Getting things in the right perspective

The coming UK national election will inevitably be dominated by Brexit, at least for most voters. But this is not the only concern and in itself will have a knock-on effect on other issues for which policy currently emanates from Brussels. Not least among these is the environment in its broadest sense, with policy on air and water pollution, farming (including pesticides), wildlife conservation etc all being made at EU level.

With the UK’s relationship with other EU member states inevitably changing, the Westminster parliament may once more be able to introduce policies designed with the interests of the country in mind rather than being obliged to obey regulations or enact directives agreed centrally.

With the exact form of the divorce settlement not yet clear – and unlikely to become any clearer for some time given the inevitable posturing and hardening of public positions on both sides – we cannot know how far this freedom will extend in practice. Even in the unlikely event of the hardest of exits, with no deal having been struck, the UK will need to adhere to some EU environmental standards in order to export. We should also recognise that a lot of environmental legislation is good for all of us; no-one wants to reverse the great improvements made in air and water quality in the last 50 years, for example.

But the devil is in the detail. Having achieved great things, there is continued momentum to make more improvements. The vast reduction in deaths from infectious illness made possible by antibiotics and vaccines has focussed ever more attention on other problems. Far more people now survive long enough to die from a heart attack or cancer, and modern lifestyles have fostered the current curse of obesity and type 2 diabetes. We take for granted the continuing increase in life expectancy while worrying instead about the problems of non-communicable and degenerative diseases.

As for health, so for the environment. But there is one big difference: with the exception of the continued threat to certain species from pressure on habitat, there are no big new problems that have emerged as the key issues associated with pollution have been tackled. Nevertheless, we hear almost daily reports of problems, including air quality and the currently dominant topic of climate change.

Most of these issues are very polarised and emotive and unfortunately not often amenable to rational discussion. Take air pollution, for example. Clearly, urban air is by many measures far cleaner than it used to be. When wood and coal were used for heating and cooking, smoke would have made city air much less pleasant and have posed a significant health risk. This is the same risk now borne by poor people in developing countries, with the burden falling primarily on women and children.

Just over a century ago, horses were still the prime locomotive force in London, with most journeys being undertaken by foot. During the 1910’s, there was a rapid change to motorised public transport, which from then on would have contributed to air pollution. But the predominant black of London’s buildings was from the soot of the ubiquitous coal fires. Smog was common, but it was only after the Great Smog of 1952 that the first serious attempt was made to reduce pollution with the passing of the Clean Air Act in 1956.

Removal of the then dominant source of air pollution eventually served to draw attention to the problem of vehicle exhausts. Over time, lead was removed from petrol and a series of tightening (EU) standards produced engines with cleaner and cleaner exhausts. Despite that, we are currently exercised by the remaining problem of fine particulates (PM2.5) emitted by older generations of diesel engines and the more recent awareness of the ongoing issue of NOx emissions.

The result is a scramble to keep diesel cars out of cities, based largely on the headline figure of particulate and nitrogen oxide pollution being a contributory factor to 40,000 premature deaths annually. This is not the place to delve deeper into the evidence for this apparently shocking figure, but suffice it to say that about three quarters of the excess mortality is the result of particulate pollution, now effectively eliminated by the latest generation of diesel engines. The Euro 6 standard also cuts NOx down to close that of petrol engines.

In an ideal world, we would wish for pristine clean air everywhere, but this is rarely the case, even in rural areas (many small particulates are formed naturally, for example). If PM2.5 and NOx emissions from vehicle emissions were eliminated, tyre wear and brakes would continue to release particulates and gas heating would continue to pump considerably more NOx into the air than cars do now. Improving air quality in cities needs a thorough rational analysis, first to quantify the real impact, second to define practical, acceptable limits and third to devise least cost ways to achieve them. We need to get a clear perspective on the issues and achieve a satisfactory balance between the pros and cons of urban life.

In similar vein, pesticides have come under increasing pressure because of the supposed harm they cause and the hypothetical hazard they pose. No matter that application levels and usage patterns are such that barely more pesticides are detected on ‘conventional’ produce that their ‘organic’ equivalents, the perception by a largely scientifically illiterate public is that pesticides are intrinsically bad.

Most attention from campaigners is currently focussed on neonicotinoid seed treatments, (which have been blamed for declines in bee populations despite no hard evidence of harm in practice) and glyphosate weedkiller, which is being targeted as a human carcinogen. To quote Bruce Ames yet again, “There are ten milligrams of known carcinogens in a cup of coffee and that’s more carcinogens than you’re likely to get from pesticide residues for a year.” This is another area where a more balanced perspective is called for, taking account, for example, of the estimated 40% of global harvests made possible by the use of pesticides.

With the government’s attention fixed on Brexit for at least the next two years, it is unrealistic to expect any changes to policies in such areas for a while yet. But maybe, just maybe, it’s reasonable to hope for a more balanced view in years to come. Looking at real risks and their management rather than hypothetical hazards would be a start. Balancing risks and benefits would be even better.