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Parents of autistic children report barriers to engaging in physical activity, which may be exacerbated during subsequent pregnancies. We aimed to describe physical activity of parents caring for an autistic child, before and during a subsequent pregnancy, and to explore whether physical activity was associated with the autistic child's Social Responsiveness Scale score, a measure of autism-related traits. We used data from the Early Autism Risk Longitudinal Investigation, in which families with an autistic child were followed through a subsequent pregnancy. Mothers (n = 245) self-reported physical activity in the 3 months before conception and during pregnancy; fathers (n = 130) reported on the 6 months prior to enrollment. Approximately 40% of nonpregnant mothers and fathers and 9.3% of pregnant mothers met Physical Activity Guidelines for Americans recommendations. Most (83.5%) pregnant mothers reported no vigorous activity; after adjustment for covariates, this was more common among mothers of children with Social Responsiveness Scale T-scores >75 compared with mothers of children with lower T-scores (adjusted odds ratio (95% confidence interval) = 2.94 (1.11, 7.78)). Among parents caring for an autistic child before and during a subsequent pregnancy, physical activity was lower than recommended. Family-based interventions may be necessary to help support physical activity levels.

To compare gastrointestinal (GI) problems among children with: (1) autism spectrum disorder (ASD), (2) developmental delay (DD) and (3) typical development (TD), GI symptom frequencies were obtained for 960 children from the CHildhood Autism Risks from Genetics and Environment (CHARGE) study. We also examined scores on five Aberrant Behavior Checklist (ABC) subscales comparing ASD children with high versus low frequency GI symptoms. Compared to TD children, those with ASD [aOR 7.92 (4.89-12.85)] and DD [aOR 4.55 (2.51-8.24)] were more likely to have at least one frequent GI symptom. Restricting to ASD children, those with frequent abdominal pain, gaseousness, diarrhea, constipation or pain on stooling scored worse on irritability, social withdrawal, stereotypy, and hyperactivity compared with children having no frequent GI symptoms. Frequent GI problems affect young children with ASD and DD more commonly than those with TD. Maladaptive behaviors correlate with GI problems, suggesting these comorbidities require attention.

Objectives: To compare differences in autism between Hispanic and non-Hispanics. We also examined the relationship between multiple language exposure and language function and scores of children. Methods: The Childhood Autism Risks from Genetics and the Environment (CHARGE) study is an ongoing population-based case-control study with children sampled (n = 1061) from three strata: those with autism (AU) or autism spectrum disorder (ASD); developmental delay (DD); or the general population (GP). Results: Non-Hispanic cases demonstrated higher cognitive composite scores for the Mullen Scales of Early Learning (MSEL). There were significant associations between multiple language exposure and MSEL subscales for receptive language and expressive language, in both cases (AU/ASD) and TD controls, but not DD controls. Results of multivariate regression analyses suggest several predictors to be associated with lower Mullen expressive language scores including: diagnosis of ASD/AU, speaking to the child in a second language 25-50% of the time and Hispanic ethnicity; while maternal college education was associated with higher scores. Conclusion: Overall, the CHARGE Hispanic group displayed more similarities than differences compared to non-Hispanics in terms of autistic phenotypes and maladaptive & adaptive scores for cases. The relationship between multiple language use and cognitive scores warrants a closer look. (Contains 2 figures and 3 tables.)

Objective: There is clinical heterogeneity among the autism spectrum disorders (ASD). The presence of dysmorphology (minor physical anomalies; MPAs) is one possible tool for defining a clinically relevant subset in ASD. This study employs an adaptation of Miles and Hillman's (2000) classifications by using photographs to identify a subgroup with significant dysmorphology among children with ASD, typical development (TYP), and developmental delay (DD). Method: Children with ASD, DD, and TYP between 2 and 5 years old were part of the CHARGE Study. Pediatric specialists blinded to diagnostic group classified photographs based on the number of MPAs present: "dysmorphic" if greater than 3 and "nondysmorphic" if less than 3 MPAs. Results: Photographs for 324 children were included. Significantly more children with ASD were classified as dysmorphic compared to TYP children (p = 0.007). In children with ASD, seizures were more prevalent in those rated dysmorphic (p = 0.005). Frequencies were similar between ASD versus DD (p = 0.19) after removing those with known syndromes. Conclusion: Photographic assessment can be used to detect generalized dysmorphology in children who are often difficult to examine. This has clinical relevance, as children with multiple MPAs can be identified through the use of photographs and prioritized for investigation of brain abnormalities and underlying genetic disorders. (Contains 4 tables and 1 figure.)

