The hidden effects of pollution

The hidden effects of pollution are affecting our daily lives – in ways we can’t yet fully measure.

On 5 June the UN Environment Programme (UNEP) marked World Environment Day. Held every year since 1974, the campaign seeks to raise awareness of environmental issues and encourage global action.

Campaigns like this one naturally focus on the undeniable evidence of climate change: rising temperatures, wildfires, floods, droughts. These incidences, which are growing in number and magnitude across the world, show that urgent change is needed.

In the UK, though, where extreme weather is (for now, at least) less common; where heat waves are still, for the most part, enjoyed rather than dreaded, it’s easy to feel detached from the impacts of our damaged environment.

More so when we see the worldwide statistics. Data from UNEP shows that, as a nation, the UK is (just about) keeping air pollution levels at an acceptable limit, and has achieved, or is on track to achieve, most of its environmental targets. It can seem as though the destructive effects of pollution are knocking at the door, but haven’t yet been invited in.

In fact, our polluted environment is already damaging our health, our education and our economic prospects. And because these effects aren’t always easy to identify, we don’t have a clear measure of their true extent.

Take lead pollution. Lead is a naturally occurring, but toxic, metal. Over the years, widespread use of lead in everyday items such as petrol, paint and pipes has increased our levels of exposure to it. While nowadays the use of lead is strictly regulated, the effects of its historic use linger.

Lead poisoning is particularly harmful to children. It affects educational achievement: Levels of lead in the blood of 5μg/dl is thought to reduce a child’s IQ by 3­–5 points. Lead-poisoned children are also prone to more reckless behaviour and even violence. As a result, they often achieve lower school grades than their peers.

Much of the evidence on the effects of lead poisoning comes from countries like the US, where screening is widespread. In the UK, known cases of lead-poisoning are low, but that is because blood lead levels are not routinely screened. The National Screening Committee decided against routine screening in 2018 partly because the number of affected children is not known. They are due to review that decision this year.

Lead poisoning doesn’t just cause a risk to children’s health. There are further, hidden, effects. The classroom disruption caused by children with high blood lead levels can have a spillover effect on their peers. Recent research by CAGE Theme Leader Ludovica Gazze, with Claudia Persico and Sandra Spirovska, shows that children who go to school with lead-poisoned students are more likely to be suspended and are less likely to take college entrance exams. This in turn affects their earnings. The damaging effects of lead-poisoning are wide-reaching and can last a lifetime.

Dr. Gazze’s research focuses on data collected in North Carolina in the US. In the UK, the full impact of lead poisoning in children is unclear. Unicef estimates that over 200,000 children over the age of five in the UK could be at risk from lead poisoning. Given the effects on class peers found in Dr. Gazze’s analysis, the impact on children’s educational outcomes and future economic prospects could be much larger.

And the overall economic costs to the country could be huge. Dr. Gazze estimates that the spillover effects of lead poisoning in the US could be as much as $8 or $9 billion a year.

So, while it might seem that we’ve so far escaped the most extreme impacts of pollution in the UK, in fact we’re already paying a high price for our past environmental choices. What’s worrying is that we are only just scratching the surface in terms of understanding the extent of the damage we’ve caused.

Stephanie Seavers, Communications Manager, CAGE

Find out more

Ludovica Gazze, Claudia Persico and Sandra Spirovska, (2021). The long-run spillover effects of pollution: How exposure to lead affects everyone in the classroom. CAGE working paper (561).

Ludovica Gazze (2021). Exposed: the widespread societal costs of lead contamination, Advantage, Issue 12 (Climate Change and Pollution Special), CAGE: University of Warwick.