile (> or = 2503.0 ng/kg x years). For all congeners combined as toxic equivalencies (TEQ) using international toxic equivalency factors, a significant increase in cancer mortality was observed in the second quartile (360.9-1614.4 ng/kg x years, SMR 1.64; 95% Cl 1.13, 2.29) and the fourth quartile (> or = 5217.7 ng/kg x years TEQ, SMR 1.64, 95% Cl 1.13, 2.29). The trend test was not significant. The results justify the use of this cohort for a quantitative risk assessment for TCDD and to a lesser extent for TEQ. Images Figure 1 PMID:9599713

  8. Lead exposure in Latin America and the Caribbean. Lead Research Group of the Pan-American Health Organization.

    PubMed Central

    Romieu, I; Lacasana, M; McConnell, R

    1997-01-01

    As a result of the rapid industrialization of Latin America and the Caribbean during the second half of this century, exposure to lead has become an increasingly important problem. To obtain an estimate of the magnitude of lead exposure in the region, we carried out a survey and a literature search on potential sources of lead exposure and on blood lead concentrations. Sixteen out of 18 Latin American and 2 out of 10 Caribbean countries responded to the survey. Lead in gasoline remains a major problem, although the lead content has decreased in many countries in the last few years. The impact of leaded fuel is more important in urban settings, given their high vehicular density. Seventy-five percent of the population of the region lives in urban areas, and children younger than 15 years of age, the most susceptible group, comprise 30% of the population. Other sources of lead exposure identified in the region included industrial emissions, battery recycling, paint and varnishes, and contaminated food and water. Lead is recognized as a priority problem by national authorities in 72% of the countries that responded to the survey, and in 50% of the countries some legislation exists to regulate the lead content in certain products. However, compliance is low. There is an urgent need for a broad-based coalition between policy makers, industry, workers, unions, health care providers, and the community to take actions to reduce environmental and occupational lead exposures in all the Latin American and Caribbean countries. Images Figure 1. Figure 2. PMID:9189704

  9. Assessing the safety of co-exposure to food packaging migrants in food and water using the maximum cumulative ratio and an established decision tree.

    PubMed

    Price, Paul; Zaleski, Rosemary; Hollnagel, Heli; Ketelslegers, Hans; Han, Xianglu

    2014-01-01

    Food contact materials can release low levels of multiple chemicals (migrants) into foods and beverages, to which individuals can be exposed through food consumption. This paper investigates the potential for non-carcinogenic effects from exposure to multiple migrants using the Cefic Mixtures Ad hoc Team (MIAT) decision tree. The purpose of the assessment is to demonstrate how the decision tree can be applied to concurrent exposures to multiple migrants using either hazard or structural data on the specific components, i.e. based on the acceptable daily intake (ADI) or the threshold of toxicological concern. The tree was used to assess risks from co-exposure to migrants reported in a study on non-intentionally added substances (NIAS) eluting from food contact-grade plastic and two studies of water bottles: one on organic compounds and the other on ionic forms of various elements. The MIAT decision tree assigns co-exposures to different risk management groups (I, II, IIIA and IIIB) based on the hazard index, and the maximum cumulative ratio (MCR). The predicted co-exposures for all examples fell into Group II (low toxicological concern) and had MCR values of 1.3 and 2.4 (indicating that one or two components drove the majority of the mixture's toxicity). MCR values from the study of inorganic ions (126 mixtures) ranged from 1.1 to 3.8 for glass and from 1.1 to 5.0 for plastic containers. The MCR values indicated that a single compound drove toxicity in 58% of the mixtures. MCR values also declined with increases in the hazard index for the screening assessments of exposure (suggesting fewer substances contributed as risk potential increased). Overall, it can be concluded that the data on co-exposure to migrants evaluated in these case studies are of low toxicological concern and the safety assessment approach described in this paper was shown to be a helpful screening tool.

