Patrick Brown | New Delhi
As air pollution intensifies across South Asia, the region is grappling with an alarming rise in lung cancer cases, a crisis exacerbated by climate change.
Home to 37 of the world’s 40 most polluted cities, South Asia sees even non-smokers increasingly at risk, with mortality rates among lung cancer patients climbing.
A recent Lancet study underscores the urgent need for comprehensive measures to address this escalating public health emergency.
“As climate change continues to unfold, it magnifies the burden of lung cancer, which is already a significant public health challenge in Asia,” the study notes. “The continuing rise in lung cancer cases and deaths projected by 2040 is not just a matter of statistics. With the climate crisis, it underscores the pressing need for proactive measures.”
According to the Cancer Tomorrow online tool of GLOBOCAN, the estimated number of new lung cancer cases in Asia is expected to be 2.1 million, with an estimated 1.9 million deaths by 2040. This represents increases of 64.1% and 72.8%, respectively, from 2020.
The physical impacts of climate change, such as flooding and extreme weather events, can disrupt healthcare infrastructure and care delivery. This disruption may lead to delays in diagnosis, treatment initiation, and continuation of care, impacting overall patient outcomes. The climate-related threats and the pressing challenges of lung cancer underscore a health crisis in Asia.
Almost one million people aged 60 and older were diagnosed with lung cancer in Asia in 2020. Older individuals with lung cancer are more vulnerable to the adverse effects of extreme heat, which can exacerbate respiratory symptoms, increase the risk of dehydration and infections, limit mobility, and create difficulties accessing medical care during heatwaves.
In 2013, the International Agency for Research on Cancer (IARC) officially classified air pollution as a carcinogen. Elements within polluted air, such as nitrogen dioxide, sulphur dioxide, ozone, and particulate matter (PM10 and PM2.5), have carcinogenic properties.
In South Asia, regional PM2.5 concentrations have remained persistently high, with population-weighted annual PM2.5 concentrations in countries like India, Nepal, and Bangladesh reaching peak levels in 2020. Particulate air pollution alone is responsible for up to 15% of all lung cancer fatalities, with the mortality rate linked to particulate pollution surging by 20% over the past three decades.
The past eight years, from 2015 to 2022, have been the warmest on record. Global warming, mainly due to rising greenhouse gas concentrations (carbon dioxide, methane, and nitrous oxide) in the Earth’s atmosphere, is a major driver of climate change. Human activities, such as burning fossil fuels for energy production and transportation, deforestation, industrial activities, agricultural practices, and waste management, are primary contributors to global warming.
Consequences of global warming include melting ice caps and glaciers, rising sea levels, shifts in weather patterns, more frequent and intense heatwaves, and changes in ecosystems and biodiversity. The harmful effects of climate change are increasing and spreading, making it the biggest global health threat of the 21st century.
“The threat of climate change poses significant challenges for patients with cancer, exacerbating existing health risks and complicating treatment pathways,” the study adds. “While climate change itself does not directly cause lung cancer, several interconnected elements contribute to an increased risk and impact on care.”
