About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

10/27/20


https://www.news-medical.net/news/20201 ... ution.aspx


Long-term exposure to air pollution has been linked to an increased risk of dying from COVID-19 and, for the first time, a study has estimated the proportion of deaths from the coronavirus that could be attributed to the exacerbating effects of air pollution for every country in the world.

The study, published in Cardiovascular Researchtoday (Tuesday), estimated that about 15% of deaths worldwide from COVID-19 could be attributed to long-term exposure to air pollution. In Europe the proportion was about 19%, in North America it was 17%, and in East Asia about 27%.

In their CVR paper, the researchers write that these proportions are an estimate of "the fraction of COVID-19 deaths that could be avoided if the population were exposed to lower counterfactual air pollution levels without fossil fuel-related and other anthropogenic [caused by humans] emissions".

They add that this "attributable fraction does not imply a direct cause-effect relationship between air pollution and COVID-19 mortality (although it is possible). Instead it refers to relationships between two, direct and indirect, i.e. by aggravating co-morbidities [other health conditions] that could lead to fatal health outcomes of the virus infection".

The research team includes Professor Jos Lelieveld, of the Max Planck Institute for Chemistry, Mainz, Germany, and the Cyprus Institute Nicosia, Cyprus, Professor Thomas Münzel, from the University Medical Center of the Johannes Gutenberg University, Mainz, and the German Center for Cardiovascular Research, Mainz, and Dr. Andrea Pozzer, from the Max Planck Institute for Chemistry.

The researchers used epidemiological data from previous US and Chinese studies of air pollution and COVID-19 and the SARS outbreak in 2003, supported by additional data from Italy.

They combined this with satellite data showing global exposure to polluting fine particles known as 'particulate matter' that are less than or equal to 2.5 microns in diameter (known as PM2.5), information on atmospheric conditions and ground-based pollution monitoring networks, to create a model to calculate the fraction of coronavirus deaths that could be attributable to long-term exposure to PM2.5.

The results are based on epidemiological data collected up the third week in June 2020 and the researchers say a comprehensive evaluation will need to follow after the pandemic has subsided.

Estimates for individual countries show, for example, that air pollution contributed to 29% of coronavirus deaths in the Czech Republic, 27% in China, 26% in Germany, 22% in Switzerland, 21% in Belgium, 19% in The Netherlands, 18% in France, 16% in Sweden, 15% in Italy, 14% in the UK, 12% in Brazil, 11% in Portugal, 8% in the Republic of Ireland, 6% in Israel, 3% in Australia and just 1% in New Zealand.

Professor Jos Lelieveld said:

Since the numbers of deaths from COVID-19 are increasing all the time, it's not possible to give exact or final numbers of COVID-19 deaths per country that can be attributed to air pollution.

However, as an example, in the UK there have been over 44,000 coronavirus deaths and we estimate that the fraction attributable to air pollution is 14%, meaning that more than 6,100 deaths could be attributed to air pollution.

In the USA, more than 220,000 COVID deaths with a fraction of 18% yields about 40,000 deaths attributable to air pollution."

Prof. Münzel said: "When people inhale polluted air, the very small polluting particles, the PM2.5, migrate from the lungs to the blood and blood vessels, causing inflammation and severe oxidative stress, which is an imbalance between free radicals and oxidants in the body that normally repair damage to cells. This causes damage to the inner lining of arteries, the endothelium, and leads to the narrowing and stiffening of the arteries. The COVID-19 virus also enters the body via the lungs, causing similar damage to blood vessels, and it is now considered to be an endothelial disease.

"If both long-term exposure to air pollution and infection with the COVID-19 virus come together then we have an additive adverse effect on health, particularly with respect to the heart and blood vessels, which leads to greater vulnerability and less resilience to COVID-19. If you already have heart disease, then air pollution and coronavirus infection will cause trouble that can lead to heart attacks, heart failure and stroke."

Referring to previous work that suggests that the fine particulates in air pollution may prolong the atmospheric lifetime of infectious viruses and help them to infect more people [1], Prof. Lelieveld said: "It's likely that particulate matter plays a role in 'super-spreading events' by favouring transmission."

Prof. Münzel added: "Particulate matter seems to increase the activity of a receptor on cell surfaces, called ACE-2, that is known to be involved in the way COVID-19 infects cells. So we have a 'double hit': air pollution damages the lungs and increases the activity of ACE-2, which in turn leads to enhanced uptake of the virus by the lungs and probably by the blood vessels and the heart."

In their paper, the authors conclude: "Our results suggest the potential for substantial benefits from reducing air pollution exposure, even at relatively low PM2.5 levels. . . . A lesson from our environmental perspective of the COVID-19 pandemic is that the quest for effective policies to reduce anthropogenic emissions, which cause both air pollution and climate change, needs to be accelerated. The pandemic ends with the vaccination of the population or with herd immunity through extensive infection of the population.

"However, there are no vaccines against poor air quality and climate change. The remedy is to mitigate emissions. The transition to a green economy with clean, renewable energy sources will further both environmental and public health locally through improved air quality and globally by limiting climate change."

