Children born near oil, gas sites more likely to have heart defects
Children born to mothers living near oil and natural gas (O&G) sites are more prone to having congenital heart defects (CHDs), according to a recent study.
“[O]ur results and expanding development of O&G well sites underscore the importance of continuing to conduct comprehensive and rigorous research on the health consequences of early life exposures to O&G activities,” said researchers, adding that such an effect was stronger in rural areas than in urban communities.
In the study sample of 3,324 Colorado infants, 187 (median maternal age, 29 years) were born with aortic artery and valve defects (AAVD), while 179 (median maternal age, 27 years), 132 (median maternal age, 27 years) and 38 (median maternal age, 28 years) had pulmonary artery and valve defects (PAVD), conotruncal defects (CTD), and tricuspid valve defects (TVD), respectively. [Environ Int 2019;doi:10.1016/j.envint.2019.104949]
Accessing the Colorado Oil and Gas Information System, researchers found that most of the participants (59 percent; n=1,945) had medium exposure to O&G sites, while 25 percent (n=864) and 15 percent (n=515) had low and high exposure levels, respectively.
Logistic regression analysis revealed that medium (adjusted odds ratio [OR], 1.4, 95 percent CI, 1.0–2.0) and high (adjusted OR, 1.7, 1.1–2.6; p-trend=0.0230) O&G exposure during the second month of pregnancy significantly increased the risk of any CHDs relative to low O&G exposure.
Disaggregating according to CHD type showed similar effects for CTDs (medium: adjusted OR, 1.5, 0.87–2.6; high: adjusted OR, 2.0, 0.97–4.3; p-trend=0.0599) and PAVDs (medium: adjusted OR, 1.4, 0.87–2.3; high: adjusted OR, 1.7, 0.87–3.2; p-trend=0.1234), though trends failed to achieve statistical significance.
Place of residence appears to be a modifying factor for the interaction between O&G exposure and CHD risk. Children born to mothers in rural zip codes, for instance, were significantly more likely to develop any CHD after medium (adjusted OR, 1.6, 1.0–2.4) and high (adjusted OR, 2.4, 1.3–4.4; p-trend=0.0033) O&G exposure.
The same was true for AAVDs (medium: adjusted OR, 1.8, 0.97–3.3; high: adjusted OR, 2.6, 1.1–6.1; p-trend=0.00276), CTDs (medium: adjusted OR, 2.1, 0.96–4.5; high: adjusted OR, 4.0, 1.4–12; p-trend=0.0108) and TVDs (medium: adjusted OR, 3.4, 0.95–12; high: adjusted OR, 4.6, 0.81–26; p-trend=0.0846).
In contrast, “we observed no associations between O&G exposure and CHDs in births to mothers residing in an urban zip code,” researchers pointed out.
“[W]e suspect that both residual confounding and confounding from air pollution sources not considered in our study (eg, traffic related pollution and gasoline stations) may have obscured associations particularly in urban areas,” they explained.
Further studies are required to completely elucidate the biological mechanisms underlying the link between O&G exposure and congenital defects, researchers added.