Socio-economic status, race and gender—these are variables researchers use when studying gaps in test scores for children in impoverished communities. But researchers are now examining another element: lead toxicity. A recently published National Bureau of Economics Research working paper suggests that a decrease in the average level of lead in a preschooler’s blood reduces the probability of that child being substantially below proficient in reading by the third grade.

The study looked at children in Rhode Island born between 1997 and 2005 who lived in homes where lead was remediated or mitigated. Lead can be found in paint, soil, plumbing, or other sources often found in old homes. Impoverished and minority children tend to show higher levels of lead exposure mainly due to a history of class and racial segregation where families live in pre-1978 housing. Older homes are prone to exposure to lead and other toxins.  The study suggests that lead poisoning may be one of the reasons for gaps in test scores for children from different socioeconomic groups. It also found that by third grade, test scores rose for all children in the study, regardless of demographic group, while the fraction scoring substantially below proficient declined.

Some states, like New York, require doctors to test children for lead at the age of 1 year and again at age 2 years. According to the New York State Department of Health, lead poisoning can occur when children lick, swallow, or breathe in dust from old lead paint. If paint peels, cracks, or is worn down, the chips and dust from the old lead paint can spread onto floors, windowsills and all around the home. Lead paint dust can then get onto children’s hands and toys, and into their mouths.

An article in Ohio’s focused on the racial inequality found with black children and high lead levels:

From 1999 to 2004, black children nationally were 1.6 times more likely to test positive for lead in their blood than were white children, according to the Centers for Disease Control and Prevention. Black children were nearly three times more likely to have highly elevated blood-lead levels. In Cuyahoga County, it’s neighborhoods with majority black populations that have the highest rates of lead poisoning.

The article attributes a 1930s federal housing policy that pushed poor people to specific neighborhoods by outlining areas “deemed unsafe for home loans because of their high population of foreign-born or black residents, effectively barred these residents from home-ownership and the ability to build wealth…” In many states lead was banned in 1978. But older homes in impoverished communities were rarely updated to meet health and safety standards.

In Illinois, another study found that early childhood exposure to lead is associated with poorer achievement on standardized reading and math tests in the third grade, even at very low exposure levels.

Another study in Massachusetts found lead continues appearing in children’s blood. The Boston Herald reported that 5,000 children in Massachusetts tested positive for what the US Centers for Disease Control and Prevention considers to be elevated lead levels. The article features a family from the Grove Hall neighborhood—an impoverished area of Hispanic and Black residents  —who live in a century-old Dorchester home, where the blood lead level of a young boy tripled in a year.

Preventing lead exposure in early childhood is critical to improving school performance.

Dr. Harold Farber, Pediatric Pulmonologist with Texas Children’s Hospital blogged  about what can be done for kids who test positive for lead:

“For kids with low levels of lead, we can treat them by having them eat foods rich in iron, calcium and vitamin C (which help rid the body of lead) and by reducing the source of lead in the child’s environment. For kids with high levels, we’ll facilitate an environmental investigation, and those with very high levels will be referred to our excellent lead poisoning specialists.”

It’s now widely accepted that lead is a neurotoxin associated with reduction in intellectual abilities, learning deficits, and neurobehavioral disorders in children.

We need to make sure parents understand the importance of testing children and being aware of environmental factors. Even at small amounts of lead exposure, the toxicity can have massive impact on children.