H5N1

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.

Air pollution may be ‘key contributor’ to COVID-19 deaths – study

Via The Guardian: Air pollution may be ‘key contributor’ to Covid-19 deaths – study. Excerpt:

High levels of air pollution may be “one of the most important contributors” to deaths from Covid-19, according to research. 

The analysis shows that of the coronavirus deaths across 66 administrative regions in Italy, Spain, France and Germany, 78% of them occurred in just five regions, and these were the most polluted. 

The research examined levels of nitrogen dioxide, a pollutant produced mostly by diesel vehicles, and weather conditions that can prevent dirty air from dispersing away from a city. Many studies have linked NO2 exposure to health damage, and particularly lung disease, which could make people more likely to die if they contract Covid-19. 

“The results indicate that long-term exposure to this pollutant may be one of the most important contributors to fatality caused by the Covid-19 virus in these regions and maybe across the whole world,” said Yaron Ogen, at Martin Luther University Halle-Wittenberg in Germany, who conducted the research. “Poisoning our environment means poisoning our own body, and when it experiences chronic respiratory stress its ability to defend itself from infections is limited.”  

The analysis is only able to show a strong correlation, not a causal link. “It is now necessary to examine whether the presence of an initial inflammatory condition is related to the response of the immune system to the coronavirus,” Ogen said. 

A separate study published on 7 April looked at fine particle pollution in the US and found that even small increases in levels in the years before the pandemic were associated with far higher Covid-19 death rates. Another recent paper noted that the high death rates seen in the north of Italy correlated with the highest levels of air pollution. 

The new research, published in the journal Science of the Total Environment, compared NO2 levels in January and February in 66 administrative regions with Covid-19 deaths recorded up to 19 March. Ogen also assessed the atmospheric conditions to see where pollution was being trapped over the regions. 

He found that 78% of the 4,443 deaths were in four regions in northern Italy and one around Madrid in Spain. These five regions had the worst combination of NO2 levels and airflow conditions that prevented dispersal of air pollution.

Wildfire smoke worsens COVID-19 risk, putting firefighters in extra danger

Via The Conversation, an article by Professor Luke Montrose of Boise State University: Wildfire smoke worsens coronavirus risk, putting firefighters in extra danger. Excerpt:

As summer approaches, two forces of nature are on a collision course, and wildland firefighters will be caught in the middle.  

New research suggests that the smoke firefighters breathe on the front lines of wildfires is putting them at greater risk from the new coronavirus, with potentially lethal effects. 

At the same time, firefighting conditions make precautions such as social distancing and hand-washing difficult, increasing the chance that, once the virus enters a fire camp, it could quickly spread.  

As an environmental toxicologist, I have spent the last decade expanding our understanding of how wood smoke exposure impacts human health. Much of my current research is focused on protecting the long-term health of wildland firefighters and the communities they serve. 

‘Camp crud’ and the dangers of air pollution 

People have long understood that the air they breathe can impact their health, dating back more than 2,000 years to Hippocrates in his treatise on Air, Water, and Places. Today, there is a growing consensus among researchers that air pollution, specifically the very fine particles called PM2.5, influences risk of respiratory illness. These particles are a tiny fraction of the width of a hair and can travel deep into the lungs. 

Italian scientists reported in 2014 that air pollutants can increase the viral load in the lungs and reduce the ability of specialized cells called macrophages to clear out viral invaders. 

Researchers in Montana later connected that effect to wood smoke. They found that animals exposed to wood smoke 24 hours before being exposed to a pathogen ended up with more pathogen in their lungs. The researchers showed that wood smoke exposure decreased the macrophages’ ability to combat respiratory infection. 

Now, new evidence suggests that long-term exposure to PM2.5 air pollution, which is produced by sources such as wildfires, power plants and vehicles, may make coronavirus particularly deadly. 

Researchers from the Harvard T.H. Chan School of Public Health conducted a nationwide study of county-level data and found that even a small increase in the amount of PM2.5 from one U.S. county to the next was associated with a large increase in the death rate from COVID-19. While small increases in PM2.5 also raise the risk of death from other causes for older adults, the magnitude of the increase for COVID-19 was about 20 times greater. The results were released last week, before the usual peer review process was conducted, to help warn people of the risks.

Taken together, these findings suggest that air pollution, including wood smoke, could increase the risk that wildland firefighters will develop severe COVID-19 symptoms.

'It's positively alpine!': Disbelief in big cities as air pollution falls

Via The Guardian, some good news: 'It's positively alpine!': Disbelief in big cities as air pollution falls. The before-and-after photos are, un, breathtaking. Excerpt and then a comment:

The screenshots began to circulate on Delhi WhatsApp groups last week, captioned with varying expressions of disbelief. Having checked the air quality index, something of a sadistic morning ritual among residents of India’s capital, most could not believe their eyes. 

Gone was the familiar menacing red banner, indicating how each intake of breath is really just a toxic blast on the lungs, replaced instead by a healthy, cheerful green. Could it really be that Delhi’s pollution levels now fell into the category of … “good”? “It’s positively alpine!” exclaimed one message.  

A nationwide lockdown imposed across India almost two weeks ago to stop the spread of the coronavirus – the largest lockdown of its kind attempted anywhere – has led to widespread chaos and suffering, especially among the country’s 300 million poor. Yet in Delhi, the world’s most polluted city, it has also resulted in some of the freshest air the capital has seen in decades. 

It is a lockdown silver lining being repeated across the world, as toxic megacities such as Bangkok, Beijing, São Paulo and Bogotá, where varying coronavirus restrictions have been imposed, all reported an unprecedented decline in pollution. Yet it is countered with one cruel irony: with most residents of these cities strictly confined to their homes, few have any way to appreciate this newly fresh air, except through an open window or a during speedy trip to the supermarket. 

In Delhi, air quality index (AQI) levels are usually a severe 200 on a good day (anything above 25 is deemed unsafe by World Health Organization). During peak pollution periods last year they soared well into a life-threatening 900 and sometimes off the measurable scale. But as Delhi’s 11m registered cars were taken off the roads and factories and construction were ground to a halt, AQI levels have regularly fallen below 20. The skies are suddenly a rare, piercing blue. Even the birdsong seems louder.  

Dr Shashi Tharoor, a politician and author who has been vocal on environmental issues, said he hoped that it was a wake-up call. “The blissful sight of blue skies and the joy of breathing clean air provides just the contrast to illustrate what we are doing to ourselves the rest of the time,” said Tharoor. “Today the typical Delhi AQI hovers around 30 and one blissful afternoon, after a spurt of rain, it dropped to 7.” 

“Seven,” Tharoor exclaimed again in disbelief. “In Delhi! Pure joy!”.

But curb your enthusiasm: As of 8:00 p.m. Saturday, local time, Current Delhi AQI is the moderate to unhealthy range.