Background on Lead Poisoning:
Childhood lead toxicity is not a problem new to science, and instead has been recognized for at least 100 years. Studies have demonstrated that asymptomatic children with higher levels of lead had lower IQ scores, more language difficulties, attention problems, and behavior disorders. Medical research has documented that exposure to lead causes neurological damage, behavioral and learning disabilities among children, and harms the ability of students to reach their full potential as adults. Exposure to lead can result in lifelong health effects, and because lead is stored in bone and released during pregnancy, exposure can result in lead poisoning of the children of individuals decades after they are exposed.
There are no safe levels of exposure to lead and there are no safe levels of lead in children’s blood. The total IQ loss in young children that is attributable to current exposures to lead still exceeds that attributable to many pediatric conditions, including brain tumors and traumatic brain injury. The National Toxicology Program concluded that blood lead concentrations <5 μg/dL are linked with intellectual deficits, diminished academic abilities, and elevated rates of attention-related behavior problems and problem behaviors such as attention-deficit/hyperactivity disorder and conduct disorder.
The Centers for Disease Control reports that children are exposed to lead from different sources (such as paint, solder, and consumer products such as toys, food items and cosmetics) and through different pathways (such as air, food, water, dust, and soil). There are numerous sources of lead that can be found in the built environment, including lead chips, grit and dust from lead paint and its removal, contaminated water, polluted soils and air emissions. Lead exposure can also result from certain occupational and recreational activities of individuals and their families, including art pigments, marksmanship/shooting firearms, and consuming game.
In October 2021, the CDC lowered the Blood Lead Reference Value (BLRV) for lead exposure to 3.5 µg/dL. The purpose of the CDC’s BLRV is to guide public health agencies in establishing thresholds for defining elevated blood lead levels (i.e. lead poisoning), establishing medical and environmental follow-up criteria, and prioritizing resources and communities for primary prevention measures. The BLRV has been lowered over time as new clinical and scientific evidence has become available. In 1985 the threshold was 25 µg/dL, which was lowered in 1991 to 10 µg/dL, and in 2012 it was lowered to 5 µg/dL. Most recently, in 2021, the threshold was set at 3.5 µg/dL.
