Children’s Health: Vehicle Emissions

Baroness Bull Excerpts

Tuesday 11th June 2019 Lords Chamber

[Baroness Bull (CB)]

My Lords, it is a pleasure to follow the noble Baroness, Lady Blackstone. I congratulate the noble Baroness, Lady Randerson, on securing this important debate.

It is estimated that poor air quality is the cause of up to 40,000 premature deaths in the UK every year, with air pollution reducing life expectancy in those affected by an average of 11 years. Nevertheless, there is scant awareness of the scale of the problem. Air is a vital source of life on our planet, but it is fast becoming the health crisis we failed to see. Air pollution is bad news for all of us, but is especially so for children because of the juvenility of their brains and respiratory systems. As we have heard, children have a higher breathing rate to body size ratio and spend more time outdoors, both of which put them at even greater risk from exposure to polluted air.

The link between air quality and physical health is well established, with air pollution associated with a range of conditions that include cardiovascular and respiratory disease. However, new research is now demonstrating a link between air pollution and mental health. It has been several decades since the higher rates of schizophrenia in the inner city, relative to the outskirts, were first documented. Research undertaken since then has found that urban upbringing is associated with a twofold risk of psychiatric disorder in adulthood. Most studies have focused on the social features that might contribute to this elevated risk, which leaves a key feature of the urban environment underresearched. I am talking, of course, about air pollution.

Air pollution is a major worldwide health issue in urban areas, with 91% of the world’s city-dwelling population exposed to particulate matter in concentrations that exceed the World Health Organization’s air quality guidelines. Closer to home, the WHO database for 2018 revealed than 49 UK towns and cities are failing standards for fine particle air pollution. This is not just in the massive conurbations that we might expect to have a problem: the list includes Eastbourne, Chepstow and Eccles. A data audit in February by Friends of the Earth revealed that an astonishing 1,758 sites across England, Wales and Northern Ireland breached the annual air quality objective for nitrogen dioxide. Here in London, figures published in April revealed that 2 million people are living with dangerously high levels of pollution. This figure includes 400,000 children, with 400 schools in areas with over-the-limit levels of nitrogen dioxide.

We know that the most significant cause of poor-quality air in urban areas is pollutants released in combustion. To date, research has focused largely on the physical impact of early exposure to poor-quality air, but two recent studies from King’s College London —of which I declare my interest as an employee—demonstrate for the first time its impact on mental health. Both studies took advantage of two data sources: detailed geographical air pollution data, collected at sites across London, and the well-established E-risk longitudinal twin study. This nationally representative sample of twins born between 1994 and 1995 includes 2,232 children, who were assessed first at age five and then regularly up to age 18. In the studies, residential addresses as well two additional addresses at which they spent their time—that is, their schools—were linked with air quality data to estimate the children’s exposure to pollutants across the year. The findings are frightening.

The first paper revealed that exposure to air pollution at age 12 had a significant association with depression at age 18, with children living in the top 25% of the most polluted areas three to four times more susceptible than those living in the top 25% of the least polluted areas. The most likely cause, the researchers say, was pollutant particles small enough to cross the blood-brain barrier, causing inflammation in the brain, which is known to link to the development of depressive symptoms.

The second study provided what is believed to be the first evidence of a link between air pollution and psychotic experiences in adolescence. The connection between growing up in a city and an increased risk of psychosis has long been accepted, but most of the efforts to understand the link have concentrated on social factors such as neighbourhood deprivation or crime. In focusing on air pollution—a key element of the urban environment—researchers found that psychotic experiences were significantly more common among young people with the highest annual exposure to nitrogen dioxide, nitrogen oxide and fine particle air pollution. These pollutants are all subject to legally binding limits—limits that we know are not being met in towns and cities across the UK. The findings indicate that even if they were being met, young people’s longer-term mental health would still be at risk. Even at exposure levels lower than international guidelines recommend, nitrogen dioxide was found to be significantly associated with adolescent psychotic experiences.

Researchers from King’s College London believe that if the recent trend of inaction continues, it will take 193 years to reach legal compliance on air quality. We cannot allow that to be the case. The Government’s clean air strategy commits to progressively cut public exposure to particulate matter so that the number of people living in locations above the WHO guideline level is reduced by 50% by 2025. Does the Minister agree that, given the public health crisis we are hearing about today, this rate of progress is just not ambitious enough? It is estimated that, by 2050, 70% of the world’s population will live in cities. Unless we take urgent action now to tackle emissions and improve air quality in the urban environment, generations of children into the future will be breathing air that will damage them for life.