  10. Lead exposure in Laysan albatross adults and chicks in Hawaii: prevalence, risk factors, and biochemical effects.

    PubMed

    Work, T M; Smith, M R

    1996-07-01

    Prevalence of lead exposure and elevated tissue lead was determined in Laysan albatross (Diomedea immutabilis) in Hawaii. The relationship between lead exposure and proximity to buildings, between elevated blood lead and droopwing status, and elevated liver lead and presence of lead-containing paint chips in the proventriculus in albatross chicks was also examined. Finally, the effects of lead on the enzyme delta-aminolevulinic acid dehydratase (ALAD) was determined. There was a significant association between lead exposure or elevated tissue lead and proximity to buildings in albatross chicks and presence of lead paint chips in the proventriculus and elevated liver lead in carcasses. Although there was a significant association between elevated blood lead and droopwing chicks, there were notable exceptions. Prevalence of elevated tissue lead in albatross chicks was highest on Sand Island Midway and much less so on Kauai and virtually nonexistent in other areas. Prevalence of lead exposure decreased as numbers of buildings to which chicks were exposed on a given island decreased. Laysan albatross adults had minimal to no lead exposure. There was a significant negative correlation between blood lead concentration and ALAD activity in chicks. Based on ALAD activity, 0.03-0.05 microg/ml was the no effect range for blood lead in albatross chicks.

  11. Lead exposure in Laysan albatross adults and chicks in Hawaii: Prevalence, risk factors, and biochemical effects

    USGS Publications Warehouse

    Work, Thierry M.; Smith, M.R.

    1996-01-01

    Prevalence of lead exposure and elevated tissue lead was determined in Laysan albatross (Diomedea immutabilis) in Hawaii. The relationship between lead exposure and proximity to buildings, between elevated blood lead and droopwing status, and elevated liver lead and presence of lead-containing paint chips in the proventriculus in albatross chicks was also examined. Finally, the effects of lead on the enzyme δ-amino-levulinic acid dehydratase (ALAD) was determined. There was a significant association between lead exposure or elevated tissue lead and proximity to buildings in albatross chicks and presence of lead paint chips in the proventriculus and elevated liver lead in carcasses. Although there was a significant association between elevated blood lead and droopwing chicks, there were notable exceptions. Prevalence of elevated tissue lead in albatross chicks was highest on Sand Island Midway and much less so on Kauai and virtually nonexistent in other areas. Prevalence of lead exposure decreased as numbers of buildings to which chicks were exposed on a given island decreased. Laysan albatross adults had minimal to no lead exposure. There was a significant negative correlation between blood lead concentration and ALAD activity in chicks. Based on ALAD activity, 0.03-0.05 μg/ml was the no effect range for blood lead in albatross chicks.

  12. Toxic lead exposure in the urban rock dove

    SciTech Connect

    DeMent, S.H.; Chisolm, J.J. Jr.; Eckhaus, M.A.; Strandberg, J.D.

    1987-04-01

    Thirteen adult urban rock doves (Columba livia), 12 captured alive and one found dead, were studied from the Baltimore zoo. The mean concentration of lead in the blood for the 12 live birds was 184.5 +/- 531.2 (range 10.5-1,870 micrograms/dl). Three of the 13 birds with high measured blood and tissue lead concentrations were found at necropsy with lead shot pellets in their gizzards. Correlations were not found between concentrations of lead in the blood and body weight or hematocrit. Conversely, high correlations were noted between concentrations of lead in the blood and measured liver and kidney concentrations (r = 0.946, P less than 0.01; r = 0.993, P less than 0.01, respectively). Numbers of intranuclear acid-fast inclusions per 10 consecutive fields (100x oil immersion lens) correlated well with measured kidney lead concentrations (r = 0.990, P less than 0.001).

  13. Lead in housing paints: an exposure source still not taken seriously for children lead poisoning in China.

    PubMed

    Lin, G Z; Peng, R F; Chen, Q; Wu, Z G; Du, L

    2009-01-01

    After prohibitions on lead gasoline additives, which have proved to be a public health accomplishment world wide, many countries focus on other exposure source of children lead poisoning. Removing lead from paints is one of the important measures. Although there have been regulatory limits on lead in paints in China, evidence reported in this article indicates that lead-based paints were very common in new paints available for housing and in existing residential paints. Twenty-nine of 58 new paint samples (50%) had lead content equal to or exceeding 600 ppm, including 14 (24%) equal to or exceeding 5000 ppm. The highest sample contained 153,000 ppm lead, about 15% of the paint weight. Thirty-two new paints (55%) contained "soluble" lead exceeding 90 ppm, the current lead limit on paints in China. Of the existing paints, 16 of 28 samples of existing paint (57%) collected from 24 kindergartens and primary schools had lead concentrations equal to or exceeding 600 ppm, including six samples (21%) equal to or exceeding 5000 ppm. The highest concentration sample contained 51,800 ppm lead, accounting for 5.2% of the paint weight. It has been shown in many areas that paint lead is a major exposure source for lead poisoning in children. This is particularly true after the phasing out of lead from gasoline. Effective limitation on lead content in new paint, and lead hazard control measures directed towards existing paint, could reduce children blood lead levels (BLLs). There has been a lead standard for paints in China since 1986 and a stricter limit was introduced in recent years. Governments should take it seriously and enforce regulations, commit a long-term challenge to eliminate paint lead as it is the threat to current and the next generation.

