Childhood Correlates of Blood Lead Levels in India

Abstract

P-684 Introduction: Lead exposure has previously been associated with intellectual impairment in children in a number of international studies. In India, it has been reported that nearly half of the children have elevated blood lead levels (BLLs). However, little is known about risk factors for these elevated BLLs. Methods: We conducted a retrospective cross-sectional analysis of data from the Indian National Family Health Survey, a population-based study conducted in 1998–99. We assessed potential correlates of BLLs in 1,081 children who were <3 years of age and living in Mumbai or Delhi. We examined factors such as age, sex, religion, caste, mother's education, standard of living, breast feeding, and weight/height percentile. Results: Most children (76%) had BLLs between 5 and 20 μg/dL. Age, standard of living, weight/height percentile and total number of children ever born to mother were significantly associated with BLLs (log transformed) in multivariate regression models. As compared with children ≤3 months of age, 4–11 and 12–23 month olds had 84% and 146% higher BLLs, respectively (p<0.001). A low standard of living correlated with a 32.3% increase in BLLs (p=0.02). Children >95 percentile for their weight/height had 31% (p=0.03) higher BLLs as compared with those who were <5 percentile for their weight/height. Children from the same immediate family had highly correlated BLLs (correlation coefficient=0.48). Discussion and Conclusions: Our study found that increasing age, a lower standard of living index, >95 weight/height percentile, and higher total number of children ever born to mother were correlated with elevated BLLs in children <3 years of age in Mumbai and Delhi. The correlation between >95 percentile weight/height and higher BLL may reflect an impact of lead exposure on body habitus. Since, lead pollution is a public health issue of concern, the demonstration of factors correlated with BLLs in Indian children may aid in prioritization of children for lead screening and also in studying correctable factors. Although, progress has recently been made by phasing out leaded gasoline in India, exposure from many other sources (including the entrainment of lead oxide from combusted leaded gasoline into dust, water, and the food system) is likely to continue for many years to come. Further efforts to control lead pollution, especially in populations at high risk, should be considered.