Wildfires in the Western United States are a growing and significant source of air pollution that is eroding decades of progress in air pollution reduction. The effects on preterm birth during critical periods of pregnancy are unknown. We assessed associations between prenatal exposure to wildland fire smoke and risk of preterm birth (gestational age < 37 weeks). We assigned smoke exposure to geocoded residence at birth for all live singleton births in California conceived 2007–2018, using weekly average concentrations of particulate matter ≤ 2.5 µm (PM 2.5) attributable to wildland fires from United States Environmental Protection Agency's Community Multiscale Air Quality Model. Logistic regression yielded odds ratio (OR) for preterm birth in relation to increases in average exposure across the whole pregnancy, each trimester, and each week of pregnancy. Models adjusted for season, age, education, race/ethnicity, medical insurance, and smoking of the birthing parent. For the 5,155,026 births, higher wildland fire PM 2.5 exposure averaged across pregnancy, or any trimester, was associated with higher odds of preterm birth. The OR for an increase of 1 µg/m3 of average wildland fire PM 2.5 during pregnancy was 1.013 (95 % CI:1.008,1.017). Wildland fire PM 2.5 during most weeks of pregnancy was associated with higher odds. Strongest estimates were observed in weeks in the second and third trimesters. A 10 µg/m3 increase in average wildland fire PM 2·5 in gestational week 23 was associated with OR = 1.034; 95 % CI: 1.019, 1.049 for preterm birth. Preterm birth is sensitive to wildland fire PM 2.5 ; therefore, we must reduce exposure during pregnancy. [ABSTRACT FROM AUTHOR]

Exposure to silica has been linked to excess risk of lung cancer and nonmalignant respiratory disease mortality. In this study we estimated risk for both these outcomes in relation to occupational silica exposure as well as the reduction in risk that would result from hypothetical interventions on exposure in a cohort of exposed workers. Analyses were carried out using data from an all-male study population consisting of 2,342 California diatomaceous earth workers regularly exposed to crystalline silica and followed between 1942 and 2011. We estimated subdistribution risk for each event under the natural course and interventions of interest using the parametric g-formula to adjust for healthy-worker survivor bias. The risk ratio for lung cancer mortality, comparing an intervention in which a theoretical maximum exposure limit was set at 0.05 mg/m3 (the current US regulatory limit) with the observed exposure concentrations, was 0.86 (95% confidence interval: 0.63, 1.22). The corresponding risk ratio for nonmalignant respiratory disease mortality was 0.69 (95% confidence interval: 0.52, 0.93). Our findings suggest that risks from both outcomes would have been considerably lower if historical silica exposures in this cohort had not exceeded current regulatory limits. [ABSTRACT FROM AUTHOR]

Prolonged exposures can have complex relationships with health outcomes, as timing, duration, and intensity of exposure are all potentially relevant. Summary measures such as cumulative exposure or average intensity of exposure may not fully capture these relationships. We applied penalized and unpenalized distributed-lag nonlinear models (DLNMs) with flexible exposure-response and lag-response functions in order to examine the association between crystalline silica exposure and mortality from lung cancer and nonmalignant respiratory disease in a cohort study of 2,342 California diatomaceous earth workers followed during 1942-2011. We also assessed associations using simple measures of cumulative exposure assuming linear exposure-response and constant lag-response. Measures of association from DLNMs were generally higher than those from simpler models. Rate ratios from penalized DLNMs corresponding to average daily exposures of 0.4 mg/m3 during lag years 31-50 prior to the age of observed cases were 1.47 (95% confidence interval (CI): 0.92, 2.35) for lung cancer mortality and 1.80 (95% CI: 1.14, 2.85) for nonmalignant respiratory disease mortality. Rate ratios from the simpler models for the same exposure scenario were 1.15 (95% CI: 0.89, 1.48) and 1.23 (95% CI: 1.03, 1.46), respectively. Longitudinal cohort studies of prolonged exposures and chronic health outcomes should explore methods allowing for flexibility and nonlinearities in the exposure-lag-response. [ABSTRACT FROM AUTHOR]

