Kalsbeek, H; Kwant, G W; Groeneveld, A; Backer Dirks, O; van Eck, A A; Theuns, H M
In December 1973 water fluoridation was discontinued in Tiel, the Netherlands. Six years later an epidemiological study was started, with the aim to investigate the consequences. In the period from 1979 to 1988 a yearly caries investigation was carried out in 15 year old children born and living in Tiel and children living in the control town of Culemborg, where the drinking water had never been fluoridated. The 15 year old children in 1979-1980 in Tiel had a 18% higher caries experience than the same age group in 1968-1969, to whom fluoridated water had been available from birth onward. In the same period a 28% decrease of the caries was found in Culemborg. In 1979-1980 the DMFS-index in Tiel was still 36% lower than in Culemborg. Between 1979-1980 and 1987-1988 the caries experience decreased in both towns.
Kalsbeek, H; Kwant, G W; Groeneveld, A; Dirks, O B; van Eck, A A; Theuns, H M
In 1973 the fluoridation of drinking water in the Dutch town of Tiel was discontinued. In order to monitor the effect of this measure, the caries experience in 15-year-old children was investigated annually from 1979 to 1988, both in Tiel and in Culemborg. In the latter town the drinking water had never been fluoridated. The caries data of 15-year-old children examined between 1968 and 1969 in Tiel (children having used fluoridated water from birth) and Culemborg were used as historical controls. In Tiel the mean number of DMFS increased between 1968/69 and 1979/80 from 10.8 to 12.7 (+18%) and decreased to 9.6 (-26%) in the following years; in 1987/88 the mean DMFS was 11% lower than in 1968/69. In Culemborg the mean DMFS score decreased between 1968/69 and 1987/88 from 27.7 to 7.7 (-72%). In 1968/69 the mean DMFS score in Tiel was 61% lower and in 1987/88 17% higher than in Culemborg. The question as to whether water fluoridation would have had an additional effect if it had been continued (presuming the application of existing preventive measures) cannot be answered, as there are no remaining communities with fluoridated water in The Netherlands.
Varela-Moreiras, G; Escudero, J M; Alonso-Aperte, E
The SENECA study started in 1988 and consisted of a random age- and sex-stratified sample of inhabitants of 19 European towns. A total of 2.100 elderly people were finally able to be included in the study. The present study includes results for total plasma homocysteine (tHcy) and the related vitamins folate, B12 and B6. Other style factors as alcohol consumption or smoking have been also evaluated. The lowest values for tHcy corresponded to Mediterranean countries (Portugal, Spain, and Greece), compared to central or northern european countries (Netherland or Belgium (differences higher than 4 micromol/l). In addition, an interesting north-south gradient is observed, with the lowest values for tHcy corresponding to Betanzos (Spain), 12.38 micromol/l followed by both centers in Portugal, whereas the highest concentrations are found in Maki (Poland), 21.92 pmol/I and Culemborg (Netherlands), 20.41 mircromol/l. The mean tHcy concentration for all the European centers was 15.98 micromol/l. Effect of sex has been also evaluated: those countries with the lowest tHcy concentration (i.e. Spain or Portugal) show significant (p < 0.01) higher tHcy concentration in men vs women, whereas these differences by sex are not observed in countries with the highest tHcy values. The effect of "aging" within the same individuals after ten years of follow up was also evaluated: a significant difference was observed for the same individuals in the 10-years period. Plasma folic acid was compared to tHcy values, resulting also in marked differences between north and southern countries. Plasma vitamin B12 also shows a close pattern. Either plasma folate or vitamin B12 were shown as strong predictors of tHcy. This effect was not observed for plasma vitamin B6. Total alcohol intake was positively and significantly (p < 0.01) correlated with tHcy ("no" intake corresponded with the lowest tHcy, 14.3 micromol/l vs "high" intake-over 30 g/d-with the highest tHcy, 17 micromol/l). The type of
van den Ancker, Hanneke; Jungerius, Pieter Dirk
A large part of the countryside roads on the Pleistocene sands of The Netherlands are dirt roads. Most are footpaths, but a small percentage are relatively heavily used by motorized vehicles. These latter roads are a cause subject of debate. Puddles and potholes develop during periods of wet weather, while dust whirls from the roads form during spells of dry weather as do washboard ripples. They cause problems for people living along these roads and tourists (walkers and bikers. The community of Ede (NL), like many other communities on the sand, wants to keep its 80 km of dirt roads because of the natural values they harbour as well as for their characteristic landscape quality and cultural heritage value. A part of the dirt roads in Ede is heavily used. In 2009, the community of Ede developed a decision model to support management of the dirt roads. Ede acknowledges that each dirt road is unique and asks for a tailor-made solution. Road maintenance measures include grading, making a camber, digging pits, applying loam or sandy loam. If problems become too large, one-way traffic can be an option. In more and more cases the dirt roads are barred for motorized through traffic (Gemeente Ede, 2009). As a reconnaissance we have studied the dirt roads of the Horabos/Horalaan over the last year. Incidentally we looked at other parts of the main Horalaan and the footpaths in the adjacent forest of Hoekelum. All dirt roads lie near the top of a Saalian push-moraine in which the upper course of dry valleys are present. Some results of the reconnaissance: - Most dirt roads sections in the Horabos lie lower than the surrounding terrain; - The problems develop in a short period of time during special weather conditions; - Certain dirt road sections e.g. those sections crossing a slight depression are quickly developing potholes; - Even a small slope of the road (< 2 degrees) causes water to flow over the road and form rills in the pavement. On preferential spots the rills
Jungerius, Pieter Dirk; van den Ancker, Hanneke; Arts, Andries; Borkent, Ido; Ketner-Oostra, Rita; Ketner, Pieter
most Natura-2000 species had disappeared from these areas. Discussion and recommendations From the Natura-2000 viewpoint the restoration measures were very successful as the terrain now classifies as habitat type 2330. Different views exist on how to further manage the terrain. One view is to try and create a steady-state situation by regularly removing part of the Corynephorus canescens vegetation and having an active erosion- and transport-zone while further increasing the erosivity of the wind by removing more trees. Another view is to let succession have its way, and see which species appear in the course of succession. As cells in successive stages are now available, we propose to test the different views and proceed with the monitoring of the terrains. Reference Ancker, J.A.M. van den, Everts, H., Jungerius, P.D. & Ketner-Oostra, R., 2002. Vooronderzoek herstel stuifzanden gemeente Bergen (Limburg). Rapport Stichting G&L, Ede, i.s.m. Rita Ketner en Ecologisch Advies & Onderzoeksbureau Everts & de Vries, i.o.v. de gemeente Bergen (Li).