NEHA October 2022 Journal of Environmental Health

8 Volume 85 • Number 3 A D VANC EME N T O F T H E SCIENCE Introduction Lead exposure can seriously a ect the health of children (World Health Organization, 2022). High levels of lead exposure can harm the brain and central nervous system of children. High levels of lead exposure can also cause coma, convulsions, and death in children. Children who survive severe lead poisoning can su er from mental deficiencies and behavioral disorders. Lead is known to a ect children’s brain development and can result in reduced IQ and behavioral changes such as short attention span and reduced educational attainment. Most importantly, these neurological and behavioral e ects of lead are irreversible (Centers for Disease Control and Prevention [CDC], 2022; Egan et al., 2021). Georgia Department of Public Health (n.d.) guidelines for blood lead screening recommend screening children who belong to high-risk groups such as families receiving Medicaid or Peach Care for Kids (i.e., health coverage for children in low-income families). The guidelines also recommend screening in 16 counties in which children are at greater risk for lead exposure. Following these guidelines, the resulting group of children to be tested for elevated blood lead levels (BLLs), however, is limited and some children with elevated BLLs might be missed. In 2012, the Centers for Disease Control and Prevention (CDC, 2021) defined a BLL of 5 µg/dL as a reference value for children <6 years. Note, this reference value was changed to a more stringent level of 3.5 µg/dL but at the time of our study the limit was 5 µg/dL. Bayesian analysis with limited beliefs about a parameter can be helpful in modeling the exposure of lead in children by suitably matching these beliefs with some known distribution. The primary objective of our study was to estimate and validate the observed number of children with BLLs of 5–9 µg/dL among children <6 years in di erent counties of Georgia, selected by region. This objective was important to investigate if screening of a limited group of children in Georgia resulted in underreporting of children with elevated BLLs. Although some studies have connected targeted screening and missed children with elevated BLLs (Roberts et al., 2017), no such research work has been found evaluating the impact of targeted screening on the rate of children <6 years with elevated BLLs in a region, especially in Georgia. Methods Data Collection We used data collected by the Healthy Homes and Lead Poisoning Prevention Program of the Georgia Department of Public Health for 2015. Child blood lead surveillance data was used, including the number of children <6 years who were tested and the number of children with BLLs of 5–9 µg/dL, by race and county. Estimates of children <6 years were available from the Georgia Governor’s O£ce of Planning and Budget (2016). Bayesian Model The variable z was used to represent the number of children <6 years with BLLs of 5–9 µg/dL in a county in Georgia. Because this event is rare, one can safely assume that z follows a statistical distribution known as Poisson distribution shown by: p(z/θ) = e–(m . θ)(m . θ)z/z! (1) Where θ is the rate of children with BLLs of 5–9 µg/dL (i.e., θ = children with BLLs of Abs t r ac t In Georgia, children in high-risk counties are at increased risk for lead exposure. Those children and others in high-risk groups, such as families receiving Medicaid and Peach Care for Kids (i.e., health coverage for children in low-income families), are screened for blood lead levels (BLLs). Such screening, however, might not include all children at high risk for having BLLs above the reference levels (≥5 µg/dL) in the state. In our study, Bayesian methods were used to estimate the predictive density of the number of children <6 years with BLLs of 5–9 µg/dL in a targeted county from each of five selected regions of Georgia. Furthermore, the estimated mean number of children with BLLs of 5–9 µg/dL in each targeted county, along with its 95% credible interval, were calculated. The model revealed likely underreporting of some children <6 years with BLLs of 5–9 µg/dL in counties of Georgia. Further investigation might help reduce underreporting and better protect children who are at risk for lead poisoning. Estimation of High Blood Lead Levels Among Children in Georgia: An Application of Bayesian Analysis Shailendra N. Banerjee, PhD National Center for Environmental Health, Centers for Disease Control and Prevention

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