H5N1

Syndemic responses to COVID-19 should include an ecological dimension

Correspondence in The Lancet: Syndemic responses to COVID-19 should include an ecological dimension

Richard Horton argued persuasively that COVID-19 should be addressed as a syndemic of biological and social interactions. When planning the “national revival” he calls for, I consider it crucial that this syndemic approach includes an ecological dimension. Studies have found that widespread anthropogenic ecosystem degradation has played a crucial role in explaining why the rate of emergence of zoonoses has been increasing over the past 40 years. 

For example, deforestation, intensified agriculture and livestock production, and climate change have been linked to the emergence of Ebola virus, HIV, Nipah virus, severe acute respiratory syndrome coronavirus, and Zika virus. Unless reversed, the anthropogenic destruction of habitats will probably lead to the continued emergence of new zoonoses from the estimated 700 000 other unidentified viruses with zoonotic potential. 

As argued in the recent Living Planet Report, COVID-19 is “nature sending us a message”: we need to cut human consumption to within the planet's “safe operating space”. For the vital reasons Horton outlines, this needs to be done in a way which promotes, rather than exacerbates, national and international socioeconomic equity. National revival plans could play an important role in this process but should be subordinate to international plans that are based on determinations of both global equity and ecological constraints.

Regional and global contributions of air pollution to risk of death from COVID-19

Via Cardiovascular Research: Regional and global contributions of air pollution to risk of death from COVID-19. The abstract:

Aims 

The risk of mortality from the coronavirus disease that emerged in 2019 (COVID-19) is increased by comorbidity from cardiovascular and pulmonary diseases. Air pollution also causes excess mortality from these conditions. Analysis of the first severe acute respiratory syndrome coronavirus (SARS-CoV-1) outcomes in 2003, and preliminary investigations of those for SARS-CoV-2 since 2019, provide evidence that the incidence and severity are related to ambient air pollution. We estimated the fraction of COVID-19 mortality that is attributable to the long-term exposure to ambient fine particulate air pollution. 

Methods and results 

We characterized global exposure to fine particulates based on satellite data, and calculated the anthropogenic fraction with an atmospheric chemistry model. The degree to which air pollution influences COVID-19 mortality was derived from epidemiological data in the USA and China. We estimate that particulate air pollution contributed ∼15% (95% confidence interval 7–33%) to COVID-19 mortality worldwide, 27% (13 – 46%) in East Asia, 19% (8–41%) in Europe, and 17% (6–39%) in North America. Globally, ∼50–60% of the attributable, anthropogenic fraction is related to fossil fuel use, up to 70–80% in Europe, West Asia, and North America.  

Conclusion 

Our results suggest that air pollution is an important cofactor increasing the risk of mortality from COVID-19. This provides extra motivation for combining ambitious policies to reduce air pollution with measures to control the transmission of COVID-19.

Richard Horton: Reasons for hope

In The Lancet, its editor Richard Horton writes: Offline: Reasons for hope.

Fatigue. Despair. Misery. Cracks are beginning to appear in our mental resilience. 10 months of this calamity. How much more can we bear? It was always so. When the Bishop of Winchester died of plague in 1626, John Milton issued a searing cry of anguish in his Elegia Tertia. The great poet was just 17 years old, “sad...with no companion, and many sorrows clung to my soul”. He sought to commemorate this “grim killing” of a revered literary figure, a “dreadful death, fearsome with her sepulchral torch”. “Why does it please you”, Milton asked, “to stain your hands with human slaughter, and to have sharpened sure arrows against a noble breast, and to have driven a half-divine soul from its home?” 

It would be easy to sink into despondency. Governments are struggling. The public is restless. We need hope. There was one buoyant piece of news last week. The UK's National Health Service (NHS) committed itself to becoming the world's first carbon net zero health system by 2040. WHO's Director-General, Tedros Adhanom Ghebreyesus, welcomed the news, noting that “Health is leading the way to a greener, safer planet.” The NHS has appointed Nick Watts, who has blazingly led The Lancet's Countdown on Health and Climate Change, as its first Chief Sustainability Officer. This news is certainly one reason for hope.

