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New research finds a strong correlation between toxic and nontoxic pollution in some countries. CHAIDEER MAHYUDDIN/AFP via Getty Images
  • Humanity has produced significant amounts of both toxic and nontoxic pollution.
  • Toxic pollution, such as fine particulate matter, directly harms human health.
  • Nontoxic pollution contributes to global heating, which consequently damages human health due to the negative effects of climate change.
  • Toxic and nontoxic pollution can exacerbate one another.
  • The present study shows a “strong correlation” between toxic and nontoxic pollution in specific countries.
  • The study also highlights a list of 10 countries that are most at risk of climate change and toxic pollution.

In a new study, researchers have demonstrated a “strong correlation” between toxic pollution, which directly damages human health, and nontoxic pollution, which contributes to global heating and climate change.

In the study, published in the journal PLOS ONE, the researchers identified countries that the international community can effectively support to reduce the negative effects of both types of pollution.

The researchers also identified countries that will require support to “address governance challenges in order to have a chance at successfully addressing pollution risk,” says Dr. Richard Marcantonio from the Kroc Institute for International Peace Studies, University of Notre Dame, IN, and his study co-authors.

Human pollution has had a profound negative effect on ecologies across the world. This pollution originates from toxic emissions — such as fine particulate matter, or PM2.5 — and nontoxic emissions, such as greenhouse gasses.

Over the past few centuries, humans have released more greenhouse gasses, such as carbon dioxide, into the atmosphere, increasing the Earth’s temperature and contributing to climate change.

Researchers have shown that climate change poses a significant threat to human health, and believe that some of the negative ecological and human health effects of climate change are irreversible.

Scientists are concerned that tipping points, which may soon be crossed, cause “self-reinforcing feedbacks” in global heating, according to Prof. Will Steffen, a climate change expert and emeritus professor at the Australian National University in Canberra, Australia, and his co-authors. This would limit humanity’s ability to collectively respond to the climate crisis.

Toxic pollution, such as fine particulate matter, is also a major health issue.

According to the Environmental Protection Agency (EPA), fine particulate matter has been linked to many serious health problems, primarily respiratory and cardiovascular conditions. The EPA also notes that fine particulate matter can damage rivers, lakes, coastal waters, soil, and forests.

Researchers have shown that toxic and nontoxic pollution are not separate issues, as they can reinforce one another. However, some scientists have suggested that more research is needed to understand this relationship and to determine what the appropriate response to mitigate the health effects of toxic and nontoxic pollution should be.

Further, as the researchers behind the present study observe, there has been little research exploring the correlation between the location of toxic pollution exposure and the location of climate change vulnerability.

Determining this correlation could be important, as it may help the international community identify countries that could be most effectively supported to respond to both toxic and nontoxic pollution.

To determine the correlation between the location of toxic pollution exposure and climate vulnerability, the researchers of the present study analyzed data from three sources:

The data included 176 countries and covered the year 2018 — the most recent year all the datasets had information that included all the countries.

The researchers found a “strong correlation” between a country’s vulnerability to climate change and its population’s exposure to toxic pollution.

This finding confirms the researchers’ hypothesis and is backed up by previous research that has shown that the negative effects of climate change and exposure to toxic pollution disproportionately affect the world’s poorest countries.

Speaking to Medical News Today, Prof. Philip J. Landrigan, director of the Global Observatory on Pollution and Health at the Schiller Institute for Integrated Science and Society, Boston College, who was not involved in the research, said that fossil fuel combustion “is the major source of […] the greenhouse gas that [drives] climate change and [is also] responsible for 85% of airborne particulate pollution and for almost all pollution by oxides of sulphur and nitrogen.”

“Thus, it is logical that the health effects of both these two problems should fall disproportionately […] on the same populations.”

The researchers’ findings enabled them to determine which countries are most at risk of toxic pollution and climate change-related harm.

The researchers were also able to produce a top 10 “target list” to identify countries that are in the best position to protect themselves against the risks of toxic pollution and climate change with support from the international community. These countries are:

  • Singapore
  • Rwanda
  • China
  • India
  • Solomon Islands
  • Bhutan
  • Botswana
  • Georgia
  • South Korea
  • Thailand

The list also identifies which countries would not be able to respond to these risks even with international support. The researchers note this can be due to a number of factors, including an inability to enforce environmental standards, the exploitation of this by external businesses, and specific geographical issues.

