Exposure of Puerto Rican children to environmental tobacco smoke.

BACKGROUND: Many studies of environmental tobacco smoke (ETS) have been conducted in northern, industrialized countries. As yet, however, no studies have been carried out on ETS exposure with nonsmokers living in tropical environments. METHODS: Urine specimens were collected from 175 healthy Puerto Rican children (2-11 years) living in an industrial area and were analyzed for cotinine, a quantitative biomarker for exposure to ETS. Their parents completed a questionnaire covering smoking habits. RESULTS: Seventy percent of children were exposed to ETS. Quantitatively, exposure to smoke in households consuming more than 1 pack per day (ppd) caused a doubling of cotinine excretion compared with households consuming less than 1 ppd. Smoke from mothers made the greatest contribution to cotinine, followed by smoke from fathers, with smoke from other persons having no effect. Degree of exposure was inversely related to age of the child. CONCLUSIONS: Young children (2-4 years) were detected to have significantly greater exposure to ETS than older children (5-11 years) and in the younger group the effect seemed to be from the mother's smoking much more than the father's, with other persons contributing negligible amounts. This suggests an obvious strategy for prevention of exposure to ETS in young children.