BACKGROUND: Maternal folic acid (FA) protects against developmental toxicity from certain environmental chemicals. OBJECTIVE: We examined combined exposures to maternal FA and pesticides in relation to autism spectrum disorder (ASD). METHODS: Participants were California children born from 2000-2007 who were enrolled in the Childhood Autism Risks from Genetics and the Environment (CHARGE) case-control study at age 2-5 y, were clinically confirmed to have ASD (n=296) or typical development (n=220), and had information on maternal supplemental FA and pesticide exposures. Maternal supplemental FA and household pesticide product use were retrospectively collected in telephone interviews from 2003-2011. High vs. low daily FA intake was dichotomized at 800 lg (median). Mothers' addresses were linked to a statewide database of commercial applications to estimate agricultural pesticide exposure. RESULTS: High FA intake (≥800 lg) during the first pregnancy month and no known pesticide exposure was the reference group for all analyses. Compared with this group, ASD was increased in association with <800 lg FA and any indoor pesticide exposure {adjusted odds ratio [OR]=2:5 [95% confidence interval (CI): 1.3, 4.7]} compared with low FA [OR=1:2 (95% CI: 0.7, 2.2)] or indoor pesticides [OR =1:7 (95% CI: 1.1, 2.8)] alone. ORs for the combination of low FA and regular pregnancy exposure (≥6 mo) to pet pesticides or to outdoor sprays and foggers were 3.9 (95% CI: 1.4, 11.5) and 4.1 (95% CI: 1.7, 10.1), respectively. ORs for low maternal FA and agricultural pesticide exposure 3 mo before or after conception were 2.2 (95% CI: 0.7, 6.5) for chlorpyrifos, 2.3 (95% CI: 0.98, 5.3) for organophosphates, 2.1 (95% CI: 0.9, 4.8) for pyrethroids, and 1.5 (95% CI: 0.5, 4.8) for carbamates. Except for carbamates, these ORs were approximately two times greater than those for either exposure alone or for the expected ORs for combined exposures under multiplicative or additive models. CONCLUSIONS: In this study population, associations between pesticide exposures and ASD were attenuated among those with high versus low FA intake during the first month of pregnancy. Confirmatory and mechanistic studies are needed. [ABSTRACT FROM AUTHOR]

To assess validity of maternally-reported diabetes and hypertensive disorders, and reliability of BMI measurements during periconception and pregnancy compared with medical records when mothers are interviewed 2-5 years after delivery. To investigate whether reporting accuracy differed by child's case status (autism, delays, typical development). Participants were mothers of 2-5 year old children with and without neurodevelopmental disorders from the CHARGE ( CHildhood Autism Risks from Genetics and the Environment) Study who had both prenatal/delivery records and telephone interviews. Sensitivity and specificity of self-report in telephone interview was assessed by comparison with medical records; agreement was evaluated by kappa statistics. Deviations in reported BMI were evaluated with Bland-Altman plots and concordance correlation coefficient (CCC). Mothers of children with neurodevelopmental disorders (autism or developmental delay) reported metabolic conditions slightly more accurately than control mothers. For diabetes, sensitivity ranged from 73 to 87 % and specificity was ≥98 % across groups. For hypertensive disorders, sensitivity ranged from 57 to 77 % and specificity from 93 to 98 %. Reliability of BMI was high (CCC = 0.930); when grouped into BMI categories, a higher proportion of mothers of delayed children were correctly classified (κ = 0.93) compared with the autism group and controls (κ = 0.85 and κ = 0.84, respectively; P = 0.05). Multiparity was associated with higher discrepancies in BMI and misreporting of hypertensive disorders. For purposes of etiologic studies, self-reported diabetes and hypertensive disorders during periconception and pregnancy show high validity among mothers irrespective of child's case status. Recall of pre-pregnancy BMI is reliable compared with self-reported values in medical records. [ABSTRACT FROM AUTHOR]

Background: Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in many household items. Given concerns over their potential adverse health effects, we identified predictors and evaluated temporal changes of PBDE serum concentrations. Methods: PBDE serum concentrations were measured in young children (2-8 years old; N = 67), parents of young children (<55 years old; N = 90), and older adults (≥55 years old; N = 59) in California, with concurrent floor wipe samples collected in participants' homes in 2008-2009. We also measured serum concentrations one year later in a subset of children (N = 19) and parents (N = 42). Results: PBDE serum concentrations in children were significantly higher than in adults. Floor wipe concentration is a significant predictor of serum BDE-47, 99,100 and 154. Positive associations were observed between the intake frequency of canned meat and serum concentrations of BDE-47, 99 and 154, between canned meat entrees and BDE-154 and 209, as well as between tuna and white fish and BDE-153. The model with the floor wipe concentration and food intake frequencies explained up to 40% of the mean square prediction error of some congeners. Lower home values and renting (vs. owning) a home were associated with higher serum concentrations of BDE-47, 99 and 100. Serum concentrations measured one year apart were strongly correlated as expected (r = 0.70-0.97) with a slight decreasing trend. Conclusions: Floor wipe concentration, food intake frequency, and housing characteristics can explain 12-40% of the prediction error of PBDE serum concentrations. Decreasing temporal trends should be considered when characterizing long-term exposure. [ABSTRACT FROM AUTHOR]

