A recent study has found that air pollution exposure could impair foetal growth, with a potential to cause neurological defects. The study, from the All India Institute for Medical Sciences (AIIMS), Delhi, sheds light on the molecular pathways through which pollution disrupts early child development, and reinforces existing evidence of the wide-ranging health impacts of air pollution.
Exposure to PM2.5 particles are known to cause respiratory disease, worsen hypertension and diabetes, and exacerbate cardiovascular illnesses. Emerging evidence has suggested that prolonged exposure to air pollution can cause low birthweight, stillbirth, and preterm births. The AIIMS study, however, demonstrates how air pollution disrupts cellular activity to curb healthy foetal development.
“The missing link we presented in this research was how air pollution causes the reduction in a protein that’s very important for foetal development,” explained Dr. Subhradip Karmakar, an author of the study and a professor of biochemistry at AIIMS.
In pregnant mothers, inhaling ultrafine, PM2.5 and PM10 particles can cause oxidative stress which triggers an inflammatory response that activates cytokines – proteins which act on immune threats. This surge in inflammatory response can pass through the placenta, as do ultrafine particles and environmental pollutants such as heavy metals, which cause a reduction in the IGFBP3 protein, a critical regulator of cell growth, in foetuses. “This isn’t the only significant protein for foetal development. There might be other significant proteins that are also affected,” said Karmakar.
The study observed this mechanism in pregnant rats exposed to air pollution, and tracked postnatal neurodevelopment in pups. According to the study, rat pups exposed to air pollution experienced “persistent postnatal deficits in motor coordination, cognitive processing, and emotional regulation, consistent with neurobehavioral disruption and sex-specific vulnerability induced by in utero particulate exposure.”
The observations in the experiment were correlated with pregnancy outcomes among women from highly exposed climates. Delivery data from hospitals in New Delhi, where women were exposed to higher ambient PM2.5 levels, were associated with more low-birth-weight babies and more preeclampsia, a pregnancy complication, compared to women from lower-exposure settings in Deoghar, Jharkhand.
“The next phase of this study is to track the IGFBP3 protein as a biomarker in human pregnancies, which would give us greater insight into how air pollution causes developmental defects,” said Karmakar.
Banner image: A November 2017 photo of a woman carrying an infant outside a shop selling air purifiers at a market place in New Delhi. (AP Photo/Altaf Qadri, File)
Credits
