Health effects of environmental exposure to cadmium: objectives, design and organization of the cadmibel study: a cross-sectional morbidity study carried out in Belgium from 1985 to 1989

Abstract

Cadmium is a cumulative environmental pollutant. For the general population mainly exposed by the oral route and through tobacco smoke inhalation, the kidney is the critical organ. Belgium is the principal producer of cadmium in Europe, and certain areas of the country are polluted by cadmium mainly because of past emissions from nonferrous industries. Preliminary studies carried out in one polluted area have suggested that environmental pollution might lead to an increased uptake of cadmium by the human body and possibly to health effects. Thus, a large-scale morbidity study has been initiated to assess the validity of this hypothesis. The present paper describes the protocol of this study. Its main objectives are to determine to what extent environmental exposure to cadmium resulting from industrial emissions may lead to accumulation of the metal in the human organism; to establish whether or not environmental exposure may induce renal changes and/or influence blood pressure; and to assess the acceptable internal dose of cadmium for the general population. The study design takes advantage of the fact that biological indicators of exposure, body burden, and early nephrotoxic effects of cadmium are available, which increase the likelihood of detecting a cause-effect relationship.

Mortality by cancer in groups of the Belgian population with a moderately increased intake of arsenic

“…Thus, to avoid these sources of bias, the rural zones in the northern part of the country, where an increased level of arsenic excretion had been observed, were retained for further analysis. It is noteworthy that in the populations of municipalities representative of areas A, B, and C the mean a A Area close to zinc smelters having received drinking water containing between 20 and 50 lg As/l until 1990; B area away from the smelters, drinking water with up to 20 lg As/l; C area moderately in¯uenced by zinc smelters and with less than 5 lg As/l of drinking water urinary excretion of arsenic amounted to 35, 11, and 12 lg As/24 h, respectively, and in area A the distance to the nearest smelter remained independently correlated with the urinary arsenic excretion after adjustments for covariates (e.g., sex, age, and, in men, intake of diuretics) [10]. An analysis of the data focusing on areas A, B, and C (with their grouped districts serving as the reference) showed a signi®cantly decreased prevalence of lung cancer in men living in area B.…”

“…In the ®rst step the population of the kingdom was chosen as the reference, but as marked dierences were noted between the northern and southern districts, subsequent analyses were restricted to the region with zinc smelters in operation and its control area, examined during the Cadmibel study [10]. The populations of the Maaseik and Turnhout districts were then pooled and classi®ed according to sex and age (nine 10-year age groups: 0±9 years, 10±19 years, Á Á Á, 80+ years) to serve as the common reference for calculation of the SRRs (``directly'' standardized rate ratios) [14] observed in areas A, B, and C. To avoid possible confounding eects by coal mines and chemical plants in the Maaseik and Turnhout dis- Fig.…”

“…More recently an extensive investigation, the Cadmibel study [10], assessed in the general population the health impairments related to environmental pollution by cadmium and created the opportunity for a study of arsenic absorption by the Belgian population. During this survey, performed between 1985 and 1989, urban (Charleroi and LieÁ ge) and rural (parts of the Maaseik and Turnhout districts) areas were investigated (Fig.…”

Capillary electrophoretic separation of serum proteins of workers occupationally exposed to heavy metals

“…In parenthesis was given a 95% confidence interval (CI) for the correlation coefficient. The occupational exposure of copper smelters to Pb, Cd, As and tobacco smoke increases the risk of many diseases, including liver diseases [27]. The hepatotoxic effects of environmental xenobiotics can be analysed through changes in the serum protein profile.…”

Review of trace element concentrations in biological specimens according to the TRACY protocol

“…The food and drinking habits were mentioned, medication, current and past occupation were asked for, and a statistically sucient number was present. The method was mentioned in a separate paper (Lauwerys et al 1990) and adequate quality control was performed by using (certi®ed) reference material, participation to intercomparison programs and testing for contamination. Table 2 shows the results of these studies.…”