A sketchy diagnosis

The title of the latest report from the UK chief medical officer is ‘Health Impacts of All Pollution – What Do We Know?’. As it turns out, it seems we know very little, writes David Burrows

The UK’s chief medical officer has just published her assessment of the health impacts of pollution. “There are no aspects of our life that do not have the potential to be impacted by pollution,” says Professor Dame Sally Davies in her foreword. The report covers everything from noise pollution outside schools and the air quality in our cities to pharmaceutical pollution and the growing use of nanoparticles – one of several so-called ‘21st-century chemicals’.

The newspapers have been homing in on risks from your smartphone. Davies told BBC’s Today radio programme that the light from your mobile at night won’t kill you, but that she’d turn the device over or off. “There are pollutants; it’s part of our economic activity … but we need to get the right balance,” she said. “What is a reasonable risk the public should take? A lot of the time we don’t know enough.”

I skimmed through the report to the bits I was interested in – microplastics and agrochemicals, two of the pollutants that are ‘low level’ in terms of exposure, but about which little is known regarding long-term effects. Indeed, Davies said she was struck by the lack of evidence. Others voiced similar concerns. Professor Alistair Boxall, from the University of York’s environment department, co-led the development of a chapter in the report on the potential health effects of the cocktail of emerging chemical pollutants, such as nanomaterials and natural toxins, as well as of the physical pollutants that all people are exposed to. “We are all aware of the health effects of traditional pollutants,” he says. “However, throughout our lives, we will be exposed to many more chemical and physical pollutants, in the air we breathe, the water we drink and the food we eat. Our understanding of the impacts of many of these on human health is poor.”

Microplastics and agrochemicals certainly tick those boxes. They are the kinds of pollutants that have slipped under the radar in the past – something Davies alludes to in her summary when she says we think of pollutants as “rapid poisons” but that this isn’t the case. In fact, many pollutants are risk factors for a range of non-communicable diseases. “We need to investigate the longer-term impacts of lower-level pollution exposure,” she says.

“The clarion call from this report is to create systems to monitor, understand and act on data about the health impacts of pollution”

There are just six paragraphs on microplastics in the report, the upshot of which is: “More work on the potential for human health effects is required.” That much we already knew. The European Food Safety Authority (EFSA) has said as much, and the UK’s Food Standards Agency has, unsurprisingly, agreed.

How about agrochemicals, then? As with microplastics, these pollutants have been in the news in recent months, mostly thanks to glyphosate, the world’s most widely used weedkiller. There’s been a transatlantic spat between the International Agency for Research on Cancer (IARC) and EFSA: the former claiming the chemical is probably carcinogenic to humans, but the latter believing that’s unlikely to be the case. However, EFSA’s evaluation is under scrutiny by PEST, a committee set up by the European Parliament, which will assess whether Monsanto – which sells glyphosate as Roundup – influenced the outcome.

The CMO’s report mentions glyphosate in passing, as an example of how differences of opinions between agencies “can lead to public confusion”. However, the feeling was that the use of other agrochemicals is likely to increase as the climate changes and disease and pest pressures change. So global warming is good news for the likes of Monsanto but potentially not so good for human health.

All this leaves us with more questions than answers. “At the moment, we do not have the systems in place to effectively monitor, understand and act on data about the health impacts of pollution,” says Davies. “The clarion call from this report is therefore to create these systems so that we can determine effective actions.”

Meanwhile, the government’s ‘Future of the Sea’ report has landed in my inbox. The amount of plastic in the ocean is set to treble in the next 10 years, the authors warn. But while plastic is high-profile, it’s not necessarily the greatest threat – there’s also chemical run-off from farms, industrial toxins and pharmaceuticals. The government certainly has its work cut out – and yet its 25-year environment plan fails to even mention the word ‘pollution’.

David Burrows is a freelance journalist