B. About the same as it has been for the past 50 years

C. At natural levels thanks to recent regulation

Lead exposure has a harmful effect on childhood IQ and can contribute to health issues such as ADHD and conduct disorders. Depending on exposure level, the potential clinical and medical effects of lead exposure are vast and even in asymptomatic children can include virtually every system in the body. Therefore, safe blood levels in children are non-existent.

 from the Advisory Committee on Childhood Lead Poisoning Prevention of the CDC were issued in 2012.

 The term “level of concern” was removed, and the reference value for clinical intervention was lowered from 10 µg/dL to 5 µg/dL. At the time the cutoff was in the 95th percentile in the US population, which implies that the standard level could be lowered again as population exposure levels decline.

Because clinical options for low-level lead exposure are limited and neurodevelopmental effects may be irreversible, the CDC’s primary focus is now on eliminating lead exposure entirely via attention to older homes with lead-based paint, rather than on screening of blood lead levels. Thus, universal screening has been abandoned and replaced by targeted screening of at-risk children (eg, Medicaid recipients, immigrants).

Understanding the Link Between Lead Toxicity and ADHD

1. Advisory Committee on Childhood Lead Poisoning Prevention of the Centers for Disease Control and Prevention. Low level lead exposure harms children: a renewed call for primary prevention. 2012. 