The study is also the first of its kind to distinguish between fossil fuel-related and other human-made sources of air pollution.

One limitation of the research is that epidemiological data from the US were collected at the level of counties rather than from individuals, which means that it is more difficult to exclude confounding factors. Even though 20 factors that could affect the results were accounted for, additional factors cannot be excluded.

A second limitation is that data have been collected in middle- to high-income countries (China, US, and corroborated by data from Europe); the calculations were carried out for the whole world, meaning that the results for low-income countries may be less robust.

Source:

European Society of Cardiology
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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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Exposure to environmental immunotoxicants may worsen outcome of SARS-CoV-2 infection

11/02/20


https://www.news-medical.net/news/20201 ... ction.aspx


Several studies have shown that increased exposure to polluted air is associated with the severity of disease. Air pollution has also been shown to aggravate the course of the coronavirus disease 2019 (COVID-19) pandemic. Many industrial chemicals are known to suppress immune functions and worsen the disease course in many infections. Globally disseminated and immunotoxic industrial chemicals like perfluorinated alkylate substances (PFAS) may contribute to this as well.

Thus, elevated background exposure to PFAS is associated with decreased antibody responses to vaccinations in children and adults. Also, children with higher levels of exposure to these chemicals are more prone to infectious diseases. Moreover, major PFAS are said to interfere with proteins involved in critical pathways linked to severe clinical outcomes for COVID-19.
Assessing the impact of elevated PFAS exposures on the course of SARS-CoV-2 infection

A team of researchers from the Harvard T.H.Chan School of Public Health, Boston, MA; University of Southern Denmark; Odense University Hospital, Denmark; Statens Serum Institut, Copenhagen, Denmark; National University Hospital, Copenhagen, Denmark; and the University of Copenhagen recently carried out a study in Denmark in which they determined the plasma PFAS concentrations in individuals with a confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection.

They wanted to assess the impact of elevated background exposures to immunotoxic PFAS on the infection's clinical course and study the association of PFAS exposure with the COVID-19 severity. Their work is published on the preprint server medRxiv*.

Using ordinal and ordered logistic regression analyses to identify links between PFAS levels and disease severity.

The team obtained plasma samples of 323 individuals with confirmed SARS-CoV-2 infection from Danish biobanks. The subjects belonged to the age group of 30-70 years. The concentrations of PFAS were measured at the background exposures, and the study included 5 PFAS that are known to be immunotoxic.

Registration data of the subjects was obtained to classify them based on disease status and demographic variables. The team used ordinal and ordered logistic regression analyses to study the associations between PFAS levels and clinical outcomes.

The study results showed that plasma-PFAS levels were higher in males and patients with Western European background. While the PFAS levels tend to increase with age, they were not necessarily associated with the presence of chronic disease. Out of 323 subjects, 108 (33%) were not hospitalized, and among those who were hospitalized, 53 (16%) were either in intensive care or deceased.

"The results of this study are parallel to findings in regard to other environmental toxicants, viz., air pollutants and suggests a need to ascertain the impact of relevant occupational or environmental exposures on COVID-19 severity."

Among the five immunotoxic PFAS studied, perfluorobutanoic acid (PFBA) had an odds ratio (OR) of 2.19 for increasing disease severity. However, OR decreased to 1.77 after it was adjusted for sex, age, sampling site, blood sampling, and diagnosis interval.

Increased plasma concentrations of PFBA is associated with severe COVID-19 prognosis

This study aimed at evaluating the potential worsening of COVID-19 disease associated with increased background exposure to PFAS. Several PFAS have been shown to be immunotoxic agents in experiments with lab animals and also in humans.

According to the authors, this study's results agree with the findings of previous studies on other environmental toxicants or air pollutants and highlights the need to confirm the impact of occupational or environmental exposures to air pollutants on the severity of COVID-19.

The team says that while existing evidence on air pollution is solely based on ecological studies that don't take into account individual exposure levels, their present study benefits from determining the plasma-PFAS levels of the subjects.

The authors concluded that increased plasma PFBA levels were associated with more severe COVID-19 prognosis, even after adjustment for comorbidities, sex, age, origin, sampling time, and location. Although PFBA levels in plasma were lower than most PFAS studied, PBFA accumulates in the lungs, and hence they believe that PBFA exposure may contribute to the severity of disease.

"These findings at background exposure levels suggest a need to ascertain if exposures to environmental immunotoxicants may worsen the outcome of the SARS-CoV-2 infection."

*Important Notice

medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Journal reference:


Severity of COVID-19 at elevated exposure to perfluorinated alkylates Philippe Grandjean, Clara Amalie Gade Timmermann, Marie Kruse, Flemming Nielsen, Pernille Just Vinholt, Lasse Boding, Carsten Heilmann, Kaare Molbak medRxiv 2020.10.22.20217562; doi: https://doi.org/10.1101/2020.10.22.20217562, https://www.medrxiv.org/content/10.1101 ... 20217562v1
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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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COVID-19 spread is linked to atmospheric pollutants exposure

12/17/20


https://www.news-medical.net/news/20201 ... osure.aspx


The spread of SARS-CoV-2, the coronavirus responsible for the current pandemic outbreak, has been speculated to be linked to short-term and long-term atmospheric pollutants exposure, mainly particulate matters (PMs).

