Emission Impossible Ltd


Archive for October, 2021

Long-term exposure to PM10 above WHO guidelines exacerbates COVID-19 severity and mortality

Marques M., Correiq E., Ibarretxe D., Anoro E., Arroyo JA., Jerico C., Borralo R., la Miret M., Naf S., Pardo A., Perea V., Perez-Bernalte R., Ramirez-Montesinos R., Royuela M., Soler C., Urquizu-Padilla M., Zomora A., Pedro-Botet J., Domingo J.


  • The severity and mortality of COVID-19 is predicted by long-term exposure to PM10.
  • PM10 is a more important variable than some already stated comorbidities.
  • The higher the PM10 concentration the higher the number of severe COVID-19 cases.
  • The higher the PM10 concentration the higher the number of COVID-19 deaths.


Age, sex, race and comorbidities are insufficient to explain why some individuals remain asymptomatic after SARS-CoV-2 infection, while others die. In this sense, the increased risk caused by the long-term exposure to air pollution is being investigated to understand the high heterogeneity of the COVID-19 infection course.


We aimed to assess the underlying effect of long-term exposure to NO2 and PM10 on the severity and mortality of COVID-19.


A retrospective observational study was conducted with 2112 patients suffering COVID-19 infection. We built two sets of multivariate predictive models to assess the relationship between the long-term exposure to NO2 and PM10 and COVID-19 outcome. First, the probability of either death or severe COVID-19 outcome was predicted as a function of all the clinical variables together with the pollutants exposure by means of two regularized logistic regressions. Subsequently, two regularized linear regressions were constructed to predict the percentage of dead or severe patients. Finally, odds ratios and effects estimates were calculated.


We found that the long-term exposure to PM10 is a more important variable than some already stated comorbidities (i.e.: COPD/Asthma, diabetes, obesity) in the prediction of COVID-19 severity and mortality. PM10 showed the highest effects estimates (1.65, 95% CI 1.32-2.06) on COVID-19 severity. For mortality, the highest effect estimates corresponded to age (3.59, 95% CI 2.94-4.40), followed by PM10 (2.37, 95% CI 1.71-3.32). Finally, an increase of 1 µg/m3 in PM10 concentration causes an increase of 3.06% (95% CI 1.11%-4.25%) of patients suffering COVID-19 as a severe disease and an increase of 2.68% (95% CI 0.53%-5.58%) of deaths.


These results demonstrate that long-term PM10 burdens above WHO guidelines exacerbate COVID-19 health outcomes. Hence, WHO guidelines, the air quality standard established by the Directive 2008/50/EU, and that of the US-EPA should be updated accordingly to protect human health.

[Source: Environment International]

Auckland needs its schools to reopen. Here’s what must happen first

The final term of the year begins today, with children in Tāmaki Makaurau resuming remote learning. Paediatrician Dr Jin Russell outlines a gold standard plan for safely reopening.

In Auckland, a date for reopening schools is expected to be announced soon. Everyone wants reopening schools to be as safe as possible, both for students and for staff. We need a public-facing gold-standard, evidence-based plan for reopening schools in Auckland. The good news is that the government is not too far from being able to achieve this.

One of the successes of New Zealand’s elimination strategy has been that schools have mostly stayed open. In an elimination state, children do well because they experience little harms from the pandemic. But in a suppression strategy, such as we now appear to have in Auckland, doing our best for children involves protecting them from both the direct harms of Covid-19 – being infected with the virus – and the indirect harms of Covid-19: prolonged school closures, isolation, financial stress, and sick family members and friends. 

Firstly, it’s important to summarise how Covid-19 infection affects children. Without good information, many families may be so anxious that they may wish to keep their children home indefinitely leading to absenteeism and educational harm. That’s not a good outcome either.

How children are affected by Covid

The majority of children who are infected with Covid-19 experience a mild or asymptomatic illness, and severe illness is rare. During the New South Wales winter delta outbreak, 2,864 children were infected, and of these 1.5% were hospitalised. Paediatricians in Australia have reassured that the majority of these hospitalisations are minor events, often for rehydration, or a brief stay on the ward for oxygen. Of the 2,684 children, 0.2% needed intensive care, and these were all young people aged 15-18 years old who were, sadly, unvaccinated. Severe illness is rare among children.

