Mind, DisruptedPhoto
AboutThe ParticipantsThe ProblemFindingsToxic ChemicalsPolicy RecommendationsThe ScienceResources

People with Learning
and Developmental Disabilities

stairsSome populations are especially vulnerable to the potential health effects of toxic chemical exposures, including people with learning and developmental disabilities.

Exposure to neurotoxic chemicals may exacerbate existing learning and developmental disabilities. For example, every 1 µg/dL (microgram per deciliter) increase in average lifetime blood lead level (while still under the CDC’s 10 µg/dL level of concern of concern) results in an average IQ decrease of 1.37 points.82 That may sound like a negligible effect. But a one-point IQ increase has been estimated to translate into a 1.8–2.4% increase in lifetime earnings.83 For someone with intellectual disability, a handful of IQ points can mean the difference between being able to hold a job and live independently or not.

Beth Terrill explains, “Knowing that these chemicals are in us helps inform other people about toxic chemicals so they can then choose more carefully what to do and what to eat. I get headaches when I’m around paint or other chemicals in the house. I also get stomach aches. I also worry about being around chemicals that are used to kill bugs.”

Infants and young children with developmental disabilities may spend more time in the crawling stage of development than those without such disabilities, thus spending a greater portion of their early childhood exposed to dirt and dust on the floor. More time on the floor could, in turn, translate to higher intake of toxic chemicals that migrate from objects to household dust. A 2009 study estimated that ingestion and dermal absorption of household dust accounts for 56–77% of total intake of PBDEs (flame retardants) in toddlers, children, and adults. The same study calculated the daily estimated exposure to PBDEs of toddlers to be 13.3 nanograms per kilogram of body weight per day — over four times greater than the daily estimated exposure of adults.84

Also, children and adults with developmental disabilities may be more prone to pica behaviors (ingesting non-food items at developmentally inappropriate ages), which can lead to lead poisoning85 and likely increase other toxic chemical exposures.

Because of difficulty in reading or interpreting warnings about toxic chemical exposures, some adults with learning and developmental disabilities may be more prone to toxic exposures. For example, they may find it difficult to decipher labels listing toxic ingredients or understand cautionary notices about fish consumption and mercury.

“How can I choose safe products when companies don’t tell me what ingredients are in the products I like to use,” asks Joe Meadours. “I want to protect my health but companies make this difficult. Old ways are hard to break, but really, why can’t products I use be free from harmful chemicals?”

“No one gets a pass on these exposures,” said Judy Robinson. “Yet the consequences of chemical exposure for one person may be very different than for another. I remember speaking at a press conference of a group of researchers reacting to news of high lead levels in children’s toys. One of the other presenters at the event made what seemed like an innocent joke about how if his blood lead levels had been lower when he was growing up he might have gone to Harvard instead of Yale (or was it Yale instead of Harvard?). Everyone laughed. But it was a hard joke for me to hear. As a mother of a child with learning and developmental disabilities I come from a community of people who understand that for some individuals the difference of a few IQ points determines more than which Ivy League college you go to. It represents the difference between whether you will hold a job or not; between whether you will be able to manage a bank account or not; between whether you will live independently or will for the rest of your life be reliant on family, friends, community supports, and the federal government to provide for your life long care.”

In this context, it is important to note that minority populations and people with low socioeconomic status are more likely to be exposed to some toxic chemicals than non-minorities and those of higher socioeconomic status.

A nationally representative, random survey of U.S. housing units found that 35% of low-income housing posed significant lead-based paint hazards, compared to 19% of higher-income housing.86 Another national-level study — a follow-up to the United Church of Christ’s groundbreaking 1987 “Toxic Wastes and Race” report — found that, on average, people of color constitute the majority (56%) of residents in “host areas” (areas within three kilometers of commercial hazardous waste facilities), but constitute a significantly smaller percentage (30%) of residents in non-host areas. The report also found that poverty rates in host areas are 1.5 times greater than those in non-host areas.87