Individual susceptibility and prevention of occupational diseases: scientific and ethical issues.

Genetic testing of employees is controversial; objections have been raised with regard to privacy, right to work, and the relevance of the tests. A study is being conducted on "the ethical, social, and scientific problems related to the application of genetic screening and genetic monitoring for employees in the context of a European approach to health and safety at work." A conceptual model is proposed of the complex interactions between exposure, acquired and inherited susceptibility, and risk for disease. The validity of tests for determining genotype and phenotype and their relevance for disease must be evaluated critically to provide an objective basis for ethical discussions. The acceptability of such tests is related to a number of issues, which are identified and discussed.

Blood levels of polychlorinated dibenzodioxins, polychlorinated dibenzofurans and polychlorinated biphenyls in the general population of a Spanish Mediterranean city.

Polychlorinated dibenzodioxins (PCDDs), Polychlorinated dibenzofurans (PCDFs) and Polychlorinated biphenyls (PCBs) are among the most toxic environmental pollutants. We determined blood levels of these compounds in a population sample of the city of Mataró, Spain. Blood samples were drawn from a randomly selected sample of 198 subjects, of both genders, aged 18 to 69 years. These samples were pooled into 10 groups for laboratory analysis. For males, total level of PCDDs was 505.7 ppt, of PCDFs was 26.7 ppt, and the international toxic equivalent (I-TEQ) was 12.5. For females the levels were 739 ppt, 28.8 ppt and 14.71-TEQ, respectively. The most important contributors to the total I-TEQ were HexaCDD, PentaCDD and PentaCDF. The blood concentration of total PCBs was 2.02 mg/l in males, and 1.58 mg/l in females. Levels of PCDDs, PCDFs and PCBs increased by age in both sexes. The levels of PCDDs and PCDFs in residents of this Mediterranean city are among the lowest observed in industrialized countries.

Biomonitoring study of people living near or working at a municipal solid-waste incinerator before and after two years of operation.

The authors conducted a biomonitoring study in the town of Mataró, Spain, of 104 subjects who lived near (i.e., within 0.5-1.5 km) an incinerator, 97 subjects who lived far (i.e., within 3.5 km-4.0 km) from an incinerator, and 17 workers at a new municipal solid-waste incinerator. The study commenced before the incinerator started functioning in 1995, and 2 y later (1977) the authors undertook the final part of the study. Dioxins, furans, and polychlorinated biphenyls were studied in pooled blood samples (n = 22), and individual blood and urine samples were analyzed for the detection of lead, chromium, cadmium, and mercury. In 1995, dioxin blood levels were low-both among those living close to the incinerator (mean = 13.5 ng international-dioxin toxic equivalents/kg fat) and among those living far away (mean = 13.4 ng international-dioxin toxic equivalents/kg fat). In 1997, dioxin and polychlorinated biphenyl levels had increased in both groups of residents by approximately 25% and 12%, respectively. (The increase in dioxin levels was about 10% when the authors took into account the mean of two repeated quality-control analyses.) Blood lead levels decreased, but no difference was observed for chromium, cadmium, and mercury. Minimal changes were seen among workers. Given the low dioxin stack emissions from this plant (mean = 2.5-0.98 ng international-dioxin toxic equivalents/m3) and that the blood dioxin levels did not depend on distance of residence from the incinerator, it would appear unlikely that the small increase in dioxin blood levels resulted from the incinerator's emissions.