Associations between stillbirth and 14 medical exposures during pregnancy were examined using deliveries in 1984 in 10 California counties. Cases (n = 332) were stillbirths and infant deaths within 24 h of birth. Randomly selected live births served as controls (n = 357) and were frequency matched by maternal age and county. Using questionnaire and vital statistics data, logistic regression and proportional hazards modelling were performed with adjustment for potential confounders. The most prevalent exposures were ultrasound (65% of cases, 58% of controls) and acetaminophen (45% of cases, 54% of controls). Prescription pain medication, when taken in the first 2 gestational months, was strongly associated with stillbirths due to congenital anomalies (odds ratio = 7.5, 95% confidence interval [CI] 2.3, 24.1). First and second trimester use of prescription pain or migraine medication was positively associated with all stillbirths (rate ratio [RR] range 1.3-1.6). Fertility drugs were positively associated with stillbirths in total and stillbirths due to complications of the placenta, cord and membranes (RR = 1.8, 95% CI 0.8, 4.1; and RR = 2.5, 95% CI 0.9, 7.2 respectively). No associations were found for aspirin, amniocentesis, diagnostic X-rays or fever, consistent with previous studies. This report is among the few studies of specific causes of stillbirth and medical exposures by gestational time window. [ABSTRACT FROM AUTHOR]

Background: Gestational exposure to several common agricultural pesticides can induce developmental neurotoxicity in humans, and has been associated with developmental delay and autism. Objectives: We evaluated whether residential proximity to agricultural pesticides during pregnancy is associated with autism spectrum disorders (ASD) or developmental delay (DD) in the Childhood Autism Risks from Genetics and Environment (CHARGE) study. Methods: The CHARGE study is a population-based case–control study of ASD, DD, and typical development. For 970 participants, commercial pesticide application data from the California Pesticide Use Report (1997–2008) were linked to the addresses during pregnancy. Pounds of active ingredient applied for organophophates, organochlorines, pyrethroids, and carbamates were aggregated within 1.25‑km, 1.5‑km, and 1.75‑km buffer distances from the home. Multinomial logistic regression was used to estimate the odds ratio (OR) of exposure comparing confirmed cases of ASD (n = 486) or DD (n = 168) with typically developing referents (n = 316). Results: Approximately one-third of CHARGE study mothers lived, during pregnancy, within 1.5 km (just under 1 mile) of an agricultural pesticide application. Proximity to organophosphates at some point during gestation was associated with a 60% increased risk for ASD, higher for third-trimester exposures (OR = 2.0; 95% CI: 1.1, 3.6), and second-trimester chlorpyrifos applications (OR = 3.3; 95% CI: 1.5, 7.4). Children of mothers residing near pyrethroid insecticide applications just before conception or during third trimester were at greater risk for both ASD and DD, with ORs ranging from 1.7 to 2.3. Risk for DD was increased in those near carbamate applications, but no specific vulnerable period was identified. Conclusions: This study of ASD strengthens the evidence linking neurodevelopmental disorders with gestational pesticide exposures, particularly organophosphates, and provides novel results of ASD and DD associations with, respectively, pyrethroids and carbamates. [ABSTRACT FROM AUTHOR]

Fragile X syndrome (FXS) is a neuro-developmental disorder characterized by intellectual disabilities and autism spectrum disorders (ASD). Expansion of a CGG trinucleotide repeat (>200 repeats) in the 5′UTR of the fragile X mental retardation gene, is the single most prevalent cause of cognitive disabilities. Several screening studies for FXS, among individuals with ID from different ethnic populations, have indicated that the prevalence of the syndrome varies between 0.5 and 16 %. Because the high co-morbidity with autism, we have conducted a screening study of the cohort from CHARGE, a large-scale, population-based, case control study. We have identified six subjects carrying an expanded allele, which emphasize the importance of screening for FXS in a population with intellectual disabilities and ASD. [ABSTRACT FROM AUTHOR]

Objectives Despite increasing availability of global positioning system (GPS), no research has been conducted to analyze GPS data for exposure opportunities associated with time at indoor and outdoor microenvironments. We developed location-based and time-weighted spatial measures that incorporate indoor and outdoor time-location data collected by GPS. Methods Time-location data were drawn from 38 female subjects in California who wore a GPS device for seven days. Ambient standard deviational ellipse was determined based on outdoor locations and time duration, while indoor time weighted standard deviational ellipse (SDE) was developed to incorporate indoor and outdoor times and locations data into the ellipse measure. Results Our findings indicated that there was considerable difference in the sizes of exposure potential measures when indoor time was taken into consideration, and that they were associated with day type (weekday/weekend) and employment status. Conclusions This study provides evidence that time-location weighted measure may provide better accuracy in assessing exposure opportunities at different microenvironments. The use of GPS likely improves the geographical details and accuracy of time-location data, and further development of such location-time weighted spatial measure is encouraged. [ABSTRACT FROM AUTHOR]

