90% of brain development happens by the age of four, so scientists want to understand the effects of air pollution at the earliest stages of life.
Barcelona as an example
Between 1981 and 1989, 26 outbreaks of asthma were reported in the Spanish city with many cases centred around the harbour. Local scientists eventually discovered that the cause was soybean dust released into the air when the cargo was unloaded.
The solution was simple enough – filters to cover the soybeans silos – however, the episode left a remarkable legacy in the scientific community in Barcelona, which could help us to identify a significant risk to brain development in children.
The asthma epidemics were initially thought to be due to air pollution from burning fossil fuels, so the researchers created a register to map its potential impact. This became the basis for the local researchers to continue to monitor the effects of dirty air over the decades since.
Professor Jordi Sunyer from ISGlobal, the Barcelona Institute for Global Health, was one of the researchers who discovered the link to soybeans and investigates the effects of air pollution.
‘In the 80s, home combustion of coal was a major problem, and the levels of sulphur oxide were very high. This was controlled but now, especially in Europe, there is a dramatic increase in traffic and diesel combustion,’ he said.
When the lead pollution from petrol was found to be causing widespread harm, unleaded petrol was introduced from the 1970s. At an individual level, a 5% decrease on a test would not be enough to make an obvious impact, but on a population level it could have a significant economic cost says Prof. Sunyer.
He is leading the AIR-NB study to monitor the exposure to air pollution before the child is even born. The research team is recruiting 1,200 pregnant women in Barcelona to the study and measuring the pollution levels in their homes.
Another concern is that air pollution can raise the risk of developing autism spectrum disorder. Several studies in the US suggested that there is a link to air pollution, but the results from a big European project found no connection. However, this research brought together results from different studies that used different methods, which may have affected the results.
For a project called COGNAC, Dr Delgado-Saborit is using health information collected on the children up to the age of 14 to look for diagnoses of autism spectrum disorder or traits of the condition. By overlaying this information with maps of pollution during pregnancy and in their early years, she hopes to identify any potential links.
Just like the 1950s, there is widespread understanding today that our dirty air is not safe, but we still do not know how great an impact it has on our lives. While there is acceptance that children at school should not be exposed to high levels of air pollution, Prof. Sunyer says, the results of their research could have far-reaching consequences:
‘If we found pregnancy and early life is a more vulnerable period, I think this would force society to find new ways to live in cities that also protect the health of children.’
However, compared to putting a lid on soybean dust, this may prove to be a big challenge.