While this is reassuring for some parents, we need to take a whole-of-population view – an epidemiological view. Children who have pre-existing conditions are at increased risk of more serious illness, and this can be thought of as similar to the risk posed by other respiratory viruses such as RSV and influenza. We would also expect hospitalisations to be inequitably distributed, such that children in more disadvantaged neighbourhoods do worse. So even with a low overall hospitalisation rate, if we allowed unfettered community transmission, we would expect a surge of paediatric hospitalisations, and this would put pressure on the health system (think of this year’s RSV surge) and would be unacceptably inequitable. We didn’t close ECEs during the RSV surge this year, and we don’t close schools every winter when the typical respiratory viruses go around. But, in general, parents and paediatricians are keen to see lower levels of all of these respiratory viruses in children.

There’s also the unknown of persisting symptoms after Covid-19 infection in children, commonly referred to as Long Covid. This phenomenon appears to be less frequent, and milder, and of shorter duration than in adults. However, while research is ongoing, it’s a good idea to protect children from being exposed to the virus in large numbers.

Prolonged school closures are harmful for children. Schools do far more than provide formal education. They are essential services for children’s wellbeing, learning, development, mental health and friendships.

This is why a gold-standard plan for reopening schools is needed. A gold standard plan is a win-win. Not only will it protect children, teachers, and their households from Covid-19, it will help to keep schools open. Without rock-solid mitigations in place, we risk outbreaks, rolling school closures, with knock-on effects on parents” confidence in sending their children to school.

In Australia, Victoria produced a plan for reopening schools which has been praised by paediatricians and experts. It involves three protections: Vaccination, Ventilation and Filtration, and “Vital CovidSAFE steps” such as hygiene, distancing and masking.

Why vaccination matters so much in schools

Like Victoria, it is mandatory for all New Zealand school staff who work with children and students to be fully vaccinated by January 1 2022. Because infected adults transmit delta more readily than children do within school settings, a highly vaccinated school workforce will make it harder for delta to spread within schools. In one New South Wales study of delta transmission within schools and ECEs, the proportion of infected children who transmitted the virus to a close contact within the school setting was only 1.6%. In the same study, 11.2% of infected adults transmitted to another adult within the educational setting, and 7% of infected adults transmitted to one child or more.

Infected children can transmit Covid-19 to their household bubbles, including more vulnerable adults. Older adolescents tend to transmit more like adults because of the biological continuum. 

The answer to preventing this is, of course, vaccination. Reopening schools presents an opportunity to reach those unvaccinated families who have not yet been reached through the vaccine rollout. When schools are reopened, we should couple this with a push to vaccinate all eligible young people and unvaccinated family members on site. This will also protect teachers.

The role of ventilation and filtration

Ventilation and filtration are key components of the Victorian school reopening plan. These protections are so important because the delta variant spreads through airborne transmission. Microscopic virus-laden particles can float through the air over several metres and accumulate in poorly-ventilated spaces. Maximising natural ventilation through opening windows and doors, to bring as much outdoor air in as possible, is crucial. 

But where Victoria has really gone above and beyond is in the provision of 51,000 air purifiers with high efficiency particulate air (HEPA) filters. These HEPA filters are capable of removing 99.9% of human-generated SARS-CoV-2 virus particles from the air. They are used more commonly in high risk settings such as medical wards and MIQ facilities and in schools overseas. There is some cost to purchasing these units, but this cost needs to be balanced against the social and economic impact of rolling school outbreaks and school closures. Victoria has made the calculation.

Not all New Zealand schools were built with ventilation in mind, and some classrooms will be harder to ventilate naturally than others. We don’t have a great track record on ventilation in schools. The Victorian plan includes ventilation audits and the use of CO2 monitors. Portable CO2 monitors are an inexpensive tool that can be used to identify which classrooms are harder to ventilate. Audits may inform room occupancy plans, and where to put air purifiers.

A government initiative that provides all schools with air purifiers and CO2 monitors for auditing would likely be very popular with schools and parents. If we leave the provision of such portable air cleaners to schools themselves, what do we expect to happen? Private and well-resourced schools will purchase these protections themselves, while less resourced schools, arguably at higher risk of outbreaks, will be left behind.

Getting more serious about ventilation and clean air is the way forwards now that delta has taken root. Not only does better ventilation and cleaner air protect children from Covid-19, air purifiers are also able to clean out Staphylococcus, Streptococcus, and other viruses from the air. They would also be helpful in the event of severe Australian or New Zealand bushfires.

In New Zealand, we are not far from being able to achieve a gold standard school reopening plan like Victoria. Schools are putting in an incredible effort to plan for this. Their efforts can be maximised by the government taking school reopening plans to the next level.

