Air quality has a huge impact on children’s development. In Los Angeles, one of the most polluted cities in the West, the problem is being tackled in a way that other cities can learn from.

Frank Gilliland is a researcher of medicine and air pollutants at the University of Southern California in Los Angeles, an idyllic campus surrounded by leafy forest and tall palm trees. However, just a few blocks away, you are hemmed in by the freeways typical of southern California. For a long time, Los Angeles was the city with the worst air pollution in the US. A thick blanket of yellow-brown smog often settled over the city in the afternoons, which meant that disappointed tourists could not even see the famous Hollywood sign high above the city. But over the past two decades, the city has really got to grips with pollution. One of the driving forces was to protect the millions of children who grow up in the metropolitan area of Los Angeles.

“Many children had respiratory problems and stinging eyes but, above all, our research showed that air pollution affects children’s long-term development. It increased the risk of asthma and had a negative effect on their mental capacity,” Gilliland says. Based on his research, among other things, the local authorities in Los Angeles imposed stringent rules to clamp down on emissions and pollution. They focused primarily on road traffic and the ports of Los Angeles and Long Beach, the biggest cargo shipping complex in the US. The authorities also banned the burning of wood when the air in Los Angeles was particularly bad. Ten years later, the proportion of children with asthma in areas with heavy air pollution had gone down by 30-40 percent. “Asthma is associated with many other problems for children. It leads to them exercising less, which increases the risk of pathogenic obesity. In turn, a lack of exercise leads to them learning less and developing more slowly. It also increases the risk of diabetes,” Gilliland says.

“Moreover, the poor air makes them ill and children learn less if they are ill. We have seen that there is a link between poor air and more children staying home from school. This is detrimental both to children and their parents who have to stay home from work. Additionally, there is more and more research that has shown poor air and pollutants increase the risk of neurological problems and autism. A young brain is extremely sensitive and poor air damages children across the whole spectrum, from the brain to the lungs, and it is hard to recover from harmful effects on the brain at that age. You don’t get a second chance.”

When it comes to road traffic, Gilliland says there’s reason to be optimistic and notes the trend towards more eco-friendly cars. “We succeeded in reducing pollution in Los Angeles at the same time as road traffic increased dramatically, by almost 80 percent. That was partly because we controlled other emissions, partly because we are moving towards more eco-friendly cars and lorries. A young brain is extremely sensitive and poor air damages children across the whole spectrum."

What should parents keen for their children to breathe air that’s as clean as possible do?

“All pollutants caused by road traffic are particularly harmful so parents with small children should try to stay away from major roads. Above all, parents must play an active role in local politics and push for changes to improve air quality. There must be more political pressure. In the short term, they can also use air purifiers in their children’s bedrooms and keep windows closed on days when the air quality is poor.” California is home to a lot of this sort of technological innovation. Another area where Gilliland sees a promising trend is technology for measuring pollutants and air quality in our everyday lives. “It is becoming cheaper and easier for people to measure air quality in their own homes,” he says. “New products connected to the internet can help generate data on pollutants in a whole housing area, in real-time. When we have access to more information and better data on pollutants and their effects, it will hopefully lead to more preventive measures and more local activism to improve air quality. It should be a human right to breathe healthy air.”