As Laura Spinney pointed out in her history of the 1918 influenza pandemic, Pale Rider (2017), humanity was left transformed once the infection ebbed. Out of tragedy came regeneration. “The 1918 pandemic accelerated the pace of change in the first half of the twentieth century, and helped shape our modern world.” Societies bounced back. The 1920s ushered in a new era of intellectual and artistic creativity. Governments embraced health and made it an explicit political priority—“The state of a nation's health came to be seen as an index of its modernity or civilisation.” The conditions for universal health care were created. There was a “psychological shift” across the world. Although we are still in the midst of a dreadful coronavirus syndemic, if we lift our gaze we can see a better future ahead, a future that is up to us to define. Our societies can revive, stronger, smarter, and kinder. The first step is to reinvigorate our conversation about what tomorrow should look like. That conversation has started.  

Fran Baum and Sharon Friel recently proposed the need for a social as well as a biological vaccine to solve the challenge of COVID-19. They argued in the Medical Journal of Australia that we need to go beyond a biomedical vision for solving this syndemic. By a social vaccine, they mean “a metaphor designed to shift the dominant biomedical orientation of the health sector towards the underlying distal factors that cause disease and suffering”. 

They set our four foundational requirements for health—a life with security, opportunities that are fair, a planet that is habitable and supports biodiversity, and governance that is just. Each of these requirements determines the components of a social vaccine. A life with security demands a universal system to guarantee social protection, employment, and shelter; progressive taxation; and international treaties to ensure peace and security. 

Opportunities that are fair include (at a minimum) universal and free education; racial, sex, and disability discrimination laws; decent jobs; and environments that enable healthy choices. A planet that is habitable requires a zero carbon future; protection of biodiversity; and elimination of fossil fuel subsidies. Finally, governance that is just means a universal franchise; robust systems of political accountability; and strong civil society organisations, protected by legislation. 

They write, inspiringly, that, “A global social vaccine will enable a new way of living that is healthy, just, convivial, and sustainable, and will inoculate future society against a return to a world growing increasingly less healthy, sustainable, and equal.” 

Or turn to Rene Loewenson and colleagues who wrote a powerful call to reclaim a comprehensive public health in BMJ Global Health last month—“Biosecurity is not equal to public health”, they insisted. 

Something is stirring in the heart of our society. In health, the debate about our future is intensifying. Old assumptions are being questioned. New directions are being proposed. Amid the carnage of COVID-19, a renaissance of hope is emerging. It's time to join the conversation about the world to come.

My own thoughts on the world to come are here.

Doctors alarmed by surge in hospital visits as toxic smoke engulfs west coast

Via The Guardian: Doctors alarmed by surge in hospital visits as toxic smoke engulfs west coast. Excerpt:

A month after hundreds of wildfires started spewing toxic smoke along the entire west coast, doctors are seeing the alarming health effects of air pollution piling up.  

In northern California’s Stanford Health Care system, hospital admissions have jumped by 12% in recent weeks, including a stunning 43% jump in cerebrovascular conditions such as strokes. In Oregon, health officials reported nearly one out of 10 people visiting the emergency room had asthma-like conditions due to the smoke. And in San Francisco, doctors had to cancel their clinics for recovering Covid-19 patients, because the air was so unhealthy that just getting to their appointments could make patients more sick.  

A growing body of scientific evidence paints a dire picture of the effects of wildfire smoke on the human body. Experts told the Guardian earlier this month that the smoke can have an almost immediate effect on people’s health, causing asthma, heart attacks, kidney problems and even mental health issues to surge.

Now, as the west coast reckons with an unprecedented stretch of hazardous air, scientists and health experts are growing even more concerned about the immediate and long-term consequences of continuous exposure to the harmful pollution. 

In the Bay Area, despite firefighters gaining control of the nearest blazes started by lightning strikes in August, smoky conditions have persisted, turning the sky orange and keeping people inside their homes. 

“We’re on the 30th consecutive day of our ‘Spare the Air’ alerts,” said Kristina Chu of the Bay Area air quality management district on Wednesday. “That’s an all-time record,” she explained; the previous longest was 14 days.

AQI on Monday morning: Vancouver 228 (very unhealthy); Portland 468 (hazardous)

I just checked the AQI for Vancouver Second Narrows, which is not far from where I live, and it's the worst I've ever seen it:

Then I checked Portland Postal Bldg., Oregon, USA Air Pollution: Real-time Air Quality Index, and it's far worse than ours:

The public health consequences for the whole west coast, Canada and the US alike, are going to be serious.

 

Smoke in Vancouver

A screenshot from North Vancouver Second Narrows, British Columbia Air Pollution: Real-time Air Quality Index:

The smoke is very visible, though it's not as bad as the summer of 2017, when the sun was orange in a grey sky. Presumably it's coming up from California as well as the wildfires in the BC Interior. 

