Between 2015 and 2022, the Center for Research on Early Childhood Exposure and Development in Puerto Rico (CRECE) studied how mixtures of environmental exposures and other factors affect the health and development of infants and children living in the heavily-contaminated island of Puerto Rico.

Since 2016, CRECE has participated in the NIH’s Environmental influences on Child Health Outcomes (ECHO) program. ECHO unites mother and child cohorts across the United States to better understand the impacts of environmental exposures on children’s health. More information about the CRECE cohort’s involvement, including links to recent ECHO publications involving CRECE researchers, are available on NIH RePORTER.

Air Pollution

Researchers found a link between high levels of atmospheric fine particulate matter, or PM2.5, and preterm birth (PTB). PTB is associated with a host of adverse health outcomes and can negatively impact child development. Using data from US EPA air monitors in Puerto Rico, researchers estimated PM2.5 exposures in the birth cohort and compared against the gestational age at birth. Prenatal PM2.5 exposure was associated with a small but significant increase in the risk of preterm birth, even when accounting for other factors.

Exposure to high levels of air pollution during pregnancy was linked with neurodevelopmental delays during infancy. Researchers measured infant non-nutritive suck (NNS) patterns, an early indicator of neurodevelopment. Using air quality data from three monitoring sites in the study area, researchers investigated the association between PM2.5 and NNS patterns. Results showed decreased NNS amplitude with higher levels of exposure to PM2.5.

Chemical Exposures

Exposure to several chemicals during pregnancy is also associated with higher rates of preterm birth. Prenatal exposure to triclocarban, a chemical commonly found in antibacterial soap, was associated with a decrease in gestational age. Triclosan, a similar chemical, was associated with decreased gestational age in female infants and increased gestational age in male infants. Higher levels of bisphenol-S (BPS, a common replacement for BPA in plastics) later in pregnancy was associated with shorter gestational age. A later study showed that these associations were stronger in pregnant women who had experienced more negative life events, suggesting that stress makes the body more vulnerable to chemical exposure. Lastly, the team looking at glyphosate, which is found in popular herbicides like RoundUp. Preterm birth was significantly associated with high levels of glyphosate in urine later in pregnancy (24-28 weeks).

The research team also looked at prenatal chemical exposures and NNS parameters. Higher prenatal levels of phthalates, another common chemical often found in plastics, led to changes in the amplitude and frequency of NNS in infants that were not born prematurely.

Toxicity of Water & Air Pollutant Mixtures

CRECE researchers also investigated the toxicity of tap water and air pollutant mixtures. In tap water, 18 trace elements and 28 organic micropollutants were found, all below the minimum contaminant level or health-based screening level. Strontium, copper, and barium had the highest average concentrations in tap water. For the air pollutant mixtures, researchers measured the toxicity of air samples taken from 3 monitoring sites in Puerto Rico and assessed them for biomarkers of oxidative stress, DNA damage, protein stress, chemical stress, and general stress.