An editorial in The Lancet Respiratory Medicine: Breathing on a hot planet. Excerpt:
The summer of 2018 saw devastating heat in the northern hemisphere. The UK experienced a prolonged heatwave and drought, with water reservoirs running low by mid-July; the Japanese Government declared a natural disaster as temperatures soared to over 40°C; fires tore through California and Europe, and blazes were reported as far north as the Arctic Circle. All-time high temperatures were recorded in Africa (Ouargla, Algeria, 51·3°C) and Japan (Kumagaya, 41·1°C), as well as in hundreds of other towns and cities across the world.
If any more proof were needed that the global climate is rapidly changing, the summer of 2018 provided it. A preliminary analysis by the World Weather Attribution Consortium concluded that the extreme heat events had been made almost twice as likely by human-induced climate change. Clearly, efforts to mitigate climate change—which have so far been slow, piecemeal, and hampered by climate denial—have not achieved enough. As time goes on, summers like this will become less and less exceptional, and we must focus on adaptation as well as mitigation to protect public health.
Extremes of heat are particularly hazardous to those with respiratory disease. Exacerbations of chronic conditions such as chronic obstructive pulmonary disease (COPD) and asthma increase drastically in line with high temperatures, often aggravated by increased air pollution in cities, as well as seasonal allergies. Furthermore, smoke inhalation from wildfires can have both acute and long-term respiratory consequences.
So what changes are needed to protect lung health in this warming world? A first step might involve improving diagnosis and treatment of mild-to-moderate asthma and COPD. Findings from several epidemiological studies suggest that around 75% of COPD cases remain undiagnosed.
Furthermore, the epidemic thunderstorm asthma event of 2016 in Melbourne, Australia, in which high pollen counts and an unusual weather front caused mass respiratory problems, pointed to widespread underdiagnosis of asthma, with only 43% of people who presented to emergency departments with thunderstorm asthma having a previous asthma diagnosis. Simply being aware of their condition, as well as having access to reliever medications, would make patients with mild-to-moderate asthma and COPD far more resilient when it comes to exacerbations caused by heatwaves, and more able to self-manage.
Increasing health system resilience is also a key element of adaptation. In late July, 2018, the UK National Health Service (NHS) looked to be on the verge of a “summer crisis”, with some trusts reporting record numbers of accident and emergency admissions, mostly for respiratory exacerbations. A new report on heatwaves by the UK House of Commons Environmental Audit Committee noted that frontline NHS staff felt unprepared for heatwaves, and less than half of general practitioners surveyed were confident about resilience to extreme events.
As well as action plans and staff training, a large part of resilience is ensuring that emergency resources—including money, medicines, and hospital beds—are available when extreme events happen. Governments must begin to set aside emergency funds to support health systems during heatwaves.
Urgent, year-round action on air pollution is also required. High levels of particulate matter (PM) and ozone are major drivers of heat-related respiratory exacerbations. Residents of large cities are most affected by heatwaves because of the urban heat sink effect, a lack of green space, and worse air quality; for example, the 2003 European heatwave saw excess mortality increase by 17% across England and Wales as a whole, but by 40% in London.
In recent years, there has been a surge in public awareness of air pollution in major cities, yet change remains slow. In June, 2018, official air pollution monitors in Delhi, India, recorded “off the charts” PM10 concentrations of 999 μg/m3—the highest possible measurement. Just a few months earlier, the UK Government's plan to tackle urban air pollution was declared by the High Court to be so inadequate it was unlawful.