It is in fact possible for people living in highly industrialized areas, therefore exposed to higher pollution levels, to show more severe symptoms. Further studies have pointed out that atmospheric pollutants can act as virus carriers and boost pandemic diffusion.

A study recently published on Environmental Pollution searched for any potential short-term correlation between these two phenomena.

The research led by the Euro-Mediterranean Center on Climate Change (CMCC) Foundation and carried out in collaboration with the University of Salento and the Italian National Institute of Health (ISS) focused on the analysis of atmospheric pollutants concentrations (PM10, PM2.5, NO2) along with the spatio-temporal distribution of cases and deaths (specifically incidence, mortality and lethality rates) across the whole Italian country, down to the level of individual territorial areas, including four of the most affected regions, i.e. Lombardy, Piedmont, Emilia-Romagna and Veneto.


" The data analysis has been limited to the first quarter of 2020 to reduce the lockdown-dependent biased effects on the atmospheric pollutant levels as much as possible. Our results suggest the hypothesis of a moderate-to-strong correlation between the number of days exceeding the annual regulatory limits of PM10, PM2.5 and NO2 atmospheric pollutants and COVID-19 incidence, mortality and lethality rates for all the 107 Italian territorial areas under investigation, whereas weak-to-moderate correlations where found when the analysis was limited to four of the most affected regions in Northern Italy (Lombardy, Piedmont, Emilia-Romagna and Veneto)."

- Giovanni Aloisio, Study Corresponding Author and Professor and Member of Strategic Board, Director of the CMCC Supercomputing Center and Full Professor, Department of Innovation Engineering, University of Salento

Overall, PM10 and PM2.5 showed a higher correlation than NO2 with COVID-19 incidence, mortality and lethality rates.

Finally, PM10 profiles have been further analyzed along with the COVID-19 incidence rate variation for three of the most affected territorial areas in Northern Italy (i.e., Milan, Brescia, and Bergamo) in March 2020. All areas showed a similar PM10 time trend but a different COVID-19 incidence rate variation, that was less severe in Milan compared with Brescia and Bergamo.

The investigation will be extended in the future to account for confounding factors and outbreak dynamics, such as for example population size, ethnicity, hospital beds, number of individuals tested for COVID-19, weather, socioeconomic and behavioral variables (e.g. income, obesity, smoking habits), days since the first reported case of COVID-19, population age distribution, and days since the issuance of the stay-at-home order, etc.

The results of this study suggest in fact that confounding factors should be considered to justify why the almost identical PM10 profiles observed in Milan, Brescia, and Bergamo during the first quarter of 2020 did not produce similar COVID-19 incidence rate variations.

In addition, confounders might justify the differences in the statistical significance of correlations found when comparing a 4-region subset with the whole Italian country. Finally, climate change negatively affects human health and its potential role in the pandemic spread deserves further investigation.

Source:


CMCC Foundation - Euro-Mediterranean Center on Climate Change

Journal reference:

Accarino, G., et al. (2020) Assessing correlations between short-term exposure to atmospheric pollutants and COVID-19 spread in all Italian territorial areas. Environmental Pollution. doi.org/10.1016/j.envpol.2020.115714.
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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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Colorado study reveals potential link between air pollution and coronavirus deaths

The analysis by the Colorado Department of Public Health and Environment also underscores the disproportionate toll of COVID-19 on communities of color

2/18/21


https://coloradosun.com/2021/02/18/colo ... pollution/


Living in a community with higher rates of air pollution may be associated with a greater risk of coronavirus infection, hospitalization and death, according to a study released Thursday by the Colorado Department of Public Health and Environment.

The study also finds that there is a greater risk of coronavirus infection and severe outcomes in communities with larger proportions of people of color, higher numbers of essential workers, and higher rates of mobility.

While not yet formally peer reviewed, the research reinforces one of the most consistent findings throughout the pandemic — that inequity within Colorado and across the nation means the burden of the virus falls very differently on different communities.

“This study for us really underscores that higher rates of underlying health conditions, air pollution and worse COVID-19 outcomes go hand-in-hand with the disproportionate impact on communities of color,” said Kristy Richardson, Colorado’s state toxicologist and one of the authors of the study. CDPHE statistical analysts Kevin Berg and Paul Romer Present are also authors on the report.

But the study’s findings were also delivered with a note of caution. Richardson said measuring air pollution at the local level is difficult because there are not enough monitoring stations spread across the state. As a result, the study looked at four models that can be used to estimate fine-particle air pollution at the census-tract level. But census tracts can vary widely in size, from as small as a neighborhood in an urban area to as large as a whole rural county.

In analyses using three of the models, and taking into account things like the age of people living in the census tracts, the study found that an increase in air pollution was associated with an increase in the risk of coronavirus infection, hospitalization and death. But the results were only statistically significant for one of the models — one developed by the Environmental Protection Agency.

