Environmental variables influence mortality risk
A new study reveals that environmental variables like air pollution, together with high blood pressure, diabetes, and smoking, are highly predictive of people’s risk of dying, particularly from heart attack and stroke.
The study, conducted by experts from the Icahn School of Medicine at Mount Sinai and the New York University Grossman School of Medicine, revealed that exposure to above-average levels of outdoor air pollution increased the risk of mortality by 20% and the risk of death from cardiovascular disease by 17%.
Cooking on wood or kerosene stoves that aren’t adequately vented via a chimney increases the risk of death overall (by 23% and 9%, respectively) and the risk of cardiovascular death (by 36% and 19%). Living close to busy roads and distant from specialized medical clinics also raises the likelihood of death.
The results, which were recently published in the journal PLOS ONE, were based on personal and environmental health data gathered from 50,045 rural villagers, most of whom were impoverished, who lived in Iran’s northeastern Gulistan region. All study participants were older than 40 and consented to yearly visits with researchers beginning in 2004 to have their health evaluated.
Researchers claim that their most recent investigation adds much-needed scientific evidence from people in low- and middle-income nations, as well as identifying environmental factors that are most harmful to the heart and general health. The researchers point out that traditional research on environmental risk factors has favored urban people in high-income nations because they have much easier access to modern health care facilities.
Compared with those who have easier access to specialized medical services, those living farther away from clinics with catheterization labs able to unblock clogged arteries, for example, were at increased risk of death by 1% for every 10 kilometers (6.2 miles) of distance. In Gulistan, most people live more than 50 miles (80 kilometers) away from such modern facilities.
Study results also showed that the one-third of study participants who lived within 500 meters (1,640 feet) of a major roadway had a 13% increased risk of death.
“Our study highlights the role that key environmental factors of indoor/outdoor air pollution, access to modern health services, and proximity to noisy, polluted roads play in all causes of death and deaths from cardiovascular disease in particular,” says study senior author and cardiologist Rajesh Vedanthan, MD, MPH.
“Our findings help broaden the disease-risk profile beyond age and traditional personal risk factors,” says Vedanthan, an associate professor in the Department of Population Health and the Department of Medicine at NYU Langone Health.
“These results illustrate a new opportunity for health policymakers to reduce the burden of disease in their communities by mitigating the impact of environmental risk factors like air pollution on cardiovascular health,” says study lead author Michael Hadley, MD, a fellow in cardiology and incoming assistant professor of medicine at Mount Sinai.
By contrast, the study showed that other environmental factors included in the analysis — low neighborhood income levels, increased population density, and too much nighttime light exposure — were not independent predictors of risk of death, despite previous research in mostly urban settings suggesting otherwise.
For the investigation, researchers analyzed data gathered through December 2018. They then created a predictive model on overall death risk and death risk from cardiovascular disease.
The research team plans to continue its analysis and hopes to apply the predictive model to other countries with the aim of fine-tuning its predictive capacity. They say their new tool could serve as a guide for evaluating the effectiveness of environmental, lifestyle, and personal health changes in reducing mortality rates worldwide.
According to the World Health Organization, one-quarter of all deaths worldwide are now attributable to environmental factors, including poor air and water quality, lack of sanitation, and exposure to toxic chemicals.
Reference: “Spatial environmental factors predict cardiovascular and all-cause mortality: Results of the SPACE study” by Michael B. Hadley, Mahdi Nalini, Samrachana Adhikari, Jackie Szymonifka, Arash Etemadi, Farin Kamangar, Masoud Khoshnia, Tyler McChane, Akram Pourshams, Hossein Poustchi, Sadaf G. Sepanlou, Christian Abnet, Neal D. Freedman, Paolo Boffetta, Reza Malekzadeh and Rajesh Vedanthan, 24 June 2022, PLOS ONE.
Funding for the study was provided by US National Institutes of Health grant R21HL140474.