Study finds air pollution increases suicide risk and depression

By Sarah MooreDec 18 2019

Cutting air pollution could significantly reduce global rates of depression, a new study finds. Scientists at UCL have collected data from 16 countries, and in a paper published this week in Environmental Health Perspectives they describe how higher levels of air pollution have been found not only to be related to elevated rates of depression and suicide, but that it is likely a causal factor.

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The detrimental impact of air pollution

Recent years have seen rising concerns around the impact of air pollution on the environment, human health, and now, new research has raised the alarm that it is also detrimental to our mental wellbeing. The World Health Organization (WHO) recommends that ten micrograms of ultra-fine particles (air pollution) per cubic meter is the limit to what should be considered safe.

However, there is growing fear that the EU and UK’s limit of 25 micrograms per cubic meter, 2.5 times the safe limit recommended by the WHO, is putting people’s health at risk.

Numerous studies have already proven that air pollution is a causal factor in the initiation of several diseases, such as lung cancer. Research has also uncovered that air pollution is one of the world’s top 10 major risk factors for attributable death.

Furthermore, air pollution is related to impaired immune-system and cognitive development in children, as well as being a contributing factor to the deaths of half a million children under five each year who develop respiratory tract infections. Further to this, air pollution is known to increase the risk of heart attacks in certain populations.

Overall, the data is mounted, which demonstrates the real danger posed by air pollution. Now, new evidence has come to light that proves its role in mental health. It has previously been established that some neuropsychological problems can be worsened by air pollution, such as dementia. But now, a study conducted by researchers at UCL has confirmed its role as a causal factor in depression and even suicide.

Rising air pollution linked with increased risk of depression and suicide

Dr. Isobel Braithwaite, the study’s lead author, explains that an increase of 10 micrograms of fine particulate matter (PM2.5) per cubic meter of air can lead to an increase in the risk of depression. People experiencing these levels over long periods were found to be 10% more likely to suffer from depression.

The team also found that the levels of risk posed to mental health were comparable to those posed to physical health. Worryingly, the team also saw that in days which followed three-day periods of high PM10 levels, there were measurably more suicides, relating risk of suicide to increased levels of air pollution.

The data indicate that these figures are not related to neighborhood or socioeconomic factors, strengthening the case for pollution directly impacting mental health, although more evidence is needed to confirm causal mechanisms.

However, it was calculated that for each ten microgram increase in particles per cubic meter, over a three-day period, the risk of suicide rises by 2%. These findings are significant in flagging the danger that air pollution poses to mental health and even mortality.

Tackling air pollution to address mental health

While more studies are needed to explore the nature of the relationship between depression, suicide, and air pollution, the data already strongly indicates that air pollution is a causal factor in both. This information is incredibly important for informing governments of the urgency of tackling air pollution.

In addition to the known physical impact, there is mounting evidence to describe its impact on mental health. Depression and suicide may not be alone in their links with air pollution. Given that the mechanisms of these relationships are yet to be fully understood, it is reasonable to assume that other mental health problems, such as anxiety, may also be influenced by air pollution.

Future regulations regarding emissions, particularly of cars, will likely be influenced by this data, hopefully resulting in the reduction of the “safe” limit, having the impact of protecting people’s physical and mental wellbeing.