Search

Study Objective and Design: In Aalsmeer, a horticultural community near the main international airport in The Netherlands, a more than fourfold increase in the incidence of haematopoietic malignancies in young people was observed between 1980 and 1985. In a population based case-control study, the association with local environmental factors was investigated., Participants: For each patient younger than 40 years of age (n = 14) diagnosed between 1975 and 1989, four age and sex matched controls were selected via local general practitioners., Methods: All parents of patients and controls completed a questionnaire on their lifestyle, living conditions, and health, for several years preceding each individual diagnosis. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated, matched, and, if necessary, stratified for neighbourhood., Main Results: Increased ORs were recorded for intensive use of petroleum products and pesticides by the patients themselves and their fathers: OR petroleum products: 8.0 (95% CI 2.2, 129.9) and 9.0 (1.0, 66.1) respectively; OR pesticides: 6.0 (0.6, 49.3) and 3.2 (1.0, 10.1) respectively. Swimming in a local pond was also significantly associated with the disease: OR = 5.3 (1.3, 17.4). In the 1970s this pond had been polluted by petroleum products and pesticides., Conclusions: The increased incidence of childhood haematopoietic malignancies in Aalsmeer may have been associated with several specific local environmental factors. Interpretation of the results, however, should take into account the fact that confidence intervals were wide because of the limited number of cases.

The Dutch part of Kempenland has been exposed to cadmium pollution since the last century. Experimental data suggest effects by cadmium on reproduction such as diminished fertility, decreased foetal growth, and specific malformations. Use was made of a historical cohort of dairy cows, ascertained from a surveillance program conducted by the regional Veterinary Health Service between 1976 and 1986. Ten dairy farms in the cadmium region were matched by size with 40 dairy farms from a reference area. Logistic models were used to calculate Odds (OR) and Rate Ratios (RR) and their 95% confidence interval. In total 4,039 exposed and 15,552 reference gestations were compared. The reasons for the slaughter of 574 exposed and of 2,824 reference cows were ascertained. A lower twinning rate [OR = 0.63 (0.47-0.84)] was found and more birth complications, for both calves [OR = 1.50 (1.25-1.80)] and cows [OR = 1.49 (1.24-1.79)]. More inseminations [OR = 1.20 (1.01-1.43)] were needed for conception in the exposed area. Deaths among twins [OR = 1.66 (0.90-3.07)] were not significantly higher. Perinatal death, premature death, age at, or reasons for, slaughter were not consistently different. These results are consistent with those of other observational and experimental studies. Extrapolation from these large domestic animals to humans is problematic, as is the more frequent extrapolation from rodents to humans. It can be concluded that longterm exposure to low levels of cadmium is associated with impaired reproduction in dairy cows.

In Aalsmeer, a horticultural community near the main international airport in the Netherlands, an incidence of haematopoietic malignancies in young people over four times the national mean was observed in the period 1980-1985. A population based case-control study investigated the association with local environmental factors. For each case younger than 40 years of age (n = 14), diagnosed between 1975 and 1989, four controls, matched for age and gender, were selected via local general practitioners. All parents of patients and controls completed a questionnaire on their life style, living conditions and health for several years preceding each individual diagnosis. Odds ratios (ORs) were calculated, matched and--if necessary--stratified for neighbourhood. Increased ORs were recorded for intensive use of petroleum products and pesticides, by the patients themselves and their fathers (OR petroleum products: 8.0, resp. 9.0; OR pesticides: 6.0, resp. 3.2). Most of these increases were statistically significant. Swimming in a local pond was also significantly associated with the disease (OR = 5.3); in the seventies this pond had been polluted by accidents with petroleum products and pesticides. contributed to the increase of the disease: ORs for several indirect exposure parameters were all above 2. It can be concluded that the increased incidence of childhood haematopoietic malignancies in Aalsmeer may have been associated with several specific local environmental factors. However, interpretation of the results should take into account that confidence intervals were wide, due to the necessarily limited number of cases.

Patterns in the occurrence of influenza-like symptoms after increases in ambient sulphur dioxide (SO2) concentrations, have been investigated. Three routinely collected sets of data were used: (a) air pollution, including SO2, as measured continuously by the National Air Monitoring System; (b) ambient outdoor air temperature as measured hourly by the Royal Dutch Meteorological Institute and (c) weekly influenza incidence as monitored by the Dutch Sentinel Practice Network. The region investigated has been confined to the three western provinces of the Netherlands. The data were expressed as weekly average values. To correct for autocorrelation the 'Box-Jenkins approach' to model time series was used. After correction for seasonal patterns and a log transformation the ARMA (autoregressive and moving average) models were identified. The relation between the time series has been assessed by a transfer function model. After correction for temperature and with a delay of two weeks, a significant association could be ascertained between the hourly SO2 concentration and influenza incidence. An association between lower temperature and increased influenza incidence one week later was established as well. A relation of air pollution and influenza with a delay of about two weeks is quite possible. However, 12 years may have been too short a period to correct for secular patterns and SO2 was probably only an indicator of air pollution. Further investigation seems warranted.

The border region between Belgium and The Netherlands, the Kempen, was found to be polluted with cadmium. The main route of pollution had been by air but some cadmium came by way of surface-water and solid waste. This resulted in an increase in the cadmium content of locally grown vegetables. The consequential exposure to cadmium of humans living in the area has been estimated using various methods and is approximately the FAO/WHO maximum allowable daily intake, smoking disregarded. Several studies of possible effects on public health were conducted. Among these studies were two geographic studies, one on hospital admissions for various non-malignant diseases and one on cancer-incidence. Two cohort studies on possible teratogenic effects in a non-occupationally exposed, non-smoking vegetarian population with a high fertility and good registration were also conducted. A survey on cadmium content of the urine and kidney damage in a longtime but non-occupationally exposed rural population and a reference population formed the main study. Also, a survey on cadmium content of the kidney samples of autopsied patients in a population based study and a reference population was conducted. Together these studies showed that the extra exposure had lead to an additional body-burden of cadmium resulting in various signs of malfunction. In consequence of the findings the Netherlands Ministry for Housing, Physical Planning and Environment appropriated money to cleanup contaminated gardens.