Orofacial clefts in the newborn and environmental and occupational parental exposures: a case-control study in Rio de Janeiro, Brazil

OBJECTIVES: to evaluate risk factors involving environmental and occupational parental exposures associated with occurrence of orofacial clefts in a group of Brazilian children. METHODS: a secondary base case-control study was conducted with 274 cases of cleft lip with or without cleft palate (CL±P) and cleft palate only, with 548 controls (1:2). The authors analyzed residential proximity to industrial areas, exposure to commercial insecticides, agricultural pesticides, and vector control spraying, as well as various occupational exposures. The results were obtained by conditional regression analysis. RESULTS: proximity to industrial installations as a risk factor (OR = 3,32; 95%CI: 2,18-5,05) for all orofacial clefts, as well as the combined use of household insecticides and urban vector control pesticide spraying (OR = 5,73; 95%CI: 2,51-11,28). A group of maternal occupations heavily associated with orofacial clefts was domestic services (OR = 2,89; 95%CI: 1,76-4,86). CONCLUSIONS: solvents are frequently associated with CL ± P and that they are contained in numerous industrial products and household cleaning products, the results pertaining to occupational exposure become plausible. Other associations such as the routine use of domestic insecticides require further specific research for confirmation of the hypothesis.