Table 3.
Studies investigating the association between exposure to O3 and ASD development.
| Authors and Year | Study Design | Sample Size/Country | ASD Outcome Assessment | Exposure Assessment | Method of Analysis | Adjustment Variables | Time Window of Exposure | Main Findings |
|---|---|---|---|---|---|---|---|---|
| McGuinn et al., 2020 [23] |
Case-control | 674 ASD cases and 855 controls fromCalifornia, Colorado, Georgia, Maryland, North Carolina, and Pennsylvania | ASD case classification based on the results from the ADOS (Autism Diagnostic Observation Schedule) and ADI-R (Autism Diagnostic Interview-Revised) | Satellite-based model to assign air pollutant exposure (PM2.5, O3) averages during several critical periods of neurodevelopment | Logistic regression model | -study site -maternal age -maternal education -maternal race -maternal smoking, -month and year of birth |
-3 months before pregnancy -each trimester of pregnancy -the entire pregnancy -first year of life |
There was a variation by exposure time period for the O3–ASD relation, with a stronger association observed during the third trimester of pregnancy and an OR of 1.2 (95%CI: 1.1, 1.4) per 6.6 ppb increase in O3 |
| Kaufman et al., 2019 [25] |
Case-control | 428 ASD cases and 6420 controls from metropolitan Cincinnati area in southwest Ohio | ASD diagnosis according to International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) | Daily PM2.5 individual exposure estimations provided by the United States Environmental Protection Agency (US EPA), based on their residential address | Logistic regression model | -maternal and birth-related confounders -multiple temporal exposure windows |
-each trimester pregnancy -first year of life -second year of life |
Positive association with O3 exposure during the 2nd year of life (OR range across categories: (1.29–1.42) |
| Becerra et al., 2013 [30] |
Case-control | 7603 ASD cases and 10 controls per case from Los Angeles, California | The diagnosis of ASD was based on the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IV-R) | Modeled concentrations of PM2.5 from air monitoring station 1993–2006, assigned by residential address at delivery/birth | Conditional logistic regression | -maternal age -maternal place of birth -race -education -type of birth -parity -insurance type -gestational age at birth |
-pregnancy | Positive association with O3 during pregnancy and ASD. 1.12 (95%CI, 1.06, 1.19) per 11.54 ppb increase in O3 |
| Jo et al., 2019 [32] |
Cohort | 246,420 children from Southern California | ASD diagnosis according to International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) | PM2.5 measured at regulatory air monitoring stations was interpolated to estimate exposures during preconception and each pregnancy trimester, and first year of life at each child’s birth address | Cox regression models | -birth year -relevant maternal and child characteristics |
-preconception -trimester 1,2,3 -year 1 |
No significant association between O3 and ASD |
| Jung et al., 2013 [39] |
Case-Control | 49,073 children from Taiwan | ASD diagnosis according to International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) | Inverse distance weighting method was used to form exposure parameter for PM10 | Cox proportional hazards (PH) model | -age -anxiety -gender -intellectual disabilities -preterm -SES |
-postnatal | The study suggested an association between O3 exposure in the first for years of life and ASD |