  14. An empirical comparison of lead exposure pathway models.

    PubMed Central

    Succop, P; Bornschein, R; Brown, K; Tseng, C Y

    1998-01-01

    Structural equation modeling is a statistical method for partitioning the variance in a set of interrelated multivariate outcomes into that which is due to direct, indirect, and covariate (exogenous) effects. Despite this model's flexibility to handle different experimental designs, postulation of a causal chain among the endogenous variables and the points of influence of the covariates is required. This has motivated the researchers at the University of Cincinnati Department of Environmental Health to be guided by a theoretical model for movement of lead from distal sources (exterior soil or dust and paint lead) to proximal sources (interior dust lead) and then finally to biologic outcomes (handwipe and blood lead). The question of whether a single structural equation model built from proximity arguments can be applied to diverse populations observed in different communities with varying lead amounts, sources, and bioavailabilities is addressed in this article. This reanalysis involved data from 1855 children less than 72 months of age enrolled in 11 studies performed over approximately 15 years. Data from children residing near former ore-processing sites were included in this reanalysis. A single model adequately fit the data from these 11 studies; however, the model needs to be flexible to include pathways that are not frequently observed. As expected, the more proximal sources of interior dust lead and handwipe lead were the most important predictors of blood lead; soil lead often had a number of indirect influences. A limited number of covariates were also isolated as usually affecting the endogenous lead variables. The blood lead levels surveyed at the ore-processing sites were comparable to and actually somewhat lower than those reported in the the Third National Health and Nutrition Examination Survey. Lessened bioavailability of the lead at certain of these sites is a probable reason for this finding. PMID:9860917

  15. Pediatric lead exposure and the water crisis in Flint, Michigan.

    PubMed

    DeWitt, Rachel D

    2017-02-01

    Changing the source of the water supply to save money had the unintended consequence of exposing residents of Flint, Mich., to elevated lead levels in their drinking water. A study done at Flint's Hurley Children's Hospital demonstrated that the incidence of elevated blood lead levels of children living in the affected area nearly doubled after the change in the water source. This article reviews the recommendations for lead screening and for reporting, following, and treating children with blood lead levels greater than 5 mcg/dL.

  16. Childhood Lead Exposure After the Phaseout of Leaded Gasoline: An Ecological Study of School-Age Children in Kampala, Uganda

    PubMed Central

    Graber, Lauren K.; Asher, Daniel; Anandaraja, Natasha; Bopp, Richard F.; Merrill, Karen; Cullen, Mark R.; Luboga, Samuel; Trasande, Leonardo

    2010-01-01

    Background Tetraethyl lead was phased out of gasoline in Uganda in 2005. Recent mitigation of an important source of lead exposure suggests examination and re-evaluation of the prevalence of childhood lead poisoning in this country. Ongoing concerns persist about exposure from the Kiteezi landfill in Kampala, the country’s capital. Objectives We determined blood lead distributions among Kampala schoolchildren and identified risk factors for elevated blood lead levels (EBLLs; ≥ 10 μg/dL). Analytical approach Using a stratified, cross-sectional design, we obtained blood samples, questionnaire data, and soil and dust samples from the homes and schools of 163 4- to 8-year-old children representing communities with different risks of exposure. Results The mean blood lead level (BLL) was 7.15 μg/dL; 20.5% of the children were found to have EBLL. Multivariable analysis found participants whose families owned fewer household items, ate canned food, or used the community water supply as their primary water source to have higher BLLs and likelihood of EBLLs. Distance < 0.5 mi from the landfill was the factor most strongly associated with increments in BLL (5.51 μg/dL, p < 0.0001) and likelihood of EBLL (OR = 4.71, p = 0.0093). Dust/soil lead was not significantly predictive of BLL/EBLL. Conclusions Lead poisoning remains highly prevalent among school-age children in Kampala. Confirmatory studies are needed, but further efforts are indicated to limit lead exposure from the landfill, whether through water contamination or through another mechanism. Although African nations are to be lauded for the removal of lead from gasoline, this study serves as a reminder that other sources of exposure to this potent neurotoxi