Modification of the effects of nitrogen dioxide and sulfur dioxide on congenital limb defects by meteorological conditions

AbstractSTUDY QUESTIONCan meteorological conditions modify the associations between NO2 and SO2 exposure and congenital limb defects (CLDs) during the first trimester of pregnancy?SUMMARY ANSWERIncreases in NO2 and SO2 exposure were consistently associated with higher risks of CLDs during the first trimester of pregnancy; both low- and high-temperature exposure and high air humidity act synergistically with the two air pollutants on CLDs.WHAT IS KNOWN ALREADYAnimal studies have indicated air pollutants are associated with CLDs, but corresponding epidemiological studies are limited with equivocal conclusions. Meteorological conditions are closely connected to the generation, diffusion, distribution and even chemical toxicity of air pollutants.STUDY DESIGN, SIZE, DURATIONThis case –control study included 972 cases of CLDs and 9720 controls in Changsha, China during 2015–2018.PARTICIPANTS/MATERIALS, SETTING, METHODSCases from the hospital based monitoring system for birth defects (including polydactyly, syndactyly, limb shortening, and clubfoot) and healthy controls from the electronic medical records system were studied. Complete data on daily average NO2 and SO2 concentrations and meteorological variables were obtained from local monitoring stations to estimate monthly individual exposures during the first trimester of pregnancy, using the nearest monitoring station approach for NO2 and SO2 concentrations, and the city-wide average approach for temperature and relative hum...
Source: Human Reproduction - Category: Reproduction Medicine Source Type: research