חשיפה סביבתית לרעלים באויר ואוטיזם- SAN FRANC
הצלבת מידע בין ילדים עם אוטיזם ואויר מזוהם במתכות ורעלים: From Environmental Health Perspectives Autism Spectrum Disorders in Relation to Distribution of Hazardous Air Pollutants in the San Francisco Bay Area Gayle C. Windham; Lixia Zhang; Robert Gunier; Lisa A. Croen; Judith K. Grether Authors and Disclosures Published: 12/12/2006 Print This processing.... Abstract and Introduction Materials and Methods Results Discussion Conclusions References Information from Industry Assess clinically focused product information on Medscape. Click Here for Product Infosites – Information from Industry. Abstract and Introduction Abstract Objective: To explore possible associations between autism spectrum disorders (ASD) and environmental exposures, we linked the California autism surveillance system to estimated hazardous air pollutant (HAP) concentrations compiled by the U.S. Environmental Protection Agency. Methods: Subjects included 284 children with ASD and 657 controls, born in 1994 in the San Francisco Bay area. We assigned exposure level by census tract of birth residence for 19 chemicals we identified as potential neurotoxicants, developmental toxicants, and/or endocrine disruptors from the 1996 HAPs database. Because concentrations of many of these were highly correlated, we combined the chemicals into mechanistic and structural groups, calculating summary index scores. We calculated ASD risk in the upper quartiles of these group scores or individual chemical concentrations compared with below the median, adjusting for demographic factors. Results: The adjusted odds ratios (AORs) were elevated by 50% in the top quartile of chlorinated solvents and heavy metals [95% confidence intervals (CIs) , 1.1-2.1], but not for aromatic solvents. Adjusting for these three groups simultaneously led to decreased risks for the solvents and increased risk for metals (AORs for metals: fourth quartile = 1.7 ; 95% CI, 1.0-3.0 ; third quartile = 1.95 ; 95% CI, 1.2-3.1) . The individual compounds that contributed most to these associations included mercury, cadmium, nickel, trichloroethylene, and vinyl chloride. Conclusions: Our results suggest a potential association between autism and estimated metal concentrations, and possibly solvents, in ambient air around the birth residence, requiring confirmation and more refined exposure assessment in future studies. Introduction Autism is a serious neurodevelopmental disorder characterized by impairments in social interaction, verbal and nonverbal communication, and other restricted behaviors. The number of children reported with autistic spectrum disorders (ASDs) has increased dramatically during the last 10 years, but it is difficult to determine how much of this increase represents actual incidence and how much may be due to increased awareness and diagnosis; the causes remain largely unknown (Barbaresi et al. 2005; Croen et al. 2002a, 2002b; Newschaffer et al. 2005; Yeargin-Allsopp et al. 2003). Autism is believed to result from disruption of normal neurobiologic mechanisms primarily in the prenatal period and is widely recognized to have a strong genetic component, probably involving multiple gene loci. Nongenetic factors are also likely involved and may explain some of the increased prevalence. Medications such as thalidomide and valproic acid in utero have been linked to cases of autism (Moore et al. 2000; Rodier and Hyman 1998; Stromland et al. 1994). Maternal smoking during pregnancy has also been associated (Hultman et al. 2002), and there are case reports of children with both fetal alcohol syndrome and autism (Aronson et al. 1997). Other exogenous exposures known or suspected to interfere with neurodevelopment may also play a role in ASD etiology. Heavy metals such as lead and mercury have been relatively well studied in relation to impaired neurodevelopment (Bellinger et al. 1984; Burbacher et al. 1990; Grandjean et al. 1997; Mendola et al. 2002), but few studies have examined associations with autism. Compounds that interfere with the endocrine system may also play a role, particularly those affecting maternal thyroid hormones, which are critical to fetal brain development (Brouwer et al. 1998; London and Etzel 2000). In addition, prenatal exposure to some solvents has recently been associated with developmental delays in offspring (Laslo-Baker et al. 2004). Hazardous air pollutants (HAPs), as defined by the Clean Air Act Amendments of 1990, are compounds associated with adverse health outcomes such as cancer and neurologic and developmental effects [U.S. Environmental Protection Agency (EPA) 1994]. For the most part, monitoring data on these pollutants have been limited. Therefore, the U.S. EPA developed a nationwide database with modeled annual average concentrations of HAPs (Rosenbaum et al. 1999). The estimated concentrations for several compounds, including some metals, exceed the health-based benchmark concentrations for chronic toxicity in both California and the United States (Morello-Frosch et al. 2000; Woodruff et al. 1998). To track prevalence rates of autism and to provide descriptive data on the condition, surveillance has been instituted in several states. Coordinated by the Centers for Disease Control and Prevention (CDC), these programs have been organized into Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) and Autism and Developmental Disorders Monitoring (Rice et al. 2004; Yeargin-Allsopp et al. 2003). In six counties in the San Francisco Bay area, we are conducting multisource surveillance to ascertain ASD cases identified from clinical sources as well as from the Department of Developmental Services (DDS), which provides services for California residents with a variety of eligible developmental disabilities. We conducted an exploratory case-control analysis linking our autism surveillance data to HAPs data for the San Francisco Bay area to examine the potential role of ambient chemical exposures during pregnancy or early life in ASD etiology.