In the fourth model, the researchers found a non-statistically significant negative association — meaning an increase in air pollution was associated with lower COVID-19 risk.

Overall, it means the researchers can’t be conclusive about how air pollution impacts coronavirus cases.

“What we found in general is that long-term exposure to fine particles is associated with more COVID-19 infections, hospitalizations and deaths,” Richardson said. “But we don’t have enough localized pollution data to really be certain about that relationship.”

The researchers plan to submit the study for publication in a peer-reviewed journal. The study was informally reviewed by researchers at Harvard University who have conducted a similar study, as well as experts at Colorado universities.

More clear in the study is the disproportionate impact COVID-19 has on communities of color.

The researchers found that census tracts with larger proportions of Black residents were associated with a 4% greater relative risk of coronavirus infection and a 7% greater relative risk of hospitalization due to COVID-19. Census tracts with larger proportions of non-Black people of color — a group primarily made up of Hispanic Coloradans — have a 31% higher risk of infection, a 44% higher risk of hospitalization and a 59% higher risk of death.

The study also showed greater risks for neighborhoods with more essential workers and with higher levels of mobility — typically an indicator of people who cannot work from home.

Richardson said it’s difficult to disentangle all the variables. Due to social inequities, communities of color often have higher rates of chronic illness. People of color are also more likely to be essential workers and less likely to be able to work from home.

But she said the research provides valuable insight for health officials looking to use pandemic-blunting resources where they are most needed. And she said the study also shows the value in setting up more pollution-monitoring stations, something echoed by CDPHE executive director Jill Hunsaker Ryan in a statement.

“Centuries of structural discrimination in the U.S. housing system mean people of color and low-income populations often live near busy highways and industrial areas where pollution is worse,” Hunsaker Ryan said. “The resulting disproportionate harm to these communities is documented in many studies. We’ll accelerate our efforts to implement additional monitoring in areas that have higher levels of air pollution and will continue to do everything we can to ensure an equitable pandemic response.”
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Study says air pollution played a role in early U.S. COVID-19 outbreak

3/14/21


https://www.news-medical.net/news/20210 ... break.aspx


Exposure to particulate matter — a mixture of liquid and solid particles suspended in the air that ranges from dust to airborne transmission of viral droplets — has been harmful to human health. Research led by Maria de Fatima Andrade from the University of São Paulo in Brazil found particulate matter plays a significant role in increasing coronavirus cases in cities.

The authors write:

"The findings support the viral transport hypothesis, i.e., virus can associate with the preexistent particulate matter in the air synergically. We conclude that PM2.5 plays a small, yet discernible, role in the COVID-19 transmission."

The study "Exploring the short-term role of particulate matter in the COVID-19 outbreak in USA cities" is available as a preprint on the medRxiv* server, while the article undergoes peer review.

Analyzing COVID-19 case data and pollution levels

The researchers looked at the short-term relationships between particulate matter and how it contributed to COVID-19 cases in U.S. cities during the early stages of the pandemic.

They collected pollutant information from December 30, 2019, to July 31, 2020, using several datasets, including the World Air Quality Index project and the 2019 Novel Coronavirus COVID-19 (2019-nCoV) Data Repository from John Hopkins University. They matched the city-level pollution data from both datasets to county COVID-19 data. The team then narrowed their data analysis to cities with at least 80% of data available after their first case, had at least 70% of data involving particulate matter less than 1 µg to PM and nitrogen dioxide and 1 ppm to carbon monoxide.

The researchers analyzed particulate matter concentrations less than 2.5 µm and between 10 and 2.5 µm ((PM2.5 and PM10 , respectively).

A Granger causality analysis was used to find potential relationships between pollution levels instantaneous and the rate of daily COVID-19 cases in cities. They also used a logistic fitting curve to measure the number of accumulated COVID-19 cases. Lagged correlations were used to find an association between the accumulated cases and pollution's effect in influencing the spread of severe acute respiratory syndrome (SARS-CoV-2).

What they found

Results showed that having a PM2.5 concentration was associated with COVID-19 cases in 17 of 44 cities. PM2.5 was significantly higher from 0 to 18 days. Higher lags matched the incubation time for SARS-CoV-2, suggesting a PM2.5 concentration significantly impacted outbreak development.

The researchers conclude that PM2.5 greatly contributes to the coronavirus outbreak. They found that this particulate matter concentration increased the rate of COVID-19 cases in cities by 67%. This correlation was not observed with PM10.

Based on the results, the researchers suggest several explanations:

"We can describe at least three potential mechanisms underpinning these relationships: (1) long-term PM2.5 exposure increases population susceptibility; (2) PM2.5 indicates social mobility and (3) PM2.5 is a viral airborne transport facilitator. Mechanisms 1 and 2 are confounding factors to Mechanism 3."

Other pollutants, such as PM10 and nitrogen dioxide, were also linked to new COVID-19 cases, but in fewer cities. Nitrogen dioxide was linked to the rate of COVID-19 cases in 7 out of 28 cities and PM10 in 8 out of 20 cities.

Carbon monoxide was significantly linked to the rate of COVID-19 cases in 4 out of 21 locations. Carbon monoxide was also correlated with accumulated case rates with notably higher correlations after 26 days.

