A call for stricter air pollution standards

{***Noah***}

Coming up on Harvard Chan: This Week in Health…

A new call for stricter air pollution standards in the United States.

{***Francesca Dominici Soundbite***}

(Let’s say for a moment that you have FBI intelligence that tells you there’s going to be a jumbo crash every 12 days…would you intervene?)

In this week’s episode: We’ll tell you about new research strengthening the link between air pollution and negative health effects—and why scientists say the U.S. needs to do more to keep the air clean.

{***Pause/Music***}

{***Noah***}

Hello and welcome to Harvard Chan: This Week in Health…It’s Thursday, June 29, 2017. I’m Noah Leavitt.

{***Amie***}

And I’m Amie Montemurro.

{***Noah***}

This week you’ll be hearing from two Harvard Chan researchers who are issuing a new call for the U.S. to strengthen its air pollution standards.

{***Francesca Dominici and Qian Di Soundbite***}

(My name is Francesca Dominici. I’m a professor of biostatistics at the Harvard T. H. Chan School of Public Health and the co-director of the Harvard Data Science Initiative.

Hi, I’m Qian Di, I’m a fourth year doctor student from the EH department, environmental health.)

{***Noah***}

Francesca Dominici and Qian Di authored a comprehensive new study which strengthens the link between air pollution and premature death.

{***Amie****}

It’s research of an unprecedented scale—covering 60 million Americans—or 97% of people older than 65.

Dominici and Di compared pollution data with health records from Medicare to analyze the effects of two kinds of pollution—fine particulate matter and ozone.

{***Francesca Dominici Soundbite***}

(We linked claims data with air pollution data, and we found that long-term exposure to air pollution, in particular fine particulate matter and ozone, are harmful to human health, and specifically are increasing the risk of death even when our American citizens breathe pollution level below standards set by the Environmental Protection Agency.)

{***Amie***}

As Dominici mentioned—the negative health effects of air pollution are significant even below current EPA levels—called the National Ambient Air Quality Standards.

{***Noah***}

According to their research, Dominici and Di say that lowering the level of fine particulate matter in the atmosphere by just one microgram per cubic meter could save about 12-thousand lives every year—according to Dominici that’s the equivalent of a jumbo jet crashing every 12 days.

{***Amie***}

And there are also similar benefits when it comes to reducing ozone.

Lowering the level of ozone by just one part per billion would save about 1,900 lives, according to researchers.

{***Noah***}

While the EPA sets long-term limits for fine particulate matter air pollution, there are no such standards for ozone.

Under the Clean Air Act the EPA is required to review all scientific evidence on air pollution levels and human health—and the agency is required to lower limits if current levels are shown to be harmful to human health.

{***Amie***}

Dominici says this research makes a strong case that long-term ozone limits should be established—and that limits for fine particular matter should be lowered.

{***Francesca Dominici Soundbite***}

(For fine particulate matter, the Environmental Protection Agency has a National Ambient Air Quality Standard for long-term exposure, which is set at 12 micrograms per cubic meter. And this study, because of an enormous power, we were able to estimate very precisely whether long-term exposure to fine particulate matter below 12 micrograms per cubic meter increased the risk of death. And so that is very strong evidence that they need to lower the standard even further.)

{***Amie***}

And you heard Dominici mention just how comprehensive this study was.

And it goes beyond the data from 60 million Americans we mentioned earlier.

{***Noah***}

Thanks to the analytical and computational skills of Qian Di, the research team was able to fill in gaps in previous air pollution studies.

The information on levels of air pollution comes from EPA monitoring stations around the U.S.

But those monitoring stations can’t cover large areas where people live—especially in rural parts of the United States.

{***Amie***}

To address this, Di worked with Joel Schwartz, professor of environmental epidemiology at the Harvard Chan School, to leverage satellite data on air pollution.

They used these measurements along with a computer simulation of air pollution to measure the effects of air pollution across the country regardless of where people live.

{***Qian Di Soundbite***}

(What we were doing is to use satellite data, to use some computer simulation data to predict air pollution levels for people living far away from EPA monitoring sites. And we also found a significant health effect for them.)

{***Amie***}

And this work required a huge amount of data and computational analysis, Di told us.

{***Noah***}

It required many high-powered computers here at Harvard—and Di could only run his models during Christmas when the processing demand for the computers would be the lowest.

{***Qian Di Soundbite***}

(So the whole process is really computationally intensive. We need to deal with six million people, followed up to 30 years. And the whole process, we leverage the supercomputer provided by Harvard at an average of hundreds of CPU to run the analysis at the same time, if added up together, the total CPU time is almost two years.)

{***Noah***}

Qian Di’s work helped shed important light on the effects of air pollution—but he and Dominici still have many questions.

{***Amie***}

They found that men, blacks and low-income Americans were at the greatest risk from fine particulate matter exposure.

And blacks in particular have a mortality risk three times higher than the national average.

What’s not clear is why these groups are more at risk.

{***Noah***}

Dominici says more research is needed to unpack the exact mechanism, but she says there are likely socio-economic factors at play.

For example, low-income groups may have less access to health care, making them more susceptible to the negative effects of air pollution.

{***Amie***}

Dominici and Di told us that clean air should be considered a fundamental right—because it’s something that’s out of our control.

And they add that there’s a growing awareness that addressing air pollution is a social equity issue—because it is affecting those who are most vulnerable.

{***Noah***}

Dominici says this is a key point to understand amid the politicized debate over climate change in the U.S.—and President Trump’s decision to pull out of the Paris Climate Agreement.

She points out that the same causes of greenhouse gas emissions—such as cars and fossil fuel burning power plants—are the same sources of fine particulate matter air pollution.

So by taking steps to mitigate climate change—we’re likely to see positive effects when it comes to air pollution—and vice versa.

{***Amie***}

Dominici says that rather than arguing over climate change, the U.S. should be working to strengthen the EPA and invest in alternative energy—because the health benefits are likely to be significant.

{***Francesca Dominici Soundbite***}

(And so when we are talking about losing jobs in the coal industry and trying to dismantle a lot of the progress that we have been making to clean the air and continue to make progress, it’s not only reversing the progress on climate change, but really– and with the power of the study– meaning really not intervening on protecting and saving life for our people right now. Let’s say for a moment that you have FBI intelligence that tells you that there’s going to be a jumbo crash every 12 days. Would you intervene? Or you will say, oh, maybe we need to think about the coal industry. Of course you will intervene.)

{***Amie***}

The research from Dominici and Di is not the first to show the negative health effects of air pollution—but they do believe it will have long-term significance for researchers.

{***Noah***}

That’s because all of the data is publically available government information—which means that it will be easier for other researchers to reproduce their work and validate the findings.

{***Amie***}

That’s all for this week’s episode.

Just a quick programming note that we’ll be taking next week off, but will return on July 13 with a new episode.

{***Noah***}

Coming up in that episode: Why you should swap out saturated fats for unsaturated fats.

We’ll speak to the author of a new American Heart Association advisory about why unsaturated fats are your best choice for heart health.

{***Amie***}

In the meantime, you can always listen to this podcast on iTunes,Stitcher, or Soundcloud.