Bad air might indirectly be a major culprit behind suicide-related spike, Chinese study finds

India, consistently home to many of the world's most polluted cities, continues to battle a daunting air pollution crisis that barely requires any introduction. In Delhi, pollution levels often soar past safe limits, sometimes eclipsing nearly 20 times the World Health Organisation's recommended guidelines.

More than just a straightforward impact on the residents' physical health, scientists have always worried that the toxic smog could be finding its way to our brain and altering its chemistry, effectively impacting our mental well-being as well. And now, a new study might just have confirmed these concerns.
Pollution down, suicides down
Just like India, China shares in the notoriety for its heavily polluted cities. However, the launch of air pollution mitigation policies helped the nation achieve something expected: a sizeable decline in suicide rates. While factors like rising incomes and cultural shifts likely contributed, a new study has exposed the first significant link between air quality improvements and suicide prevention.

China launched its ambitious Air Pollution Prevention and Control Action Plan in 2013. This plan tackled industrial emissions and vehicle pollution, and focused on the country’s transition to cleaner energy sources like natural gas and renewables.

The plan's success quickly became evident in both improved air quality and declining suicide rates. Between 2010 and 2021, the annual suicide rate dropped by over 50%, from 10.88 to 5.25 per 1,00,000 people. These findings align with previous research suggesting fine particulate matter — PM2.5 in particular — can directly affect brain chemistry and mental health, potentially leading to emotional dysregulation and suicidal ideation.

In fact, researchers estimate that roughly 10% of China's recent decline in suicides can be attributed to improved air quality. This translates to nearly 46,000 suicide deaths prevented between 2013 and 2017 due to the clean air initiative. It may also be important to note that while there was a clear spike in suicide rates following bad air quality events, this effect did not persist beyond a week.
India’s struggles with air quality and suicides
While the study focuses on China, its findings are quite relevant worldwide and especially to our country. Data from the Global Burden of Disease showed that India's annual average PM2.5 exceeded the WHO's safe limit by a whopping 16 times in 2019.

Meanwhile, suicide rates seem to be on the uptick in India as well. NCRB and Lancet study data showed that the country reported the highest number of suicides in the world in 2021.

Since then, several studies have examined the public and health burden of poor air quality on Indian residents. A 2022 Lancet study linked pollution to 2.3 million premature deaths in India in 2019. However, research directly correlating suicide rates with the country’s pollution woes remains non-existent, and thus, no clear connection can be drawn at the moment.

Nevertheless, India has also launched initiatives to combat air pollution, including the National Clean Air Programme (NCAP) aimed at reducing PM2.5 concentrations by 20-30% by 2024. While progress has been made, significant efforts are still needed to achieve clean air, potentially leading to positive impacts on public health, including overall mental well-being.

"While there remain many open questions regarding the connections between air quality, mental health and suicide, this analysis adds urgency to calls for pollution control policies across the globe," the paper reads.

The findings of this research have been published in Nature Sustainability and can be accessed here.