Household air pollution (HAP) affects over 2.67 billion people worldwide and contributes to millions of deaths, according to a new study published in The Lancet as part of the Global Burden of Disease (GBD) 2021 project.

Although the percentage of people exposed to HAP has fallen by 56.7% since 1990, the absolute decline has been limited, just 0.35 billion (10%) from the 3.02 billion exposed that year.

Millions die from Household Air Pollution

More than 3.11 million deaths globally were attributed to HAP in 2021, the study reports. The researchers also attributed 111 million global disability-adjusted life-years (DALYs) to HAP, accounting for 3.9% of all DALYs.

DALYs (Disability-Adjusted Life Years) means the total years of healthy life lost due to illness, disability, or premature death.

The burden is particularly severe in sub-Saharan Africa and South Asia, where HAP-attributable DALYs remained highest, with 4044.1  and 3213.5 per 100,000 population, respectively.

The study also highlights that "HAP remains an important risk factor, with almost 30% of cataract burden and almost 20% of COPD burden due to HAP in 2021."

Women, children at greater risk

According to the study, people living in households using primarily solid fuels like coal or charcoal, wood, crop residues, and dung for cooking are exposed to high levels of HAP from particulate matter with a diameter of less than 2.5 µm (PM2.5), which is very hazardous to health. 

Women and children are particularly vulnerable. "Burns are common in households using solid fuels, and fuel collection typically falls to women and girls, consuming tens of hours per week," the study notes. 

More so the children under five who face severe risks. 

"More than 0.5 million deaths in children younger than 5 years attributable to HAP, highlighting that almost 11% of under-5 mortality is due to HAP," the researchers point out.

Progress undermined by population growth

Overall exposure HAP has been reduced in many countries but the progress has been undone  by rapid population growth in developing regions. "Declines in exposures were counteracted by population growth in most regions of the world, especially sub-Saharan Africa," the study reveals.

This, according to the study, has set back the achievement of the United Nations’ Sustainable Development Goals (SDGs). "UN Sustainable Development Goal (SDG) 3.9 aims to reduce morbidity and mortality from environmental pollution, and SDG 7.1 calls for universal access to cleaner fuels by 2030, but many countries still do not have the resources to achieve these goals," it says.

Reducing Household Air Pollution

The study calls for large-scale policy interventions and "continued investment in clean cooking solutions and targeted policies are essential to mitigate the long-term health risks of HAP."

"The shift away from solid fuels has not been fast enough to eliminate the health risks of HAP, and unless concerted efforts are made, it will continue to be a significant global health challenge," the study warns.

Also read: Indoor air pollution: How slum dwellers breathe air more toxic than others - First Check