The effect of air pollution on deaths, disease burden, and life expectancy across China and its provinces, 1990–2017

Via The Lancet Planetary Health: The effect of air pollution on deaths, disease burden, and life expectancy across China and its provinces, 1990–2017: an analysis for the Global Burden of Disease Study 2017. The summary:

Background 

Air pollution is an important public health concern in China, with high levels of exposure to both ambient and household air pollution. To inform action at provincial levels in China, we estimated the exposure to air pollution and its effect on deaths, disease burden, and loss of life expectancy across all provinces in China from 1990 to 2017. 

Methods 

In all 33 provinces, autonomous regions, municipalities, and special administrative regions in China, we estimated exposure to air pollution, including ambient particulate matter pollution (defined as the annual gridded concentration of PM2·5), household air pollution (defined as the percentage of households using solid cooking fuels and the corresponding exposure to PM2·5), and ozone pollution (defined as average gridded ozone concentrations). 

We used the methods of the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 to estimate deaths and disability-adjusted life-years (DALYs) attributable to air pollution, and what the life expectancy would have been if air pollution levels had been less than the minimum level causing health loss. 

Findings 

The average annual population-weighted PM2·5 exposure in China was 52·7 μg/m3 (95% uncertainty interval [UI] 41·0–62·8) in 2017, which is 9% lower than in 1990 (57·8 μg/m3, 45·0–67·0). We estimated that 1·24 million (95% UI 1·08–1·40) deaths in China were attributable to air pollution in 2017, including 851 660 (712 002–990 271) from ambient PM2·5 pollution, 271 089 (209 882–346 561) from household air pollution from solid fuels, and 178 187 (67 650–286 229) from ambient ozone pollution. 

The age-standardised DALY rate attributable to air pollution was 1513·1 per 100 000 in China in 2017, and was higher in males (1839·8 per 100 000) than in females (1198·3 per 100 000). The age-standardised death rate attributable to air pollution decreased by 60·6% (55·7–63·7) for China overall between 1990 and 2017, driven by an 85·4% (83·2–87·3) decline in household air pollution and a 12·0% (1·4–22·1) decline in ambient PM2·5 pollution. 

40·0% of DALYs for COPD were attributable to air pollution, as were 35·6% of DALYs for lower respiratory infections, 26·1% for diabetes, 25·8% for lung cancer, 19·5% for ischaemic heart disease, and 12·8% for stroke. We estimated that if the air pollution level in China was below the minimum causing health loss, the average life expectancy would have been 1·25 years greater. 

The DALY rate per 100 000 attributable to air pollution varied across provinces, ranging from 482·3 (371·1–604·1) in Hong Kong to 1725·6 (720·4–2653·1) in Xinjiang for ambient pollution, and from 18·7 (9·1–34·0) in Shanghai to 1804·5 (1339·5–2270·1) in Tibet for household pollution. Although the overall mortality attributable to air pollution decreased in China between 1990 and 2017, 12 provinces showed an increasing trend during the past 27 years. 

Interpretation 

Pollution from ambient PM2·5 and household burning of solid fuels decreased markedly in recent years in China, after extensive efforts to control emissions. However, PM2·5 concentrations still exceed the WHO Air Quality Guideline for the entire population of China, with 81% living in regions exceeding the WHO Interim Target 1, and air pollution remains an important risk factor. Sustainable development policies should be implemented and enforced to reduce the impact of air pollution on long-term economic development and population health.

A vulnerability index for the management of and response to the COVID-19 epidemic in India: An ecological study

Via The Lancet Global Health: A vulnerability index for the management of and response to the COVID-19 epidemic in India: an ecological study. The summary:

Background 

COVID-19 is spreading rapidly in India and other parts of the world. Despite the Indian Government's efforts to contain the disease in the affected districts, cases have been reported in 627 (98%) of 640 districts. There is a need to devise a tool for district-level planning and prioritisation and effective allocation of resources. Based on publicly available data, this study reports a vulnerability index for identification of vulnerable regions in India on the basis of population and infrastructural characteristics. 

Methods 

We computed a composite index of vulnerability at the state and district levels based on 15 indicators across the following five domains: socioeconomic, demographic, housing and hygiene, epidemiological, and health system. We used a percentile ranking method to compute both domain-specific and overall vulnerability and presented results spatially with number of positive COVID-19 cases in districts. 

