Separate research shows two new medical issues exacerbated by air pollution

Separate research, published a couple of days apart, has identified two new areas of concern in terms of the affect of poor air quality on people’s health.

In Barcelona, a study that is part of a collaborative project to assess the health impact of the Covid-19 pandemic on the Catalan population has found that poor air quality is linked to lower Covid-19 vaccine responses. 

Because it is known that poor air quality can affect immune responses, a team led by the Barcelona Institute for Global Health set out to discover whether it also affected antibody responses to the COVID-19 vaccine. 

Using an established cohort of 927 people aged between 40 and 65, the team had access to ten years of data through which they could establish how exposed the participants had been to PM2.5, black carbon, nitrogen dioxide and ozone. 

The participants gave blood samples in the Summer of 2020 and again in the Spring of 20221, after the vaccine programme had been rolled out. The results showed that in uninfected individuals, pre-pandemic exposure to PM_2.5, NO₂ and BC was associated with a 5% to 10% reduction in vaccine-induced antibodies.

Carlota Dobaño, co-senior author of the study, together with Cathryn Tonne said: ‘Air pollution can induce chronic inflammation, which has been associated with a negative effect on vaccine efficacy. Our findings are consistent with evidence that persistent organic pollutants reduce vaccine responses in children.’

Meanwhile in the US, a team from the Harvard T.H. Chan School of Public Health have found that exposure to PM2.5 may increase the risk of developing dementia. Using new research tools (active case ascertainment and a new, more powerful bias assessment tool) they found consistent evidence of an association between PM2.5 and dementia, even when annual exposure was less than the EPA annual standard of 12 μg/m3.

In particular, among the studies using active case ascertainment, the researchers found a 17% increase in risk for developing dementia for every 2 μg/m3 increase in average annual exposure to PM2.5. They also found evidence suggesting associations between dementia and nitrogen oxide (5% increase in risk for every 10 μg/m3 increase in annual exposure).