Pre- and postnatal exposure to multiple ambient air pollutants and child behavioral problems at five years of age

Prenatal exposure to air pollutant mixtures and birthweight in the upstate KIDS cohort

BACKGROUND

Single-pollutant models have linked prenatal PM2.5 exposure to lower birthweight. However, analyzing air pollutant mixtures better captures pollutant interactions and total effects. Unfortunately, strong correlations between pollutants restrict traditional methods.

OBJECTIVES

We explored the association between exposure to a mixture of air pollutants during different gestational age windows of pregnancy and birthweight.

METHODS

We included 4,635 mother-infant dyads from a New York State birth cohort born 2008-2010. Air pollution data were sourced from the EPA's Community Multiscale Air Quality model and matched to the census tract centroid of each maternal home address. Birthweight and gestational age were extracted from vital records. We applied linear regression to study the association between prenatal exposure to PM2.5, PM10, NOX, SO2, and CO and birthweight during six sensitive windows. We then utilized Bayesian kernel machine regression to examine the non-linear effects and interactions within this five-pollutant mixture. Final models adjusted for maternal socio-demographics, infant characteristics, and seasonality.

RESULTS

Single-pollutant linear regression models indicated that most pollutants were associated with a decrement in birthweight, specifically during the two-week window before birth. An interquartile range increase in PM2.5 exposure (IQR: 3.3 µg/m3) from the median during this window correlated with a 34 g decrement in birthweight (95 % CI: -54, -14), followed by SO2 (IQR: 2.0 ppb; β: -31), PM10 (IQR: 4.6 µg/m3; β: -29), CO (IQR: 60.8 ppb; β: -27), and NOX (IQR: 7.9 ppb; β: -26). Multi-pollutant BKMR models revealed that PM2.5, NOX, and CO exposure were negatively and non-linearly linked with birthweight. As the five-pollutant mixture increased, birthweight decreased until the median level of exposure.

DISCUSSION

Prenatal exposure to air pollutants, notably PM2.5, during the final two weeks of pregnancy may negatively impact birthweight. The non-linear relationships between air pollution and birthweight highlight the importance of studying pollutant mixtures and their interactions.

The influence of environmental particulate matter exposure during late gestation and early life on the risk of neurodevelopmental disorders: A systematic review of experimental evidences

Particulate matter (PM) is a major component of ambient air pollution (AAP), being widely associated with adverse health effects. Epidemiological and experimental studies point towards a clear implication of AAP on the development of central nervous system (CNS) diseases. In this sense, the period of most CNS susceptibility is early life, when the CNS is maturing. In humans the last trimester of gestation is crucial for brain maturation while in rodents, due to the shorter gestational period, the brain is still immature at birth, and early postnatal development plays a significant role. The present systematic review provides an updated overview and discusses the existing literature on the relationship between early exposure to PM and neurodevelopmental outcomes in experimental studies. We included 11 studies with postnatal exposure and 9 studies with both prenatal and postnatal exposure. Consistent results between studies suggest that PM exposure could alter normal development, triggering impairments in short-term memory, sociability, and impulsive-like behavior. This is also associated with alterations in synaptic plasticity and in the immune system. Interestingly, differences have been observed between sexes, although not all studies included females. Furthermore, the developmental window of exposure seems to be crucial for effects to be observed in the future. In summary, air pollution exposure during development affects subjects in a time- and sex-dependent manner, the postnatal period being more important and being males apparently more sensitive to exposure than females. Nevertheless, additional experimental investigations should prioritize the examination of learning, impulsivity, and biochemical parameters, with particular attention provided to disparities between sexes.

Social inequalities, green and blue spaces and mental health in 6-12 years old children participating in the INMA cohort

Availability of green and blue spaces in the area of residence has been related to various health outcomes during childhood, including mental health. These environmental exposures are not evenly distributed among socioeconomic groups, which may increase social inequalities in mental health. The mechanisms through which natural environments may promote mental health are numerous and diverse. This study aimed to explore 1) the potential associations of socioeconomic variables (SES and maternal education attainment) with mental health scores and residential greenness, blueness and NO2 metrics, and, 2) the association between greenness and blueness metrics and mental health scores of children in the Spanish INfancia y Medio Ambiente (INMA) birth cohort at two different time points. The study samples were composed of 1738 six-to eight-year-olds (49% female) and 1449 ten-to twelve-year-olds (living in Asturias, Gipuzkoa, Sabadell and Valencia, Spain. Individual Normalized Difference Vegetation Index (NDVI) values in 100-, 300- and 500-m buffers and availability of green and blue spaces >5000 m2 in 300-m buffers were calculated using Geographic Information Systems software. Residential NO2 values were estimated using land use regression models. Internalizing, externalizing and total problems scores were obtained with the Strengths and Difficulties Questionnaire (SDQ). Linear and logistic mixed-effects models revealed unequal distribution of environmental exposures by SES and maternal education but did not show statistically significant associations between greenness and blueness metrics and mental health indicators. The protective effect of green and blue spaces on children's mental health could not be confirmed in this study and therefore further research is required.