Findings 

A number of districts in nine large states—Bihar, Madhya Pradesh, Telangana, Jharkhand, Uttar Pradesh, Maharashtra, West Bengal, Odisha, and Gujarat—located in every region of the country except the northeast, were found to have high overall vulnerability (index value more than 0·75). These states also had high vulnerability according to most of the five domains. Although our intention was not to predict the risk of infection for a district or a state, we observed similarities between vulnerability and the current concentration of COVID-19 cases at the state level. However, this relationship was not clear at the district level. 

Interpretation 

The vulnerability index presented in this paper identified a number of vulnerable districts in India, which currently do not have large numbers of COVID-19 cases but could be strongly impacted by the epidemic. Our index aims to help planners and policy makers effectively prioritise regions for resource allocation and adopt risk mitigation strategies for better preparedness and responses to the COVID-19 epidemic.

The changing risk and burden of wildfire in the US

Via the National Bureau of Economics: The Changing Risk and Burden of Wildfire in the US. The abstract:

Recent dramatic and deadly increases in global wildfire activity have increased attention on the causes of wildfires, their consequences, and how risk from fire might be mitigated. Here we bring together data on the changing risk and societal burden of wildfire in the US. 

We estimate that nearly 50 million homes are currently in the wildland-urban interface in the US, a number increasing by 1 million houses every 3 years. Using a statistical model that links satellite-based fire and smoke data to pollution monitoring stations, we estimate that wildfires have accounted for up to 25% of PM2.5 in recent years across the US, and up to half in some Western regions. 

We then show that ambient exposure to smoke-based PM2.5 does not follow traditional socioeconomic exposure gradients. Finally, using stylized scenarios, we show that fuels management interventions have large but uncertain impacts on health outcomes, and that future health impacts from climate-change-induced wildfire smoke could approach projected overall increases in temperature-related mortality from climate change. We draw lessons for research and policy.

Air pollution reduction and mortality benefit during the COVID-19 outbreak in China

Via The Lancet Planetary Health: Air pollution reduction and mortality benefit during the COVID-19 outbreak in China. The conclusion, with my bolding:

We found that, because of the quarantine, NO2 dropped by 22·8 μg/m3 in Wuhan and 12·9 μg/m3 in China. PM2·5 dropped by 1·4 μg/m3 in Wuhan but decreased by 18·9 μg/m3 across 367 cities (appendix p 3). The smaller reduction in PM2·5 in Wuhan is due to a similar decreasing trend in PM2·5 in 2016–2019. The pronounced decline in NO2 across China during the quarantine period was also detected by the Copernicus Sentinel-5P satellite with the NO2 tropospheric column density (figure). 

We estimate that improved air quality during the quarantine period avoided a total of 8911 NO2-related deaths (95% CI 6950–10 866), 65% of which were from cardiovascular diseases (hypertensive disease, coronary heart disease, and stroke) and COPD (figure, appendix p 4). Furthermore, we estimate that reduction in PM2·5 during the quarantine period avoided a total of 3214 PM2·5-related deaths (95% CI 2340–4087) in China, 73% of which were from cardiovascular diseases and COPD. Similar estimates were found with an alternative before quarantine period from Jan 1 to Jan 20 (appendix p 3–4). 

Our estimates should be interpreted with caution because of the potential overlap between PM2·5 and NO2-related mortality and the effect on mortality rate from disrupted health-care systems during the quarantine, which could have impacted the timely treatment of patients with chronic diseases. We used cause-specific CRFs from single-pollutant models because coefficients from two-pollutant models were not available. Although there might have been some risk of double counting, results from published literature suggest that this risk is small because effect estimates for NO2 and PM2·5 were similar between single-pollutant and two-pollutant models. Moreover, similar to previous epidemiological studies with outdoor air pollution, exposure measurement error is inevitable since most people stayed indoors. 

Our estimates suggest that interventions to contain the COVID-19 outbreak led to improvements in air quality that brought health benefits in non-COVID-19 deaths, which could potentially have outnumbered the confirmed deaths attributable to COVID-19 in China (4633 deaths as of May 4, 2020). Our findings show the substantial human health benefits related to cardiovascular disease morbidity and mortality that can be achieved when aggressive control measures for air pollution are taken to reduce emissions from vehicles, such as through climate mitigation-related traffic restrictions or efforts to accelerate the transition to electric vehicles.