The government can front-foot clean air initiatives for schools, just as it has been bold on vaccine mandates. This would be a win-win for child health and education. A gold standard school reopening plan, that includes resources for cleaner air, and vaccination on-site, would give the public confidence that the government is committed to doing its very best for children’s health and to keeping schools open as much as possible in the pandemic.

Dr Jin Russell is a developmental paediatrician in Auckland, and a PhD student in life-course epidemiology at the University of Auckland. She is a former member of the NZ Policy and Advocacy Committee and College Council of The Royal Australasian College of Physicians.

[Source: The Spinoff]

Air pollution linked to millions of birth complications across the globe







Scientists estimate millions of preterm births and underweight newborns worldwide can be attributed to long-term exposure to air pollution.

Every year, an estimated seven million people die from air pollution across the globe. Now, new research shows that air pollution is not only a health threat to everyone in the world, but also to those who have not yet arrived.

The study, published today in the journal PLOS Medicine, looked into the pernicious impact of air pollution on birth outcomes worldwide. After analyzing available data from all inhabited continents, the researchers estimated that exposure to PM2.5—pollutant particles with widths 30 times smaller than a human hair—was linked to almost six million premature births and roughly three million underweight babies across the world in 2019.

The findings are “staggering,” Rakesh Ghosh, an environmental epidemiologist at University of California, San Francisco, and the lead author of the study, told EHN.

Air pollution and birth outcomes are both prevalent global health concerns. Nine out of 10 people in the world breathe polluted air. Meanwhile, every year, about 15 million babies are born preterm, and approximately 20 million newborns are delivered underweight. Preterm birth complications are the leading cause of death among children under 5-years-old, while babies with low birth weight suffer increased risk for noncommunicable diseases, such as diabetes and cardiovascular disease, later in life.

The smallest class of inhalable particles, PM2.5 permeates both indoor and outdoor air. Sources of PM2.5 range from vehicle emission burning fuels, forest fires, and chemical plant exhaust to cooking, smoking, burning candles, and fireplaces. Once inhaled, PM2.5, with particle sizes of 2.5 micrometers or smaller, can easily travel deep into the lungs.

While the link between PM2.5 and adverse pregnancy outcomes is well-established, global assessment of the issue still remains sparse. This study is believed to be the first to investigate the relationships between indoor and outdoor PM2.5 pollution and key pregnancy indicators—such as gestational age at birth, reduction in birth weight, low birth weight, and preterm birth—worldwide.

“It’s not like air pollution has borders,” Rupa Basu, a research epidemiologist and Chief of Air and Climate Epidemiology Section at California Environmental Protection Agency (CalEPA), who was not involved in the study, told EHN. By widening the research worldwide, Basu said that this study “opens the door to say, ‘yes, there is consistent evidence'” when connecting the dots between adverse birth outcomes and long-term PM2.5 exposure.

Birth outcomes and environmental injustice 

Scientists are still trying to piece together how PM2.5 affects the fetus. Previous research has shown that air pollution particles can reach the fetal side of the placenta, while other studies have found pollution to impact the blood flow, oxygen exchange, and nutrient transportation between the mother and the baby. As a result, the fetus may experience delayed development or elevated inflammation.

The study also found that though air pollution burdens neonatal health worldwide, less developed countries in South Asia and Sub-Saharan Africa have significantly more problems compared to wealthy western countries.

“There is a tremendous discrepancy, no matter which [birth] outcome you look at,” Ghosh said. Take birth weight reduction: While babies in South Asia and Sub-Saharan Africa were estimated to experience an average of more than 110 grams (3.8 ounces) of weight reduction due to PM2.5, the estimation for North America and Western Europe babies was only 11 grams (.39 ounces).

CalEPA’s Basu is not surprised by the disparity. Pollution, environmental justice, and socioeconomic status are “kind of tied together,” she said. “You can’t really look at one without looking at the other.”

Regulatory reforms 

Currently, the U.S. Environmental Protection Agency still classifies PM2.5 as a risk factor for adverse health effects that is “suggestive of, but not sufficient to infer, a causal relationship.” The pollutant is classified similarly by most other regulatory agencies in the world.

Tim Nawrot, an environmental epidemiology professor at Hasselt University in Belgium who was not involved in this study, thinks the strength of this study is translating science and statistics from all over the world into something “many communities and policymakers…would otherwise not have seen.”

“Science has provided the full translation,” he told EHN. “Policymakers have to pick it up and do something with it.”

[Source: Environmental Health News]