Curious about climate-smart health – looking after our bodies and the planet

“Air pollution is the fourth most important risk factor when it comes to the global sickness burden,” says Petter Ljungman, a researcher in environmental epidemiology at the Institute of Environmental Medicine, who has conducted several studies on the impact of air pollution on our health.

Cars, flights and factories, the same eco-villains that emits carbon dioxide and contribute to the greenhouse effect, also emit particles that are bad for people’s health. Nitrogen dioxide content is also increasing, a problem for people with asthma in cities. In Sweden, nitrogen dioxide content has fallen sharply in recent years. To improve short-term health locally in Sweden, we probably mainly need to focus on combating particle content, despite these levels also having fallen significantly.

When we breathe in particles, it causes local inflammation in our lungs. The very smallest particles can make their way past the alveoli and out into other organ systems. Besides asthma, chronic obstructive pulmonary disease, lung cancer and lung inflammation, cardiovascular disease is strongly linked to air pollution. Twenty-five percent of all premature deaths from cardiovascular disease can be attributed to air pollution. Many of our chronic lifestyle diseases have common disease processes, such as low-grade inflammation. Air pollution also increases the risk of diabetes, premature births and dementia. The particles can get past the blood-brain barrier and into the brain.

“It is probable that air pollution also has an impact on the autonomic nervous system which controls the pulse, blood pressure and the gut,” says Petter Ljungman.

Stricter guidelines on air quality

The WHO recently issued new, stricter guidelines on clean air quality. For the smallest particles, the threshold was lowered from ten to five microgrammes of particles per cubic metre of air per year. According to the WHO, lower levels are better for health economics, and also benefit the climate.

Air pollution combined with high temperatures is a particularly bad combination for human health. In many parts of India, emissions are high, as are temperatures. Petter Ljungman is now heading up a major research project to find out how health is affected by the amount of exposure to emissions.

“We are using satellite data from NASA to produce a model that enables us to look back at emissions over time,” he explains.

The huge amounts of data to be analysed have led to the researchers calling in AI. The next step is to link the database to health cohorts to see how lung health and cardiovascular health have been affected depending on the level of exposure.

“The aim is to give decision-makers information so that they can make better decisions to reduce amounts of air pollutants, so improving health and reducing climate impact,” he says.

Petter Ljungman sees great benefit from talking about the link between climate and health.

“We have the health of the planet to think about, and the health of our fellow creatures and plants and then we have ourselves. But I think it’s a good thing to talk about health and the number of deaths because that makes it easier to calculate the economic consequences of a poor climate,” he says.

Compared with other parts of the world, Sweden’s levels of pollution are low. Particle content increases the further south you go.

“In Stockholm, the smallest particle levels are somewhere between 6 and 12 microgrammes per cubic metre. Levels are slightly higher in Malmö, around 8 to 15. Studies that I and my colleagues have conducted show that there is a higher risk of death and illness even at low levels,” says Petter Ljungman.

Children are especially vulnerable

With his colleagues, Daniel Helldén has brought together research to find out how children’s health is being affected around the world. He thinks it is remarkable how little research there is in this field.

“Children are especially vulnerable, both because their bodies are developing and because they are so dependent on other people,” he says.

It is clear that children living in better socioeconomic conditions are affected less than those who are already living in poverty and deprivation. This can already be seen in children’s health in low-income countries and in geographically vulnerable areas like strips of coastline or in the desert.

In the first wave of the pandemic, Mats J. Olsson and his team therefore took the opportunity to carry out a study on lifestyle changes to reduce greenhouse gases, to find out how the changes were affecting their quality of life. They asked people in the Stockholm region how well they had kept to the restrictions and calculated how much this meant in terms of reduced carbon dioxide emissions. Then they studied how much the individual had had to pay in the form of changed quality of life.

“The express ambition of the article was to specifically answer the question of which behavioural changes led to the greatest reduction in carbon dioxide in the atmosphere at the least psychological cost,” he explains. The result surprised him.

“We did see that the behavioural changes due to the pandemic in general had a psychological cost, in terms of quality of life, but in many cases this was not very high,” he says.

Not travelling for work and avoiding shopping and going to restaurants did not have a particularly negative effect on quality of life, while these behavioural changes had a major impact on reducing greenhouse gas emissions. On the other hand, many people felt badly about not being able to travel in their personal lives.

“Our findings may be interesting to every government or authority looking to draw up rules and policies on climate-friendly behaviour,” he says.

The participants in the study filled in the survey between the end of May and the beginning of August in the first wave of the pandemic.

Mats J. Olsson thinks that behavioural change can be an important element in halting climate change.

“But we need to know how to modify our behaviour in a climate context. We need to equip people with knowledge and give them opportunities to change their behaviour,” he says.

To succeed in motivating individuals towards behavioural change in different ways, he thinks that information will probably need to be adapted to different groups.

“Of course the fact that the effects of an individual’s behaviour are minimal on a global scale – and also at a distance in time and space – poses a particular challenge. But it is essential that we work on the climate question from different angles, not just through technical solutions,” he says.