We analyzed data from case groups of 538 children with autism spectrum disorders (ASD) and 163 with developmental delays (DD), and from 421 typically developing controls to assess associations with maternal influenza or fever during pregnancy. Exposure information was obtained by telephone interviews, and outcomes were clinically confirmed. Though neither ASD nor DD was associated with influenza, both were associated with maternal fever during pregnancy: OR's (odds ratios) were 2.12 (95 % CI 1.17, 3.84) and 2.50 (95 % CI 1.20, 5.20) respectively. However, the fever-associated ASD risk was attenuated among mothers who reported taking antipyretic medications (OR = 1.30, 95 % CI 0.59, 2.84), but remained elevated for those who did not (OR = 2.55, 95 % CI 1.30, 4.99). [ABSTRACT FROM AUTHOR]

Both self-report and industrial hygienist (IH) assessed parental occupational information were used in this pilot study in which 174 families (93 children with ASD and 81 unaffected children) enrolled in the Childhood Autism Risks from Genetics and Environment study participated. IH results indicated exposures to lacquer, varnish, and xylene occurred more often in the parents of children with ASD compared to the parents of unaffected children. Parents of children with ASD were more likely to report exposures to asphalt and solvents compared to parents of unaffected children. This study was limited by the small sample size, but results suggest that workplace exposures to some chemicals may be important in the etiology of ASD and deserve further investigation. [ABSTRACT FROM AUTHOR]

ABSTRACT Background: Periconceptional folate is essential for proper neuro-development. Objective: Maternal folie acid intake was examined in relation to the risk of autism spectrum disorder (ASD) and developmental delay (DD). Design: Families enrolled in the CHARGE (CHildhood Autism Risks from Genetics and Environment) Study from 2003 to 2009 were included if their child had a diagnosis of ASD (n = 429), DD (n = 130), or typical development (TD; n = 278) confirmed at the University of California Davis Medical Investigation of Neurode- velopmental Disorders Institute by using standardized clinical assessments. Average daily folie acid was quantified for each mother on the basis of dose, brands, and intake frequency of vitamins, supplements, and breakfast cereals reported through structured telephone interviews. Results: Mean (±SEM) folie acid intake was significantly greater for mothers of TD children than for mothers of children with ASD in the first month of pregnancy (PI; 779.0 ± 36.1 and 655.0 ± 28.7 /µg, respectively; P < 0.01). A mean daily folic acid intake of >600 /µg (compared with <600 µg) during PI was associated with reduced ASD risk (adjusted OR: 0.62; 95% CI: 0.42, 0.92; P = 0.02), and risk estimates decreased with increased folie acid (P-trend = 0.001). The association between folie acid and reduced ASD risk was strongest for mothers and children with MTHFR 677 C>T variant genotypes. A trend toward an association between lower maternal folie acid intake during the 3 mo before pregnancy and DD was observed, but not after adjustment for confounders. Conclusions: Periconceptional folie acid may reduce ASD risk in those with inefficient folate metabolism. The replication of these findings and investigations of mechanisms involved are warranted. Am J Clin Nutr 20\2;96:80-9. [ABSTRACT FROM AUTHOR]

Traditionally, use of household and personal care products has been collected through questionnaires, which is very time consuming, a burden on participants, and prone to recall bias. As part of the SUPERB Project (Study of Use of Products and Exposure-Related Behaviors), a novel platform was developed using bar codes to quickly and reliably determine what household and personal care products people have in their homes and determine the amount used over a 1-week period. We evaluated the acceptability and feasibility of our methodology in a longitudinal field study that included 47 California households, 30 with young children and 17 with an older adult. Acceptability was defined by refusal rates; feasibility was evaluated in terms of readable bar codes, useful product information in our database for all readable barcodes, and ability to find containers at both the start and end of the week. We found 63% of personal care products and 87% of the household care products had readable barcodes with 47% and 41% having sufficient data for product identification, respectively and secondly, the amount used could be determined most of the time. We present distributions for amount used by product category and compare inter- and intra-person variability. In summary, our method appears to be appropriate, acceptable, and useful for gathering information related to potential exposures stemming from the use of personal and household care products. A very low drop-out rate suggests that this methodology can be useful in longitudinal studies of exposure to household and personal care products. [ABSTRACT FROM AUTHOR]

