New connections between air pollution, CVD and mortality

reference

Wang B, Eum KD, Kazemiparkouhi f, et al. The effects of long-term PM 2.5 exposure to certain causes of death: exposure-effect curves and effect modification in 53 million US Medicare recipients. Environmental health . 2020; 19 (1): 20.

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observation. The researchers used hybrid machine learning and COX-proportional hazard models to evaluate the association of long-term exposure to fine dust _{2.5 (fine dust with a width of 2.5 micrometers or less) with certain causes of death.}

participant

fifty-three million (53,000,000) US Medicare recipients (aged ≥ 65 years) from 2000 to 2008 with around 4 billion person months of follow-up.

pollution

The researchers calculated the PM exposure 2.5 by a combination of Environmental Protection Agency (EPA), Meteorological and Geo-Age models that are applied to the address and postal code of each participant.

target parameter

Disease -specific and total mortality.

important knowledge

PN 2.5 was associated with increased mortality due to cardiovascular diseases (CVD), respiratory diseases and cancer (with the exception of lung cancer). A 10 μg/m 3 increase in the average PM 2.5 in the 12 months before death was with a 5 %increase in total mortality and an 8.8 %increase in the entire cardiovascular mortality, a 5.6 %increase in the entire respiratory trace -related mortality and a 2.5 %increase in all cancer -related Deaths in models, adapted to age, gender, breed, postcode and socio -economic status (SES). However, PN 2.5 exposure were not associated with lung cancer mortality. The results were not sensitive to controls for ozone loads. PN 2.5 mortality associations for cardiovascular and respiratory causes were positive and significant for the beneficiaries, regardless of gender, breed, age, SES and urbanity, without references to a lower threshold for response or lower risk relationships (RRS) at low PN levels. Associations between PM 2.5 and cardiovascular and respiratory mortality were linear and higher for younger, black and urban beneficiaries, but were largely similar according to SES.

practice implications

This study, together with the recent meta-analysis by Pranata et al. ¹ , was particularly relevant when we were in a lockdown reaction to the Covid 19 pandemic. dramatic worldwide.

The result is that we have become participants in a global experiment, a global cohort that tests whether lower air pollution is associated with improved health, lower morbidity and a reduction in mortality, especially through cardiovascular diseases. Air pollution decreased dramatically when each country introduced blocking measures to slow down the spread of Covid-19

The work of Pranata et al. was published on March 13, 2020 in Journal for Evidence -based Medicine . It is a comprehensive review and meta-analysis of previous studies on air pollution and mortality from cardiovascular diseases. Data from 84 cohorts with a total of 28,215,394 subjects were combined. Increases in fine dust air pollutants were associated with climbs at all measurements of CVD, acute coronary events, stroke and high blood pressure. The mortality rate of CVD increased by 10 % for the PM 2.5 and 17 % if the larger PM 10

Air pollution went back dramatically when every country introduced locking measures to slow down the spread of Covid-19.

Noteworthy is also a work by Hayes et al. from July 2019, which reports that 10 μg/m 3 increase of the pm 2.5 4 Each of these papers would be sufficient to predict that the decline in air pollution as a result of the response to COVID-19 could influence the current disease rates.

The determination of Wang et al. The fact that mortality caused by lung cancer is not related to air pollution was not unexpected. Earlier studies have also reported a similar zero effect, ^{5 Although others have seen a positive association.}

The area of ​​the forecast numbers from the worsening air quality, which we find in this brief overview, ranges from 5 % (Wang et al.) to an increase in cardiovascular mortality by 10 % (Pranata et al.) To 16 % increase in mortality due to ischemic heart disease (Hayes et al.). Although a few years older, the study by Pope et al. from 2015 that a similar increase in fine dust concentration was accompanied by a 12 percent increase in CVD deaths.

These results offer a clue to estimate what we could see in future statistics that look back on this period in terms of cardiovascular mortality.

In an article that was published on the academic website G-Feed at the beginning of March, Marshall Burke, Professor at the Earth System Science Department in Stanford, calculated that the reduced air pollution in China may have saved 20 times more life in China last winter. Chinese research; Neither the results of Pranata nor Wang had been published when he did his calculations.

Burke used the results of Su et al. from 2016 and data collected during the 2008 Summer Olympics and Paralympic Games. Remember how China made great efforts to reduce air pollution during the games by restricting traffic. ^{10 Burke estimated that this was "approximately 10 ug/m 3 reduction of fine dust pollution in the whole of China from January to February 2020 compared to the same months in the previous two years." Guojun He et al. had reported "that a reduction in concentrations by 10 % reduces the monthly standardized mortality rate of all causes by 8 %".}

Burke writes: "If you summarize these numbers ... there is a very large reduction in premature mortality ... I expect that for 2 months you have 10 ug/m 3 reduction of the PM 2.5 probably has 4,000 children under 5 years and 73,000 adults over 70 years in China."

The United States started with much cleaner air than China, so these relationships may not be valid. But as already mentioned, Wang et al. "No indications of a lower threshold for the response or lower risk conditions (RRS) at low PM 2.5 levels." This indicates that the reduction of our own degrees of pollution can still lead to significant improvements.

Around 647,000 people die from CVD every year in the United States. ^{12 If our stay in the home would reduce this number by 10 % (a conservative estimate), this would prevent almost 65,000 deaths solely by cardiovascular diseases, a change that would be noticeable. The decline of Pranata et al. by 16 % would mean over 103,000 saved life.}

In earlier editions of nmj We have checked numerous studies that have associated PM 2.5 Exposure with various measures for health and illness. In the coming months and years we may see more precise measurements of the true effects of air pollution and may be able to calculate your costs for municipal health.

Unfortunately, our experiment can be confused by other simultaneous events. The EPA is currently resigning the regulations for the enforcement of pollution, and it can be difficult to take into account the damage that these returns can cause if they are weighed against the health improvements by cleaner air. The loss of the workplace and the associated changes that unemployment on the effects on heart health must also be taken into account.

When we crouched during the orders for staying at home, a second unplanned experiment in connection with climate change took place. The CO2 emissions have dropped dramatically. An abrupt stop of Chinese industrial production apparently reduced its CO2 emissions at the beginning of this year.

Time will show it, but in the meantime those of us who live in urban areas can enjoy cleaner air and a clearer sky, even if this only happened from our veranda and our back terrace.