Residential Proximity to Freeways and Autism in the CHARGE Study

Abstract

BackgroundLittle is known about environmental causes and contributing factors for autism. Basic science and epidemiologic research suggest that oxidative stress and inflammation may play a role in disease development. Traffic-related air pollution, a common exposure with established effects on these pathways, contains substances found to have adverse prenatal effects.ObjectivesWe examined the association between autism and proximity of residence to freeways and major roadways during pregnancy and near the time of delivery, as a surrogate for air pollution exposure.MethodsData were from 304 autism cases and 259 typically developing controls enrolled in the Childhood Autism Risks from Genetics and the Environment (CHARGE) study. The mother’s address recorded on the birth certificate and trimester-specific addresses derived from a residential history obtained by questionnaire were geocoded, and measures of distance to freeways and major roads were calculated using ArcGIS software. Logistic regression models compared residential proximity to freeways and major roads for autism cases and typically developing controls.ResultsAdjusting for sociodemographic factors and maternal smoking, maternal residence at the time of delivery was more likely be near a freeway (≤ 309 m) for cases than for controls [odds ratio (OR) = 1.86; 95% confidence interval (CI), 1.04–3.45]. Autism was also associated with residential proximity to a freeway during the third trimester (OR = 2.22; CI, 1.16–4.42). After adjustment for socioeconomic and sociodemographic characteristics, these associations were unchanged. Living near other major roads at birth was not associated with autism.ConclusionsLiving near a freeway was associated with autism. Examination of associations with measured air pollutants is needed.

Glutamatergic neurons in rodent models respond to nanoscale particulate urban air pollutants in vivo and in vitro

“…The impair ment of neurite outgrowth by nPM is consistent with epidemiological evidence of developmental effects of air pollution in children (Perera et al 2009;Suglia et al 2008), which include an association with autism (Volk et al 2010). The interaction of nPM with glutamatergic (NMDA) excito toxicity suggests that cerebral ischemia, which also involves glutamatergic excito toxicity, could be exacerbated by nPM.…”

“…Cognitive impairments of school-age children have been associated with exposure to black carbon (BC), a marker for vehicle-derived PM (Suglia et al 2008). Also, a prospective study of children showed associations of lower IQ with prenatal exposure to vehicle-derived polycyclic aromatic hydrocarbons (PAHs) (Perera et al 2009), and autism prevalence was associated with residential proximity at birth to urban freeways (Volk et al 2010). Rodent models also show varying memory impairment after exposure to ozone (Avila-Costa et al 1999;Dorado-Martinez et al 2001;Guerrero et al 1999;Rivas-Arancibia et al 2010) and vehiclederived air pollutants (Zanchi et al 2010).…”

Exposure to Air Pollution From Traffic and Neurodevelopmental Disorders in Swedish Twins

“…Windham et al (2006) reported a positive relation between the distribution of hazardous air pollutants at birth addresses and ASD among children in California. Other studies in California found that living close to freeways and traffic-related air pollution in mother's late pregnancy or child's first year of life was associated with an increased risk for autism (Volk et al, 2011(Volk et al, , 2013. Siddique et al (2011) compared children living in the New Delhi (India) urban area with children living in rural areas and showed that ADHD was positively correlated with current PM 10 levels.…”

“…Maternal smoking correlates with socio-economic factors such as education and income (Kabir et al, 2011;Laaksonen et al, 2005) and may contribute to this association. The earlier studies (Calderon-Garciduenas et al, 2011;Guxens et al, 2012;Siddique et al, 2011;Volk et al, 2011;Vrijheid et al, 2012;Windham et al, 2006) Odds ratios and 95% confidence intervals of neurodevelopmental outcomes by residential address-based NO x (black circles) and PM 10 (black hollow diamonds) levels. The spikes represent odds ratios for outcomes of interest and cap lines indicate 95% confidence intervals.…”

Air Quality, Health and Community Action

“…The third trimester of pregnancy appears to have the strongest association with the health impact of the concentration of air pollutants on autism [66]. Living near a freeway was associated with autism [90]. Traffic sources of air pollution were significant in the study by Becerra et al [6].…”