Background: Causes of autism are unknown. Associations with maternal nutritional factors and their interactions with gene variants have not been reported.Methods: Northern California families were enrolled from 2003 to 2009 in the CHARGE (CHildhood Autism Risks from Genetics and Environment) population-based case-control study. Children aged 24-60 months were evaluated and confirmed to have autism (n = 288), autism spectrum disorder (n = 141), or typical development (n = 278) at the University of California-Davis Medical Investigation of Neurodevelopmental Disorders Institute using standardized clinical assessments. We calculated adjusted odds ratios (ORs) for associations between autism and retrospectively collected data on maternal vitamin intake before and during pregnancy. We explored interaction effects with functional genetic variants involved in one-carbon metabolism (MTHFR, COMT, MTRR, BHMT, FOLR2, CBS, and TCN2) as carried by the mother or child.Results: Mothers of children with autism were less likely than those of typically developing children to report having taken prenatal vitamins during the 3 months before pregnancy or the first month of pregnancy (OR = 0.62 [95% confidence interval = 0.42-0.93]). Significant interaction effects were observed for maternal MTHFR 677 TT, CBS rs234715 GT + TT, and child COMT 472 AA genotypes, with greater risk for autism when mothers did not report taking prenatal vitamins periconceptionally (4.5 [1.4-14.6]; 2.6 [1.2-5.4]; and 7.2 [2.3-22.4], respectively). Greater risk was also observed for children whose mothers had other one-carbon metabolism pathway gene variants and reported no prenatal vitamin intake.Conclusions: Periconceptional use of prenatal vitamins may reduce the risk of having children with autism, especially for genetically susceptible mothers and children. Replication and mechanistic investigations are warranted. [ABSTRACT FROM AUTHOR]

Background: Studies of season of birth or season of conception can provide clues about etiology. We investigated whether certain months or seasons of conception are associated with increased risk of autism spectrum disorders, for which etiology is particularly obscure.Methods: The study population comprises 6,604,975 children born from 1990 to 2002 in California. Autism cases (n = 19,238) were identified from 1990 through 2008 in databases of the California Department of Developmental Services, which coordinates services for people with developmental disorders. The outcome in this analysis was autism diagnosed before the child's sixth birth date. The main independent variables were month of conception and season of conception (winter, spring, summer, and fall). Multivariate logistic regression models were used to estimate odds ratios (ORs) with their 95% confidence intervals (CIs) for autism by month of conception.Results: Children conceived in December (OR = 1.09 [95% CI = 1.02-1.17]), January (1.08 [1.00-1.17]), February (1.12 [1.04-1.20]), or March (1.16 [1.08-1.24]) had higher risk of developing autism compared with those conceived in July. Conception in the winter season (December, January, and February) was associated with a 6% (OR = 1.06, 95% CI = 1.02-1.10) increased risk compared with summer.Conclusions: Higher risks for autism among those conceived in winter months suggest the presence of environmental causes of autism that vary by season. [ABSTRACT FROM AUTHOR]

Background: Little 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. Objectives: We 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. Methods: Data 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. Results: Adjusting 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. Conclusions: Living near a freeway was associated with autism. Examination of associations with measured air pollutants is needed. [ABSTRACT FROM AUTHOR]

The article focuses on an observational study which evaluated mitochondrial defects in children with autism. The study used data collected from patients aged 2 to 5 years old who were a subset of children participating in the Childhood Autism Risk From Genes and Environmental study in California. The main outcome measures of the study are noted, which include oxidative phosphorylation capacity, mitochondrial rate of hydrogen peroxide production and plasma lactate and pyruvate. Results indicated that autistic children were more likely to have mitochondrial dysfunction, mtDNA overreplication and mtDNA deletions than typically developing children.

Background: Exposure to toxic chemicals in the home is a growing concern. This report presents an overview of the recruitment, methods for data collection, instruments used to collect data, and participant demographics for a study examining behaviors that influence exposure to environmental toxins in the home environment, also known as SUPERB (Study of Use of Products and Exposure Related Behaviors). Methods: The methods involved three different platforms: telephone interviews, internet-based surveys, and home-based monitoring. The purposes of SUPERB were: first, to compare data collection platforms with regard to feasibility, acceptability and reliability; and second, to provide longitudinal population-based data characterizing seasonal and long-term changes in exposure-related behaviors including food consumption, temporal-spatial activity, and household product use. Results: Two cohorts of households were enrolled: families (one parent and one child) from northern California and older individuals (age 55+) from central California. Parents (n = 499) in Northern California families were on average 36 years of age, 47.1% were Latino or nonwhite, and 10.2% took the survey in Spanish. Most of the children enrolled (n = 566) were under 6 years (82.7%). The older adults enrolled (n = 156) were, on average, 66 years of age and 23.7% were Latino or nonwhite, but only 2.6% completed the survey in Spanish. Conclusions: We found that oversampling was successful in improving recruitment of under-represented subgroups, such as those with low education, thereby increasing diversity of our study sample. Protocols that minimize participant time, e.g., use of bar scanners and scales rather than questionnaires regarding use of household products, and the implementation of these protocols by staff who built relationships of trust, resulted in high retention over a longitudinal data collection scheme. A relatively small fraction of those who volunteer for longitudinal internet surveys are consistent in filling them out. Future reports will provide critical information on cross-sectional, seasonal and longitudinal patterns of exposure related behaviors in young children, parents of young children, and older adults. [ABSTRACT FROM AUTHOR]

