Effects of Lead
LEAD LEVEL (THERE IS NO SAFE LEVEL)
According to the Centers for Disease Control and Prevention (CDC), no blood lead level (BLL) should be considered safe (2015). Overall, we have not met the goal set for Healthy People 2020 to eliminate blood lead levels of 10 µg/dL or higher has not been met (CDC, 2015). In 2010, the CDC deemed the upper limit of blood lead levels to be 5 µg/dL; therefore, anything over 5 µg/dL requires intervention.
When a level between 5-9 µg/dL is found, the lead level should be confirmed with a venous sample test within 1-3 months (if initial stick is from a capillary sample). A referral to the child's primary care provider, local clinic, or the Lucas County Health Department can be made for follow-up testing. Levels of lead should continue to be drawn every 3 months for the first year, then every 6-9 months until the level is below 5 µg/dL. A level of 10-44 µg/dL should be confirmed by venous sample within 1 month (ODH, 2015).
EFFECTS OF ELEVATED LEAD
There is compelling evidence that elevated lead levels can have serious consequences like:
- Decreased IQ
- Decreased attention span
- Lower executive functioning
- Poor spatial-visual skills
- Behavioral challenges
- Speech and language delay
- Impaired fine and gross motor skills (CDC, 2015)
Children and pregnant women tend to absorb lead at a higher rate; children absorb around 50% of ingested lead, whereas adults absorb about 10% (Manahan, Brockman, & Woods, 2007). Calcium and iron are minerals that can affect lead levels. A deficiency in either can cause increased absorption of lead. Once lead is absorbed into the body, it deposits in blood, bone, and tissue (Manahan et al., 2007). Lead can interrupt brain development. Normal brain development occurs in a timed sequence. Any interruption of this sequence can cause permanent disabilities. (Manahan et al., 2007).
Multiple studies have shown elevated lead levels negatively impact educational performance and testing outcomes even when mildly elevated (CDC, 2015).
LITERATURE ON Lead AND CHILDREN |
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Outcome Blood Lead Levels |
Educational Impact | Size of Study | Location of Study |
≤ 3 µg/dL | Decreased end of grade test scores | More than 57,000 children | North Carolina (Miranda et al. 2009) |
4 µg/dL at 3 years of age | Increased likelihood learning disabled classification in elementary school Poorer performance on tests | More than 57,000 children 35,000 children |
North Carolina (Miranda et al. 2009) 1 Connecticut (Miranda et al. 2011) |
5 µg/dL | 30% more likely to fail third grade reading and math tests More likely to be non-proficient in math, science, and reading |
More than 48,000 children 21,000 children |
Chicago (Evens et al. unpublished data) Detroit (Zhang et aJ. 2013) |
5-9 µg/dL | Scored 4.5 points lower on reading readiness tests | 3,406 children | Rhode Island (Mclaine et al. 2013) |
≥ 10 µg/dL | Scored 10.1 points lower on reading readiness tests | 3,406 children | Rhode Island (Mclaine et al. 2013) |
10 and 19 µg/dL | Significantly lower academic performance test scores in 4th grade | More than 3,000 children | Milwaukee (Amato et al. 2012) |
≥ 25 µg/dL | $0.5 million in excess annual special education and juvenile justice costs | 279 children | Mahoning County, Ohio (Stefanak et al. 2005) |
(CDC, 2015)