There was no pattern found in how the new COVID-19 cases spread throughout cities, indicating possible confounding effects such as weather and other unique regional features.

Future Work

Given the United State's diverse geographic landscape and differences in state measures during the pandemic, the researchers suggest the findings could be generalizable to other countries. They say that with more COVID-19 data, future studies would focus on the relationship between pollution levels and COVD-19 cases in cities worldwide.

"Broadly, we hope to raise the interest of the scientific community as well as the awareness of the general public and decision-makers to the potential synergy between viral transmission and air pollution," wrote the research team.

In terms of actionable items, the team says any attempt to lower the spread of COVID-19 cases in cities would help end the pandemic.

*Important Notice

bioRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.

Journal reference:

Kamigauti LY, et al. Exploring the short-term role of particulate matter in the COVID-19 outbreak in USA cities. medRxiv, 2021. doi: https://doi.org/10.1101/2021.03.09.21253212, https://www.medrxiv.org/content/10.1101 ... 21253212v1
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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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First-time direct proof of chemical reactions in particulates

3/13/21


https://phys.org/news/2020-03-first-tim ... lates.html


Researchers at the Paul Scherrer Institute PSI have developed a new method to analyse particulate matter more precisely than ever before. Using it, they disproved an established doctrine: that molecules in aerosols undergo no further chemical transformations because they are enclosed in other suspended particulate matter. In the smog chamber at PSI, they analysed chemical compounds directly in aerosols and observed how molecules dissociated and thus released gaseous formic acid into the atmosphere. These findings will help to improve the understanding of global processes involved in cloud formation and air pollution, and to refine the corresponding models. The results of this investigation are published today in the journal Science Advances.

The familiar scent of a pine forest is caused by α-pinene. This is one of the volatile organic compounds in the oils of conifer trees, and it also occurs in eucalyptus and rosemary. The smell triggers pleasant feelings in most people. Less pleasant is that under the influence of radicals, the compound changes into other compounds in the atmosphere, so-called highly oxidised organic molecules. Some of these are reactive and to some extent harmful substances. They have only recently come under scrutiny by atmospheric researchers, and their role in cloud formation is not yet understood.

These highly oxidized organic molecules are less volatile than the starting substance α-pinene and therefore condense easily. Together with dust particles and other solid and liquid substances in the air, they form what we call particulate matter or aerosols.

"Up to now, it was thought that such molecules are protected from further transformations once they have landed in particulate matter," says Andre Prévôt of the Laboratory of Atmospheric Chemistry at PSI. "It was believed that they then would not change any more, but would simply spread out over the atmosphere and eventually rain down."

This widespread opinion does not correspond to reality, however, as Prévôt and his fellow researchers at PSI showed: "The reactions continue, even in the particulate matter." The molecules remain reactive and either react with each other to form larger particles or disassociate, thereby releasing for example formic acid. This common compound is found not only in ants and stinging nettles, but also in the atmosphere, where it is an important indicator of air pollution.

The PSI researchers' observations should help to improve simulation models, such as those for cloud formation and air pollution. The models simulate what happens in the atmosphere to predict, for example, how a reduction in certain emissions will affect air quality.

From the aerosol into the measuring device


For the first time, PSI researchers analysed chemical compounds directly in particulate matter under atmospheric conditions. For this, they used the PSI smog chamber, in which processes in the atmosphere can be simulated. The researchers injected a droplet of α-pinene into the chamber and caused the compound to react with ozone. Over a period of 15 hours, they observed which chemical compounds formed from α-pinene and which disappeared again afterwards.

This was made possible by a new analytic device for atmospheric measurements that the researchers developed in cooperation with the company Tofwerk in Thun, Switzerland: a so-called EESI-TOF (extractive electrospray ionisation time-of-flight mass spectrometer). "It also detects larger molecules directly in the aerosol," explains atmospheric chemist Urs Baltensperger. "Previous measurement methods, on the other hand, chop up the molecules into smaller fragments at high temperatures." The new device ionises without fragmentation. "We can record each molecule separately."

Tofwerk has now brought the device to market with the help of PSI, so that other atmospheric researchers can also benefit from the new method.

Measurements in Zurich

The new analytic method can be used not only in the laboratory, but also directly on site. During the winter of 2018/19 and the summer of 2019, PSI researchers used it to investigate aerosols in the air in Zurich. As it turned out, a good third of Zurich's particulate matter in summer consists solely of reaction products of α-pinene and similar molecules. In winter, however, emissions from wood-burning systems and their reaction products come to the fore.

The researchers have planned further measurement campaigns in China and India. There they want to analyse which molecules form in the air of a city with more than a million inhabitants.