The potential association between fetal death and residential proximity to agricultural pesticide applications was examined in 10 California counties for 1984. A case-cohort analysis utilized 319 cases of selected causes of fetal death other than congenital anomalies and 611 noncases. A statewide database of all applications of restricted pesticides was linked to maternal address; residential proximity within 1 mile (1.6 km) provided a surrogate for daily exposure. Pesticides were grouped by chemical class and mechanism of acetylcholinesterase inhibition. Multivariate proportional hazards models using time-dependent exposure variables were fit for each pesticide grouping. Overall, pesticides showed no strong association with fetal death. Slightly elevated risks were observed for women who resided near applications of halogenated hydrocarbons, carbamates, estrogenic pesticides, and carbamate acetylcholinesterase inhibitors during the second trimester, with hazard ratios of 1.3 (95% confidence interval (CI): 1.0, 1.8), 1.3 (95% CI: 1.0, 1.8), 1.4 (95% CI: 0.8, 2.5), and 1.3 (95% CI: 1.0, 1.8), respectively. In a month-by-month analysis, elevated risks were observed when exposure occurred during gestational months 3 and 4 for carbamates and carbamate inhibitors and during months 4 and 5 for halogenated hydrocarbons. Since previous studies have relied on personal recall of exposure, major strengths of this study were the objective source for environmental pesticide exposure assessment and the use of data on the timing of exposure. [ABSTRACT FROM PUBLISHER]

Introduction Certain phenols and phthalates are used in many consumer products including personal care products (PCPs). Aims We aimed to study the associations between the use of PCPs and urinary concentrations of biomarkers of select phenols and phthalates among Californian adults and their children. As an additional aim we compared phenols and phthalate metabolites concentrations measured in adults and children urine samples collected the same day. Methods Our study relied on a subsample of 90 adult–child pairs participating in the Study of Use of Products and Exposure Related Behavior (SUPERB). Each adult and child provided one to two urine samples in which we measured concentrations of selected phenols and phthalate metabolites. We computed Spearman correlation coefficients to compare concentrations measured in adults and children urine samples collected the same day. We used adjusted linear and Tobit regression models to study the associations between the use of PCPs in the past 24 h and biomarker concentrations. Results Benzophenone-3 and parabens concentrations were higher in adults compared to their children. Conversely children had higher mono- n -butyl phthalate and mono-isobutyl phthalate concentrations. No significant difference was observed for the other compounds. The total number of different PCPs used was positively associated with urinary concentrations of methyl, propyl and butyl parabens and the main metabolite of diethyl phthalate in adults. Among children, the use of a few specific products including liquid soap, hair care products and sunscreen was positively associated with urinary concentrations of some phenols or phthalate metabolites. Discussion These results strengthen the body of evidence suggesting that use of PCPs is an important source of exposure to parabens and diethyl phthalate in adults and provide data on exposure to selected phenols and phthalates through use of PCPs in children. [ABSTRACT FROM AUTHOR]

Perfluorinated compounds (PFCs) have been widely used in industrial applications and consumer products. Their persistent nature and potential health impacts are of concern. Given the high cost of collecting serum samples, this study is to understand whether we can quantify PFC serum concentrations using factors extracted from questionnaire responses and indirect measurements, and whether a single serum measurement can be used to classify an individual′s exposure over a one-year period. The study population included three demographic groups: young children (2–8 years old) ( N =67), parents of young children (<55 years old) ( N =90), and older adults (>55 years old) ( N =59). PFC serum concentrations, house dust concentrations, and questionnaires were collected. The geometric mean of perfluorooctane sulfonic acid (PFOS) was highest for the older adults. In contrast, the geometric mean of perfluorooctanoic acid (PFOA) was highest for children. Serum concentrations of the parent and the child from the same family were moderately correlated (Spearman correlation ( r )=0.26–0.79, p <0.05), indicating common sources within a family. For adults, age, having occupational exposure or having used fire extinguisher, frequencies of consuming butter/margarine, pork, canned meat entrées, tuna and white fish, freshwater fish, and whether they ate microwave popcorn were significantly positively associated with serum concentrations of individual PFCs. For children, residential dust concentrations, frequency of wearing waterproof clothes, frequency of having canned fish, hotdogs, chicken nuggets, French fries, and chips, and whether they ate microwave popcorn were significant positive predictors of individual PFC serum concentrations. In addition, the serum concentrations collected in a subset of young children ( N =20) and the parents ( N =42) one year later were strongly correlated ( r =0.68–0.98, p <0.001) with the levels measured at the first visits, but showed a decreasing trend. Children had moderate correlation ( r =0.43) between serum and dust concentrations of PFOS, indicating indoor sources contribute to exposure. In conclusion, besides food intake, occupational exposure, consumer product use, and exposure to residential dust contribute to PFC exposure. The downward temporal trend of serum concentrations reflects the reduction of PFCs use in recent years while the year-to-year correlation indicates that a single serum measurement could be an estimate of exposure relative to the population for a one-year period in epidemiology studies. [ABSTRACT FROM AUTHOR]

