Place matters. The air you breathe. The noises and sounds that surround you. The amount and quality of concrete under your feet. The neighborhood where you live, work, and play can have a strong influence on your health—in and out of the womb. Your social and physical environment can greatly impact your health, even before birth. The combination of these environmental and social characteristics can have an even more pronounced effect.

In a recently published study focusing on term singleton births across New York City, we revisited the role of prenatal ambient nitrogen dioxide (NO₂) air pollution and 23 individual community-level stressors on birth weight for infants born full term. These stressors included indicators of crime and violence, physical disorder, noise disruption, socioeconomic position, and access to healthcare. As expected, we found that higher residential NO₂ was associated with lower birth weights.

We then tested whether the effects of air pollution differed in those locations with higher stressor exposures. We tested a range of social stressors to identify potential stressors that most affected susceptibility.  We found that violent crime measurements consistently modified the relationship between air pollution and birth weight. This didn’t surprise us –prior qualitative studies have shown us that violence is a paramount urban stressor, which bears a unique toll on the population.

What did surprise us was that, at very high levels of violent crime, we didn’t see much effect of air pollution. While infants born in communities with high violence exposures had lower birth weights, on average, air pollution seemed to have a more reduced effect when compared to infants born in communities with low violence exposures. We suspect that this may be a type of saturation effect - the social stressors in those communities had already taken such a toll on the birth weights that there was little left to be explained by pollution.

So what does this mean?

Maternal stress arising from environmental and non-chemical (e.g., social) exposures can adversely affect birth outcomes and, likely, long-term health. However, at very high stressor exposures, these factors may be a highly influential determinant of health, making the benefits of improved air quality hard to detect. Our conclusion does not negate the critical implications of environmental effects on health —lower air quality can have profound consequences for population health. Rather, this study highlights the need to incorporate measures of neighborhood quality, social deprivation, and safety when studying the built environment and to consider their interactions.

A convergence and linkage of high-quality environmental, social, and health data sources 

This work would not have been possible without the use of high-quality data products collected, curated, and maintained by federal, state, local, and academic partners. We included highly resolved air pollution data based on data collected by the New York City (NYC) Department of Health and Mental Health (DOHMH) and the US Environmental Protection Agency, and processed by researchers.

Maternal and neonatal characteristics were gathered using birth records from NYC’s Bureau of Vital Records. Data sources for community-level social stressors include the New York Police Department, the NYC Administration for Children’s Services, the NYC Parks Department, Housing Preservation and Development, and more!  The utility of data linkages through multiple sources is a valuable asset towards answering complex population health questions within the built environment.

If interested in learning more about the topic or the comprehensive, high-quality data sources we used, you can read the full paper here: https://rdcu.be/epCcM