Environmental tobacco smoke interference in the assessment of the health impact of a municipal waste incinerator on children through urinary thioether assay

The urinary elimination of thioethers urinary thioethers (UT) was studied in 83 schoolchildren living in two different areas of the city of Matarَ, with special attention paid to the influence of a waste incinerator and of the smoking habits of their parents. The mean UT values were 8.79±3.23 and 7.52±3.23 mmol/mol creatinine in the area close to the incinerator (A1) and in the area far away from it (A2) respectively (statistically n.s.). Children exposed to environmental tobacco smoke (ETS) at home presented increased levels of UT (8.60±3.11 vs 5.93±3.22 mmol/mol creatinine; P=0.002). Considering the two exposures together (waste incinerator and ETS), no differences were found between the two areas studied (A1 and A2) in non-exposed (ETS) children, whereas slight differences were found when comparing highest ETS exposed children from the two areas (10.18±2.70 vs 8.00±3.42 mmol/mol creatinine; P=0.04). Exposure to ETS could affect health more than pollutants from a waste incinerator and may interfere with non-selective assays such as urinary thioethers.