Abstract: Given the concern over the potential for health risks associated with certain ingredients (e.g., phthalates) in personal care products, usage patterns of ∼30 types of personal care products (e.g., shampoo, sunscreen, fragrance, etc.) were collected in 604 California households through a telephone interview. Preferences in selecting products, e.g., scented or unscented, aerosol, and brand loyalty, were also investigated. Participants were recruited in three age groups, children (mostly preschoolers), their parents, and adults age 55 or older. Use frequencies of various product types varied by sex, age group, race, education, and climatic region. Product use by parent and child from the same household were correlated. Use frequencies of products in the same class (e.g., skincare) were moderately correlated, which may impact aggregate exposures. Use frequencies observed in this study were generally in the same range as those reported in the EPA Exposure Factor Handbook, but we found differences for some individual products. Our study provides additional data on population-based usage patterns of a large collection of commonly used personal care products pertaining to several age groups and socio-demographic strata. This information will be valuable for exposure and risk assessments. [ABSTRACT FROM AUTHOR]

This study determined the body burden of PBDEs in 100 California children, and evaluated associations with sociodemographic, household, and dietary factors. In national and international comparisons, California dust, breast milk, and human serum samples contain higher concentrations of PBDEs. Higher levels in children suggest exposure pathways depend upon age. Plasma samples were analyzed for PBDEs using GC/MS. Circulating levels of PBDEs were 10-to 1000-fold higher than similar aged populations in Mexico and Europe, 5-times higher than similar aged children across the U.S., and 2- to 10-fold higher than U.S. adults. Increased levels of higher-brominated congeners were associated with the recent purchase of new upholstered furniture or mattresses and consumption of pork. Concentrations of lower-brominated congeners increased with frequency of poultry consumption. Lower maternal education was independently and significantly associated with higher levels of most congeners in the children. [ABSTRACT FROM AUTHOR]

Human exposure to per- and polyfluoroalkyl substances (PFAS) has changed since the early 2000s, in part, because of the phase-out and replacement of some long-chain PFAS. Studies of PFAS exposure and its temporal changes have been limited to date mostly to adults and pregnant women. We examined temporal trends and determinants of PFAS serum concentrations among mothers with a young child who participated in the CHARGE ( CH ildhood A utism R isk from G enetics and E nvironment) case-control study. We quantified nine PFAS in serum samples collected from 2009 to 2016 in 450 Northern California mothers when their child was 2–5 years old. With five compounds that were detected in more than 50% of the samples, we performed multiple regression to estimate least square geometric means (LSGMs) of PFAS concentrations with adjustment for sampling year and other characteristics that may affect maternal concentrations (e.g., breastfeeding duration). We also used time-related regression coefficients to calculate percent changes over the study period. LSGM concentrations of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexane sulfonate (PFHxS) decreased over the study period [percent change (95% confidence interval): −10.7% (−12.7%, −8.7%); −10.8% (−12.9%, −8.5%); −8.0% (−10.5%, −5.5%), respectively]. On the other hand, perfluorononanoate (PFNA) and perfluorodecanoate (PFDA) showed mixed time trends. Among the selected covariates, longer breastfeeding duration was associated with decreased maternal serum concentrations of PFOA, PFOS, PFHxS, PFNA and PFDA. Our study demonstrated that body burden of some common long-chain PFAS among California mothers with a young child decreased over the study period and that breastfeeding appears to contribute to the elimination of PFAS in lactating mothers. • PFOA, PFOS, PFHxS, and Me-FOSAA monotonically decreased during the study period. • PFNA, PFDeA and PFUA exhibited mixed trends. • Breastfeeding contributed to the elimination of the common PFAS in lactating mothers. • Our study participants had lower PFAS serum concentrations than NHANES participants. [ABSTRACT FROM AUTHOR]