Exposure to air pollution may cause lower infant birth weight

Hebrew University researchers have found strong correlations between the level of air pollutant PM2.5 and low birth weight.

 The unrecognized villages around Ramat Hovav which suffer from a high level of air pollution from nearby evaporation ponds of the chemicals and the IEC power plant. December 28, 2017 (photo credit: YANIV NADAV/FLASH90)
The unrecognized villages around Ramat Hovav which suffer from a high level of air pollution from nearby evaporation ponds of the chemicals and the IEC power plant. December 28, 2017
(photo credit: YANIV NADAV/FLASH90)

There have been a number of studies in the past that attempted to answer the question of the effect of the environment on babies' health, but they have not been able to gather sufficient data from the Middle East.

What are PM2.5 particles? 

A study by a team from Hebrew University's Hadassah Braun School of Public Health used personal, anonymized data and detailed high-resolution pollutant data that enabled them to produce more accurate statistical analyses.

The study, led by Wissam Abu Ahmad, a doctoral student of Levine and Prof. Ronit Nirel at HU’s Department of Statistics and Data Science, looked at the link between an air pollutant known as PM2.5 and the birth weight of 380,000 babies born to mothers all over in Israel during the years 2004-2015. Their findings were published in the peer-reviewed journal Environmental Research.

PM2.5 particles are air pollutants that originate from fuel combustion (cars trucks etc.) PM2.5 causes the air to be hazy, and because these particles are so small (less than 2.5 microns: about 30 times smaller than hair) they can penetrate the narrowest airways and impair lung function.

Israel has the highest fertility rate among the OECD countries and has high levels of air pollutant PM2.5, making the country a prime location to look for a connection between low birth weight and poor air quality.

 Baby foot (Illustrative) (credit: Negative Space) Baby foot (Illustrative) (credit: Negative Space)

"As the model included siblings, it enabled the estimation of the variance in low birth weight to be accounted for by variances between different mothers, leading to more accurate estimates" explained Abu Ahmad.

The data used by the research team included personal anonymized data on the mothers, including the area where they lived and the weight of their babies at birth (provided by Maccabi Health Services), and daily air pollutant concentration over each square kilometer of Israel, derived from satellite data (provided by Ben Gurion University).

Clear-cut answers   

The study shows clearly that there are strong correlations between the level of air pollutant PM2.5 and low birth weight. The study also found that mothers who were underweight and of lower socioeconomic status were more vulnerable to exposure to air pollution.

Professor Hagai Levine, who initiated this study, said, "the governments need to set up the infrastructure to integrate environmental and health data at the personal level."

Furthermore, the study found that the association with air pollution was stronger among female babies and first births – a fact that is speculated to be the result of a biological mechanism that has yet to be identified.     

The association of air pollutants with low birth weight raises the question of whether the Israeli government should take the impact on developing babies into account and increase its efforts to reduce pollution.