Impact of the COVID-19 Pandemic on Blood Lead Testing in Children in the United States.

The study objective was to evaluate the impact of the coronavirus disease (COVID-19) pandemic on pediatric blood lead testing in the United States. Clinical laboratory pediatric (ages <6 years) blood lead level (BLL) tests performed by Quest Diagnostics, January 2019-March 2022, were analyzed. Patients were categorized by age, by sex, and, through matching by ZIP code with US Census data, for race, ethnicity, pre-1950 housing, and poverty estimates. Over 2.8 million results from children (<6 years old) from all 50 states and the District of Columbia were included. Compared to March-May 2019, BLL testing was lower by 53.6% in March-May 2020 and lower by 14.6% in March-May 2021. Testing rebounded more for children in predominantly White non-Hispanic communities and among children living in communities, based on ZIP codes, with the least pre-1950 housing stock and lowest poverty rates. The proportion of children with BLL at or above the United States Centers for Disease Control and Prevention reference values of 3.5 and 5.0 µg/dL fell by 19% and 24%, respectively, in 2021 versus 2019. In conclusion, pediatric BLL testing has rebounded from sharp declines during the early pandemic period but unevenly. Declines in the proportion of children with elevated BLL should be interpreted with caution, as testing rebounds were less robust among communities with the highest risk of lead poisoning, notably communities with the oldest housing stock and higher poverty rates. More public health efforts are needed to address lead toxicity throughout the United States, especially in communities that did not experience a full rebound subsequent to the early COVID-19 pandemic period.