More information:
"On the fate of oxygenated organic molecules in atmospheric aerosol particles" Science Advances (2020). advances.sciencemag.org/content/6/11/eaax8922

Felipe D. Lopez-Hilfiker et al. An extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF) for online measurement of atmospheric aerosol particles, Atmospheric Measurement Techniques (2019). DOI: 10.5194/amt-12-4867-2019

Giulia Stefenelli et al. Organic aerosol source apportionment in Zurich using an extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF-MS) – Part 1: Biogenic influences and day–night chemistry in summer, Atmospheric Chemistry and Physics (2019). DOI: 10.5194/acp-19-14825-2019

Lu Qi et al. Organic aerosol source apportionment in Zurich using an extractive electrospray ionization time-of-flight mass spectrometer (EESI-TOF-MS) – Part 2: Biomass burning influences in winter, Atmospheric Chemistry and Physics (2019). DOI: 10.5194/acp-19-8037-2019
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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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Particulates are more dangerous than previously thought

3/19/21


https://phys.org/news/2021-03-particula ... ought.html


Researchers at the Paul Scherrer Institute PSI have for the first time observed photochemical processes inside the smallest particles in the air. In doing so, they discovered that additional oxygen radicals that can be harmful to human health are formed in these aerosols under everyday conditions. They report on their results today in the journal Nature Communications.

It is well known that airborne particulate matter can pose a danger to human health. The particles, with a maximum diameter of ten micrometers, can penetrate deep into lung tissue and settle there. They contain reactive oxygen species (ROS), also called oxygen radicals, which can damage the cells of the lungs. The more particles there are floating in the air, the higher the risk. The particles get into the air from natural sources such as forests or volcanoes. But human activities, for example in factories and traffic, multiply the amount so that concentrations reach a critical level. The potential of particulate matter to bring oxygen radicals into the lungs, or to generate them there, has already been investigated for various sources. Now the PSI researchers have gained important new insights.

From previous research it is known that some ROS are formed in the human body when particulates dissolve in the surface fluid of the respiratory tract. Particulate matter usually contains chemical components, for instance metals such as copper and iron, as well as certain organic compounds. These exchange oxygen atoms with other molecules, and highly reactive compounds are created, such as hydrogen peroxide (H2O2), hydroxyl (HO), and hydroperoxyl (HO2), which cause so-called oxidative stress. For example, they attack the unsaturated fatty acids in the body, which then can no longer serve as building blocks for the cells. Physicians attribute pneumonia, asthma, and various other respiratory diseases to such processes. Even cancer could be triggered, since the ROS can also damage the genetic material DNA.

New insights thanks to a unique combination of devices


It has been known for some time that certain reactive oxygen species are already present in particulates in the atmosphere, and that they enter our body as so-called exogenous ROS by way of the air we breathe, without having to form there first. As it now turns out, scientists had not yet looked closely enough: "Previous studies have analyzed the particulate matter with mass spectrometers to see what it consists of," explains Peter Aaron Alpert, first author of the new PSI study. "But that does not give you any information about the structure of the individual particles and what is going on inside them."

Alpert, in contrast, used the possibilities PSI offers to take a more precise look: "With the brilliant X-ray light from the Swiss Light Source SLS, we were able not only to view such particles individually with a resolution of less than one micrometer, but even to look into particles while reactions were taking place inside them." To do this, he also used a new type of cell developed at PSI, in which a wide variety of atmospheric environmental conditions can be simulated. It can precisely regulate temperature, humidity, and gas exposure, and has an ultraviolet LED light source that stands in for solar radiation. "In combination with high-resolution X-ray microscopy, this cell exists just one place in the world," says Alpert. The study therefore would only have been possible at PSI. He worked closely with the head of the Surface Chemistry Research Group at PSI, Markus Ammann. He also received support from researchers working with atmospheric chemists Ulrich Krieger and Thomas Peter at ETH Zurich, where additional experiments were carried out with suspended particles, as well as experts working with Hartmut Hermann from the Leibniz Institute for Tropospheric Research in Leipzig.

How dangerous compounds form


The researchers examined particles containing organic components and iron. The iron comes from natural sources such as desert dust and volcanic ash, but it is also contained in emissions from industry and traffic. The organic components likewise come from both natural and anthropogenic sources. In the atmosphere, these components combine to form iron complexes, which then react to so-called radicals when exposed to sunlight. These in turn bind all available oxygen and thus produce the ROS.

Normally, on a humid day, a large proportion of these ROS would diffuse from the particles into the air. In that case it no longer poses additional danger if we inhale the particles, which contain fewer ROS. On a dry day, however, these radicals accumulate inside the particles and consume all available oxygen there within seconds. And this is due to viscosity: Particulate matter can be solid like stone or liquid like water—but depending on the temperature and humidity, it can also be semi-fluid like syrup, dried chewing gum, or Swiss herbal throat drops. "This state of the particle, we found, ensures that radicals remain trapped in the particle," says Alpert. And no additional oxygen can get in from the outside.

It is especially alarming that the highest concentrations of ROS and radicals form through the interaction of iron and organic compounds under everyday weather conditions: with an average under 60 percent and temperatures around 20 degrees C., also typical conditions for indoor rooms. "It used to be thought that ROS only form in the air—if at all—when the fine dust particles contain comparatively rare compounds such as quinones," Alpert says. These are oxidized phenols that occur, for instance, in the pigments of plants and fungi. It has recently become clear that there are many other ROS sources in particulate matter. "As we have now determined, these known radical sources can be significantly reinforced under completely normal everyday conditions." Around every twentieth particle is organic and contains iron.