הצלבת מידע בין ילדים עם אוטיזם ואויר מזוהם במתכות ורעלים: From Environmental Health Perspectives Autism Spectrum Disorders in Relation to Distribution of Hazardous Air Pollutants in the San Francisco Bay Area Gayle C. Windham; Lixia Zhang; Robert Gunier; Lisa A. Croen; Judith K. Grether Authors and Disclosures Published: 12/12/2006 Print This processing.... Abstract and Introduction Materials and Methods Results Discussion Conclusions References Information from Industry Assess clinically focused product information on Medscape. Click Here for Product Infosites – Information from Industry. Abstract and Introduction Abstract Objective: To explore possible associations between autism spectrum disorders (ASD) and environmental exposures, we linked the California autism surveillance system to estimated hazardous air pollutant (HAP) concentrations compiled by the U.S. Environmental Protection Agency. Methods: Subjects included 284 children with ASD and 657 controls, born in 1994 in the San Francisco Bay area. We assigned exposure level by census tract of birth residence for 19 chemicals we identified as potential neurotoxicants, developmental toxicants, and/or endocrine disruptors from the 1996 HAPs database. Because concentrations of many of these were highly correlated, we combined the chemicals into mechanistic and structural groups, calculating summary index scores. We calculated ASD risk in the upper quartiles of these group scores or individual chemical concentrations compared with below the median, adjusting for demographic factors. Results: The adjusted odds ratios (AORs) were elevated by 50% in the top quartile of chlorinated solvents and heavy metals [95% confidence intervals (CIs) , 1.1-2.1], but not for aromatic solvents. Adjusting for these three groups simultaneously led to decreased risks for the solvents and increased risk for metals (AORs for metals: fourth quartile = 1.7 ; 95% CI, 1.0-3.0 ; third quartile = 1.95 ; 95% CI, 1.2-3.1) . The individual compounds that contributed most to these associations included mercury, cadmium, nickel, trichloroethylene, and vinyl chloride. Conclusions: Our results suggest a potential association between autism and estimated metal concentrations, and possibly solvents, in ambient air around the birth residence, requiring confirmation and more refined exposure assessment in future studies. Introduction Autism is a serious neurodevelopmental disorder characterized by impairments in social interaction, verbal and nonverbal communication, and other restricted behaviors. The number of children reported with autistic spectrum disorders (ASDs) has increased dramatically during the last 10 years, but it is difficult to determine how much of this increase represents actual incidence and how much may be due to increased awareness and diagnosis; the causes remain largely unknown (Barbaresi et al. 2005; Croen et al. 2002a, 2002b; Newschaffer et al. 2005; Yeargin-Allsopp et al. 2003). Autism is believed to result from disruption of normal neurobiologic mechanisms primarily in the prenatal period and is widely recognized to have a strong genetic component, probably involving multiple gene loci. Nongenetic factors are also likely involved and may explain some of the increased prevalence. Medications such as thalidomide and valproic acid in utero have been linked to cases of autism (Moore et al. 2000; Rodier and Hyman 1998; Stromland et al. 1994). Maternal smoking during pregnancy has also been associated (Hultman et al. 2002), and there are case reports of children with both fetal alcohol syndrome and autism (Aronson et al. 1997). Other exogenous exposures known or suspected to interfere with neurodevelopment may also play a role in ASD etiology. Heavy metals such as lead and mercury have been relatively well studied in relation to impaired neurodevelopment (Bellinger et al. 1984; Burbacher et al. 1990; Grandjean et al. 1997; Mendola et al. 2002), but few studies have examined associations with autism. Compounds that interfere with the endocrine system may also play a role, particularly those affecting maternal thyroid hormones, which are critical to fetal brain development (Brouwer et al. 1998; London and Etzel 2000). In addition, prenatal exposure to some solvents has recently been associated with developmental delays in offspring (Laslo-Baker et al. 2004). Hazardous air pollutants (HAPs), as defined by the Clean Air Act Amendments of 1990, are compounds associated with adverse health outcomes such as cancer and neurologic and developmental effects [U.S. Environmental Protection Agency (EPA) 1994]. For the most part, monitoring data on these pollutants have been limited. Therefore, the U.S. EPA developed a nationwide database with modeled annual average concentrations of HAPs (Rosenbaum et al. 1999). The estimated concentrations for several compounds, including some metals, exceed the health-based benchmark concentrations for chronic toxicity in both California and the United States (Morello-Frosch et al. 2000; Woodruff et al. 1998). To track prevalence rates of autism and to provide descriptive data on the condition, surveillance has been instituted in several states. Coordinated by the Centers for Disease Control and Prevention (CDC), these programs have been organized into Centers for Autism and Developmental Disabilities Research and Epidemiology (CADDRE) and Autism and Developmental Disorders Monitoring (Rice et al. 2004; Yeargin-Allsopp et al. 2003). In six counties in the San Francisco Bay area, we are conducting multisource surveillance to ascertain ASD cases identified from clinical sources as well as from the Department of Developmental Services (DDS), which provides services for California residents with a variety of eligible developmental disabilities. We conducted an exploratory case-control analysis linking our autism surveillance data to HAPs data for the San Francisco Bay area to examine the potential role of ambient chemical exposures during pregnancy or early life in ASD etiology.