As opening gambits go, it’s not a very appealing one, but I want to talk about muck spreading. This agricultural practice, wrapped up in childhood nostalgia of quickly winding up windows on countryside drives, seems innocent and natural enough. It helps grow the food we eat and produce the milk we drink.

Less homespun and not so well-known though, is that muck spreading contributes enormously to air pollution, even in London, which couldn’t be any further from its rural hinterland when you’re stuck in traffic on the A2.

But it does. So much so that 20 per cent of the pollution particles in UK cities is caused by agricultural emissions. The main culprit is ammonia emissions (coming primarily from chemical fertilisers and manure and slurry from livestock) which, when emitted, reacts quickly with other air pollutants to create tiny particles which can travel large distances and cause damage in areas and countries which are thousands of miles away.

These tiny particles are so small – approximately 1/30th the average width of a human hair – that they are able to penetrate deep into our lungs and even our blood system. This has alarming consequences for our health, and has been linked with heart and lung disease, an array of cancers, asthma, diabetes, reduced growth in children’s lungs, low birth weights, and ageing of the brain.

While British farmers undoubtedly cause some of this pollution, over a third of it is blown in from farms on the continent – from Poland, Germany, France, and the Benelux countries. In fact the problem is so prevalent, that new research has found the smog episodes that periodically hit London are not principally down to Saharan dust, but instead are the result of the more modest practice of European farmers spreading muck on their fields.

The upshot of all this – if Britain is to truly solve the air pollution crisis blighting our towns and cities – we need farmers in neighbouring countries to fundamentally change the way they spread muck. To do this effectively, we must be inside the European Union to ensure common targets and standards are set for all.

I want to make it absolutely crystal clear it’s not all the farmers fault. All sectors must play their part. We need cars to spew out less pollution, energy providers to move towards cleaner, more sustainable methods of energy production, and manufacturing industries to adopt more efficient methods of production.

In all of these cases, action at a European level is crucial. Our EU membership gives us influence over our European neighbours, enshrines co-operation, and stops a race-to-the-bottom on environmental standards.

If we left the EU and wisely ignored the economic folly of leaving the Single Market, we would also almost certainly still be subject to new rules, but would have absolutely no power to influence them.

For instance, we have emissions standards, no matter how fallible they currently are, that apply to all cars that car manufacturers want to sell on the EU market. This stops companies gaining a competitive edge by reducing costs and putting more polluting vehicles on the road. I’m currently leading the Socialist and Democrat Group on the European Parliament’s inquiry into the dieselgate emissions scandal to see how these rules can be beefed up and lessons learnt.

In anticipation of comments from the broadband bully-boys of the Leave campaign, I’m not claiming that European action is a silver bullet to all of Britain’s air pollution problems (although unlike me driving through the Rotherhithe tunnel, I won’t hold my breath that many of them have actually read this far).

Of course, action at the national and local level is absolutely crucial. But what Europe provides are national targets that set a positive direction of travel that, we all hope, will end with the elimination of the UK’s biggest public health issue estimated to cost the NHS some £20 billion every year.

Since being elected, I have been working tirelessly on the National Emissions Ceiling Directive, an extraordinarily boring sounding but crucial bit of air quality legislation that will set national limits on every EU Member State on the toxic emissions that, put crudely, kill the most people. It could cut the annual number of deaths caused by air pollution in half by 2030. That figure currently stands at 40,000 in the UK alone and rises every time a new study emerges.

Progress has been slow going though, with negotiations currently bogged down after the UK government put its significant weight in the Council behind efforts to lead a ‘coalition of the unwilling’ between Member States, opposed to ambitious new rules that would prevent more air pollution-related deaths. See, there is such a thing as UK sovereignty inside the EU!

Despite these setbacks, the environmental case of voting to Remain is compelling. Air pollution cannot be stopped at Calais. By staying inside the EU we can continue to work with and hold sway over our partners and better confront the big environmental challenges that will continue to afflict our shores.

Seb Dance has been a Member of the European Parliament for London since 2014, and serves on the European Parliament’s Committee on Environment, Public Health and Food Safety.