|
| Toxicant | Sources of exposure | Study findings |
|
| Flame retardant chemicals | Polyurethane foam in mattresses, furniture, carpet padding, car seats, and so forth (particularly those made before 2005) | Cord blood flame retardant levels linked to impaired mental and physical function at 1, 3, and 6 years of age [16] |
| Prenatal PBDE exposure linked to decreased IQ and increased hyperactivity at 5 years of age [169] |
| Dose-dependent inverse relationship between serum levels of PBDEs and thyroid stimulating hormone in pregnant women [170] |
|
| Bisphenol A | Hard plastics used in food storage, leaching from lining of canned food and drink, water coolers, dental sealants, contact lenses | Prenatal exposure to bisphenol A associated with persistent wheezing in offspring [171] |
| Elevated maternal serum BPA at delivery associated with increased risk of low birth weight babies [172] |
| Twofold increase in first trimester maternal serum BPA associated with 55 g less birth weight in offspring [173] |
|
| Phthalates | Plasticizer in soft plastics, fragrances, perfume, cosmetics, paint, flooring | Prenatal phthalate exposure linked to 70% increased risk of asthma [174] |
| Maternal phthalate levels linked to decreased IQ in offspring at 7 years of age [175] |
| Elevated phthalate metabolite urine concentration associated with increased risk of spontaneous abortion in dose-dependent fashion [176] |
| Elevated phthalate metabolites in maternal urine in early pregnancy associated with decreased anogenital distance in male offspring [177] |
|
| Pesticides, insecticides, herbicides | Nearby farms, parks, cemeteries, golf courses; pesticide residue on foods Spraying on lawns of patient and neighbours | Pregnant women living within 1.5 miles of an area sprayed with pesticides and insecticides associated with 60% increase in autism spectrum disorder [178] |
| Agricultural pesticide exposure associated with 2-fold increase in odds of developing gestational diabetes [179] |
| Every standard deviation increase in chlorpyrifos (a common insecticide) exposure corresponded to 1.4% decline in IQ and 2.8% decline in working memory in 7-year-old children [180] |
| In a meta-analysis, OR was 2.1–2.4 for childhood leukemia with prenatal maternal occupational pesticide exposure; risk also elevated with prenatal maternal occupational exposure to insecticides (OR 2.72) or herbicides (OR 3.62) [181] |
|
| Solvents | Occupational exposures (cleaners, nurses, hairdressers, chemists) Inhalational exposure from paints, cleaning products, cosmetics, air pollution from nearby industry | Parental exposure to solvents associated with a nearly 3-fold increased risk of autism spectrum disorder in offspring [182] |
| Solvent exposure in early pregnancy associated with dose-dependent increased risk of birth defects, particularly oral clefts, urinary tract malformations, and male genital malformations [183] |
| Occupational exposure to solvents in first trimester of pregnancy associated with 13-fold increased risk of major malformations [28] |
| From 3-month preconception through to the end of breast feeding period, parents of children with autism are more likely to have been exposed to lacquer, varnish, xylene, asphalt, and other solvents compared to parents of controls [184] |
|
| Air pollution | Benzene and other volatile gases from car exhaust, petroleum derived volatile chemicals from nearby industry, (oil refineries, car factories/repair shops), and so forth | Childhood cancers geographically associated with birth address of mother when proximate to specific industries and airborne exposures [31, 185] |
| Exposure to ozone and fine particulate matter associated with increased risk of gestational hypertension and preterm delivery [186] |
| Increased risk of low birth weight and premature infants with increasing exposure to sulfur dioxide and measured levels of total suspended particles [187] |
| 25–51% increased rate of Hodgkin’s lymphoma in offspring with maternal high exposure to traffic-related air pollution in pregnancy [188] |
| Maternal residence in pregnancy proximate to a freeway more common in mothers of children with autism than mothers of controls [189] |
|
| Home renovation | VOCs from flooring and painting; flame retardants in furniture and carpets; formaldehyde from particleboard; and so forth | Home renovation or redecoration within past 12 months (including flooring, painting, and new furniture) associated with increased risk of wheezing, allergy, and asthma symptoms in offspring [190]
New furniture in the home in the year before birth associated with significant increase in wheezing, allergic rhinitis, and eczema in offspring [191] |
|
| Heavy metals | Lead: old, flaking lead paint, cosmetics, food contamination from elevated soil levels, old water pipes, and so forth | Maternal exposure to levels of lead as low as 5 μg/dL associated with lower developmental functioning in newborns, particularly if exposed in first trimester [192] |
| Maternal lead exposure related to significant decrease in Mental Development Index [193] |
| Mercury: dental amalgams, dietary consumption (seafood), and so forth | Significant relationship between fish consumption in pregnancy and mercury levels in mothers and newborn infants [194] |
| 6- and 7-year olds scholastic and psychological test scores significantly associated with mercury levels in mothers during their pregnancy [195] |
| 7-year-old children neurophysiological testing demonstrated association between elevated maternal mercury level in pregnancy and lower testing scores [196] |
| For every 1000 lb of environmentally released mercury, a corresponding geographical 61% increase in autism rates was found [197] |
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