‘Black rain’ in Iran and the environmental cost of war

catty. Every show brings you quick, actionable advice you can put to use in your garden

or landscape. From the heartland to your home garden, learn from those who grow it best. Listen to garden variety of podcasts from Iowa Public Radio and the NPR network. You're listening to shortwave from NPR. The US and Israel launched military strikes on Iran late last month, and those strikes have continued. Among the targets this month were oil refineries and depots in and around the capital city of Tehran. And that released thick plumes of black

sweat and smoke that drifted across the city. Some Iranians said it burned their eyes and throat, and that it was painful to breathe. And then came the black rain, which Tehran residents said left behind a dark oily residue.

“That's what they told the BBC. Black rain is a phenomenon caused by large amounts of chemical”

pollutants in the air. That's according to Peter Ross, a toxicologist, and senior scientist at Rain Coast Conservation Foundation in Sydney, British Columbia in Canada. We're seeing a soup of chemicals including the sulfur oxides, the national oxides that form acid rain. We're seeing metals. We're seeing other carcinogens and volatile chemicals that can cause dizziness death and/or contribute to cancer. And after the rainfall, Iran's government urged residents to stay indoors. The World Health

Organization backed them up. They warned Iranians of the potential health risks associated with breathing in these high levels of toxic pollutants. The black rain and the the acidic rain coming with it is indeed a danger for the population. Alija Farian, Iran's Deputy Health Minister told Al Jazeera that this rain is already contaminating the soil and water supply, which could indicate longer-term consequences for public health as well as the local environment.

So today on the show, Iran's black rain. What we know about the chemicals contained in it, the potential effect of those pollutants, both short and long-term, and what it all says about the environmental cost of war. I'm Emily Quang and you're listening to shortwave, the science podcast from NPR. Okay, shortwaveers. I'm here with Peter Ross, a toxicologist, to talk about black rain. And Peter,

I want to just back up a little, when a strike hits an oil storage facility as has happened in

“Iran. What happens then, chemically in the air? Well, I think what we're talking about is explosion.”

These are, of course, fossil fuels. There are volatile gases that are explosive in that mixture. There are liquid fuels that will also combust so we get fire. And as a result of the explosion and the ensuing fire, we're going to see a lot of different pollutants,

basically injected to the atmosphere and distributed through the neighborhoods.

What else is in this chemical soup? We think what are their kinds of chemicals? And can you go into more specifics as to what damage they may cause, specifically to the body? Well, I'd be concerned about the health of people in the short term. So I'd be worried about airways. I'd be worried about people that have asthma or COPD or other lung ailments.

“So when we would have a forest fire or a major fire, we would see an increase in emergency room”

visits. We would see an increase in asthma attacks. And we would also increase seeing increases in mortality. So we can expect all of these things to be happening in T-Round right now. But in this book, in addition to the sulfur oxides, nitrogen oxides, carbon monoxide, the polycyclic aromatic hydrocarbons or pHs, we would also see a benzene, tallewing and a number of other explosive gases that are very toxic. If we inhale them, these can cause

dizziness. They can cause people to faint. They can cause outright mortality. So we're going to see acute threats to public health. That will be in the short term or the immediate term. And as the fires subside, we're going to start to see longer, longer term risks to public health water quality and habitat for wildlife. Yeah, I want to talk about more about the long-term

impacts on wildlife in a minute. I'm going to get a little atmospheric scientist for a second,

because most people, when they think of rain, they think of it as a cleansing phenomenon. That's not happening here. What's happening is as these explosions are happening, it's sending up chemicals, pollutants into the atmosphere, which are then mixing with water and oxygen

or is it falling to the ground all on its own? We're seeing pollutants trapped in the atmosphere,

“we're seeing pollutants that are scavenged by water vapor forming droplets and coming down in rain.”

So yes, rainfall is a cleansing phenomenon that occurs in the atmosphere. But unfortunately for what's on land in terms of crops in terms of waterways, this will actually disperse the pollutants across crop lands into streams, rivers, creeks, lakes, potentially downed to ground water. So in the long-term, what we're talking about is really a distillation phenomenon whereby

we see the pollutants moving from the air to the land into waterways, where they basically

create a long-term risk for public health. Given that the potential for pollution to see been to groundwater, what could be the long-term impact there? Well for drinking water supplies, we tend to rely on either surface water or groundwater. So groundwater to think of a spring, think of a well. It's basically a natural reservoir. It is a little bit filtered out or cleaned out in terms of, you know, with the soils over top. But it's very vulnerable as well. So if we

contaminate groundwater with chemicals of concern, and that would include some of the other compounds found in the black rain, then we're in it for the long haul. We're going to be relying on water that is degraded and potentially severely threatening as a drinking water source for humans. Beyond that, the potential harm for human health could also be worsened by terrons topography. I mean, I'm thinking about how the city lies at the base of the Alborth mountains,

these beautiful mountains that can also block air circulation. Like, what do you think about the effect of topography on all of this? Well, I haven't seen any data from this, but we can

very well expect that in such a semi-inclosed basin, as you describe it, with 10 million inhabitants.