But that's not all: "The same photochemical reactions likely takes place also in other fine dust particles," says research group leader Markus Ammann. "We even suspect that almost all suspended particles in the air form additional radicals in this way," Alpert adds. "If this is confirmed in further studies, we urgently need to adapt our models and critical values with regard to air quality. We may have found an additional factor here to help explain why so many people develop respiratory diseases or cancer without any specific cause."

At least the ROS have one positive side—especially during the COVID-19 pandemic—as the study also suggests: They also attack bacteria, viruses, and other pathogens that are present in aerosols and render them harmless. This connection might explain why the SARS-CoV-2 virus has the shortest survival time in air at room temperature and medium humidity.

More information:
Photolytic Radical Persistence due to Anoxia in Viscous Aerosol Particles, Nature Communications, DOI: 10.1038/s41467-021-21913-x
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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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COVID-19 pandemic provides a wake-up call to control air pollution

4/7/21


https://www.news-medical.net/news/20210 ... ution.aspx


A new commentary published online in the Annals of the American Thoracic Society provides an exhaustive examination of published research that discusses whether air pollution may be linked to worse COVID-19 outcomes. The studies that the authors examined look at several potential disease mechanisms, and also at the relationship between pollution, respiratory viruses and health disparities.

In "COVID-19 Pandemic: A Wake-Up Call for Clean Air," Stephen Andrew Mein, MD, Department of Medicine, Beth Israel Deaconess Medical Center, Boston, and colleagues discuss several ways that the COVID-19 pandemic highlights the urgent need to address the global problem of air pollution through sustainable local and national policies to improve respiratory health and equity worldwide. More than 91 percent of the world's population lives in areas that exceed the World Health Organization's air quality guidelines and more people are impacted by worsening air quality each year.

The commentary focuses on the health effects of ambient air pollution. Ambient air pollution consists of potentially harmful pollutants, such as small particles and toxic gases, emitted by industries, households, cars and trucks. International studies have shown that exposure to these pollutants worsens viral respiratory infections and new studies are showing a similar association with ambient pollution and COVID-19 outcomes.


" There are a multitude of studies showing that exposure to higher long-term ambient air pollution is associated with both increased risk of infection and death from COVID-19. Historically, air pollution has been linked with worse outcomes, including higher mortality, due to other respiratory viruses like influenza."

- Dr. Stephen Andrew Mein, MD, Department of Medicine, Beth Israel Deaconess Medical Center, Boston

He added, "Research that we examined on pollution during the COVID-19 pandemic has found similar detrimental effects. New research on COVID-19 adds further evidence of the adverse effects of ambient air pollution and the urgent need to address the public health crisis of pollution."

One of the most prominent studies that the authors examined, in which COVID-19 mortality was modeled, found that each small (1 mg/m3) increase in long-term fine inhalable particle (PM2.5) exposure was associated with an 8 percent increase in mortality during the pandemic. Another study concluded that air pollution has contributed 15 percent to COVID-19 mortality worldwide.

"The studies we reviewed evaluated whether long-term, ambient air pollution exposure that occurred years prior to the pandemic was associated with worse COVID-19 outcomes," Dr. Mein stated.

The exact mechanisms for the association between long-term pollution and poor COVID-19 outcomes are not fully known. However, scientists have suggested several theories. Long-term exposure to air pollution may impair the immune system, leading to both increased susceptibility to viruses and more severe viral infections. Higher air pollution exposure is associated with higher rates of heart disease and metabolic disorders such as diabetes, which are known to be risk factors for severe disease and death from COVID-19. These chronic effects would have occurred prior to the reported reductions in air pollution since the start of the COVID-19 pandemic.

A major point of the authors' commentary is that improved air quality (due to less travel and industrial activity) during the pandemic may have reduced morbidity and mortality from non-communicable diseases. "Research evaluating associations between the dramatic reduction in ambient air pollution during the global lockdowns and health care utilization for respiratory conditions would further confirm the impact of ambient air pollution on non-communicable diseases and the need to reduce air pollution to improve overall health."

The authors also noted that much of the research about ambient air pollution and the COVID-19 pandemic is just emerging. "While the primary association between air pollution and COVID-19 outcomes has been generally consistent, there is still much research to be done. In particular, there is a need for studies that adjust for individual-level risk factors, since current studies have been restricted to county or municipal-level exposure and outcome data. Research also needs to be conducted to evaluate whether air pollution is contributing to the stark differences in COVID-19 outcomes among minority groups."

Racially and ethnically diverse communities are more likely to be located in areas closer to industrial pollution such as PM2.5 and nitrogen dioxide, and to work in types of businesses that expose them to more air pollution. These inequalities in residential and occupational air pollution exposure may be one of the causes of the stark disparities of the COVID-19 pandemic along racial and ethnic lines.