As an example, the researchers highlight the Democratic Republic of Congo (DRC). The DRC is exposed to fine particulate matter from both the Sahara desert and from transport in urban areas. It also contains many national and international mining businesses that contribute to the pollution of its waterways and may be damaging people’s health.

Moreover, global heating and increased rain disrupt farming, which increases the risk of malnutrition and the prevalence of diseases.

For the researchers, rather than primarily supporting countries such as the DRC to mitigate the negative effects of toxic pollution and climate change, the international community needs to first help alleviate issues of structural inequality, poverty, corruption, and the exploitation of lax environmental standards. These issues make it more difficult to mount a direct response to toxic pollution and climate change.

The researchers found, however, that countries such as China and India, which are two of the countries in the top five highest target list, are not only vulnerable to climate change and toxic pollution but also well placed to respond to these issues with the support of the international community.

Speaking with MNT, Dr. Marcantonio said that the nature of toxic and nontoxic pollution from greenhouse gasses also affects the type of response that the international community should offer.

“The [t]arget list weights ‘readiness’ and interacts that value with the combined climate vulnerability and toxic pollution risk. So the countries on the bottom of the list tend to have low readiness and high vulnerability/toxic exposure.”

“One key difference between these variables is that toxic pollution and readiness are endogenous to each country on average, whereas several factors driving climate vulnerability are exogenous — [that is], the countries have no control over them, because they are driven by global ecosystem changes driven by the [greenhouse gas] emissions of all countries.”

“So, [reducing] toxic pollution tends to be more of a domestic/national policy program, whereas [reducing] many aspects of climate vulnerability require[s] international coordination, [such as the] Paris climate accords.”

“That said, there is no functional international agreement governing toxic pollution despite the fact that it is the single largest environmental hazard to human health today — though climate change may overtake it in the coming decades.”

Dr. Marcantonio said to MNT that at the heart of the issue are global inequalities in consumption and the production of pollution.

“Each context, even down to the community and city level, requires a uniquely tailored scheme to best mitigate and/or adapt to current and future conditions. But as a human community, as a general rule, we need to substantially reduce our consumption — the primary driver of toxic and nontoxic emissions — and redistribute consumption, as there are substantial gaps in current use.”

“I get that for many folks, that might seem an obvious answer, but it is not happening, and we’re not even measuring it well.”

“Historically, high income countries have had the highest per capita greenhouse gas emission rates and are the driving force behind much of the consumption of goods produced in low income countries that contribute to toxic pollution production — though some of the toxic pollution is from other processes, such as transport, etc., so [cannot] be wholly [attributed to] external consumption.”

“But the bottom line is that the people most responsible tend to be less exposed and at risk, mimicking many issues of inequality that exist today.”

Speaking to MNT, Dr. Marcantonio pointed out that the negative effects of climate change and pollution are not limited to low income countries. Nonetheless, due to the inequalities in both consumption and contribution to pollution, high income countries have a responsibility to respond to the issue.

“As [we have] seen with many recent extreme weather events, all countries [are] at risk of the effects of climate change, whether rich or poor, even though poor countries on average face greater risks.”

“That said, high income countries have an important role to play both, because they tend to be the most responsible for greenhouse gas emissions and have the highest per capita rates of material consumption. It is largely due to these behaviors that the risks we identify are at the levels they are.”

“Recognizing this inverse relationship between responsibility and risk is nothing new, but hopefully, the moral and ethical implications of it are at least made a little more apparent and salient by our work.”

This was also supported by Dr. Alexandra Schneider, head of the Research Group Environmental Risks and senior scientist at the Helmholtz Zentrum München in Munich, Germany, who was not involved in the current research.

Speaking to MNT, Dr. Schneider said, “[…] the finding, [in] my opinion, reflects the current status of inequalities we have within countries and between countries.”

“It is very unlikely that a country would have resilience to one environmental factor but not to another one, so […] countries with reduced resilience, of course, [are also] more at risk [of the effects of] climate change as well as [of] air pollution. So for me, the finding is not unexpected or totally new, but […] it is important to point it out and make people more aware of it.”