We've got smoke that is lingering at different altitudes, different levels. We've got toxic gases that are basically permeating all the streets in all the ways. So not really a pleasant urban environment to live in. So with 10 million people living in these areas, we'd be worried about such measures as PM2.5. These are very small particles of, basically, invisible to the human eye. When we breathe in, they can actually go right through the lungs into circulation. They can cause

cardiac arrest. They can lead to cancer, lead to all sorts of ailments. So what we can expect right now is that alarm bells would be going off in terms of those that are worried about

“air quality in human health. Yeah, I got to say, I think for people in the U.S., it's hard to picture”

this level of pollution. Maybe for some folks, the closest comparison might be wildfire smoke. How does this compare to something like wildfire smoke? Well, I think a local citizens have reported apocalyptic sort of smoke and visuals in Tehran, not surprisingly, and certainly from the short-term perspective, people would be looking to manage their health and limit their exposure these things by wearing masks, which will help to keep out some of the dust and sweat and the

fine particles staying indoors. But in these sorts of environments or climates, it's very difficult to keep outdoor air out a lot of the homes of circulation that opens up to the outside and

and can render people exposed indoors to this basically same thing that's happening outdoors.

I mean, is it realistic for people to be even able to stay indoors when perhaps some people are also trying to avoid strikes, right? So their homes may not be entirely safe in some places.

“Well, I think in any conflict area, you're always worried about your immediate physical safety”

first of foremost air quality and water quality tend to come a little bit that line. Right, you're just trying to stay alive. You're trying to stay alive, absolutely. But part of staying alive is being able to breathe and drink water. Without water, we are deceased within three to four days. So I'm very concerned about the acute short-term risk to people, pets, agricultural animals, wildlife, but I'm also concerned about water quality,

drinking water that in the medium to long-term may be catastrophically threatened. Yeah. What would recovery look like for the environment and the health of millions of people in Tehran? I think as a scientist, I grew up thinking that mother nature was tolerant and could rebound readily. But in the case of petroleum accidents and incidents, we've really learned

that was 1989. So we're not talking 35 plus years ago. We can still find unweathered

“commercial oil from from the tanker that ran a ground under rocks and boulders. Thousands of”

sea otters were killed outright, hearing and salmon stalks were impacted for years. It takes years if not decades to recover from the short-term, the acute effects. But we're still saying lingering

risks associated with that oil spill from 1989. And back in Paris in Exxon,

Valdez was one oil tanker. This is multiple. Now we have several tankers on fire. We've got

“oil depose on fire. We've got refineries on fire. We've got multiple sources of this complex”

mixture of pollutants that are going to be discharged into the air and impacted through this black rain phenomenon. This isn't happening just in Iran. There have been strikes on oil infrastructure in other parts of the Middle East due to this war and making oil infrastructure a part of war not only is inherently dangerous, but what I'm hearing from you is it's very bad for the long-term health of the people and the environment. And it really begs the question about

“the environmental impact of war. In a way that I don't remember that being as much of a discussion”

we had as a society like during the wars in Iraq and Afghanistan. Is there a consciousness shift here? Are people asking new questions of war? I think there's more immediate awareness because of media, social media, the internet. Those visuals are dramatic from Tehran as well as the neighboring states of Iran. We know that these pollutants know no borders. I think in this case we've seen a rather unprecedented attack on oil facilities. As a toxicologist, I can only say that I find

that regrettable. It's really a crime against the environment and many innocent bystanders

are going to be impacted or threatened by poor water quality, poor air quality and basically toxic

crops to consume at the market. Toxicologist Peter Ross, thank you so much for talking to us. Thanks, Emily. If you like this episode, please share it with a friend. It really helps our show out. This episode was produced by Rachel Carlson and edited by Beatle. A Runeir and Angela Zhang checked the facts. Robert Rodriguez was the audio engineer. I'm Emily Quang, thank you for listening to shortwave from NPR.