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 Mataro, 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/m(3)) 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.