In conclusion, the authors state, "The COVID-19 pandemic has highlighted the widespread health consequences of ambient air pollution, including acute effects on respiratory immune defenses and chronic effects that lead to higher risk of chronic cardiopulmonary disease and acute respiratory distress syndrome (ARDS). These chronic health effects likely explain the higher COVID-19 mortality among those exposed to more air pollution. The pandemic has also provided a glimpse into the health benefits of cleaner air. As we emerge from this devastating public health crisis, COVID-19 is a wakeup call for the need to adopt stricter air quality standards and end our tolerance for pollution in disadvantaged neighborhoods. As part of our post-COVID-19 recovery, we must clean up the air to improve respiratory health and equality worldwide."

Source:

American Thoracic Society (ATS)

Journal reference:


Mein, S.A., et al. (2021) COVID-19 Pandemic: A Wake-Up Call for Clean Air. Annals of the American Thoracic Society. doi.org/10.1513/AnnalsATS.202012-1542VP.
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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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How much does air pollution amplify COVID-19 severeness?

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Re: About 15% of COVID-19-related deaths linked to long-term exposure to air pollution

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Research finds highest COVID-19 death rates in Los Angeles County neighborhoods with poor air quality

4/15/21


https://www.news-medical.net/news/20210 ... ality.aspx


A research project led by the UCLA Fielding School of Public Health has found that Los Angeles County neighborhoods with poor air quality had the highest death rates from the pandemic.

" Our findings imply a potentially large association between exposure to air pollution and population-level rates of COVID-19 cases and deaths. These findings are especially important for targeting interventions aimed at limiting the impact of COVID-19 in polluted communities."

- Dr. Michael Jerrett, Fielding School professor of environmental health sciences and the project's leader

The research – "Spatial Analysis of COVID-19 and Traffic-related Air Pollution in Los Angeles" - is being published in the upcoming August, 2021 edition of the peer-reviewed journal Environment International, and is now available on-line. One example of the findings: Los Angeles County neighborhoods with the worst air quality saw a 60% increase in COVID-19 fatalities, compared with communities with the best air quality.

"In the U.S., more polluted communities often have lower incomes and higher proportions of Black and Latinx people. In addition, Black and Latinx people have higher rates of pre-existing conditions, potentially further exacerbating the risk of COVID-19 transmission and death," said co-author Jonah M. Lipsitt, a PhD candidate and researcher with the Fielding School's UCLA Center for Healthy Climate Solutions. "The elevated risk of case incidence and mortality observed in these populations may result, in part, from higher exposure to air pollution."

The research team, from UCLA's Fielding School (FSPH), the University of California, Berkeley, and the University of California, Merced, analyzed the relationship of air pollution and COVID-19 case incidence, mortality, and case-fatality rates in neighborhoods of Los Angeles County. They focused on nitrogen dioxide (NO2) because the pollutant serves as a marker for traffic-related air pollution, or TRAP, generally.

"We know that TRAP is associated with many respiratory morbidities, including asthma, chronic pulmonary disease, lung cancer, and respiratory tract infections, as well as hospitalizations, mortality, and an increased risk of respiratory viral infection," said Dr. Yifang Zhu, FSPH professor of environmental health sciences and senior associate dean for academic programs. "Nitrogen dioxide, for example, has been found to impair the function of alveolar macrophages and epithelial cells, thereby increasing the risk of lung infections."

The work reaches down to the city- and neighborhood-level in Los Angeles County, home to more than 10 million people, a population larger than 40 U.S. states.

"Los Angeles is one of the only metropolitan cities globally to publicly report neighborhood-level COVID-19 cases and mortality," said co-author Dr. Alec M. Chan-Golston, an assistant professor at UC Merced. "These data gave us the opportunity to study a large population, but at a "neighborhood-level, which allows for more accurate pollution exposure estimates."

The researchers have benefitted from exhaustive records related to the pandemic made public by the city of Los Angeles and the Los Angeles County Department of Public Health (LACDPH). The local focus, however, does not mean the findings are of interest only to Angelenos, Lipsett said.

"Los Angeles is a global epicenter for the pandemic with more than 1.1 million cases to date, but our key conclusion?" he said. "Long-term air pollution exposure, anywhere, is likely to increase the risk of COVID-19 infection and death."

Methods: Researchers used data from the Los Angeles County Department of Public Health (LACDPH) and the American Community Survey (ACS), produced by the U.S. Census Bureau. This data was compared with statewide air quality data from 2016.

The original study period captured approximately the first six months of the pandemic (March 16th to September 8th, 2020); it was expanded to the subsequent six months (September 8th, 2020 to February 23rd, 2021). This replicated analysis for the subsequent 6-month period had nearly four times the incident cases (875,368 cases) as the first period (230,621 cases).

In comparing the two time periods, before and after September 8th, 2020, researchers found that the results were largely consistent, despite very different case numbers, testing regimes, and improvements in classifying deaths. While some differences exist in the size of the effects, overall the conclusions remain the same.

Source:

UCLA Fielding School of Public Health

Journal reference:


Lipsitt, J., et al. (2021) Spatial analysis of COVID-19 and traffic-related air pollution in Los Angeles. Environment International. doi.org/10.1016/j.envint.2021.106531.
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