Earlier this week, two vans loaded with precision instruments drove along the streets of New York and New Jersey in hot weather, sniffing the air for toxic chemicals.
They detected spikes in methane, a potent greenhouse gas, likely caused by leaks or buses burning natural gas. They found plumes of nitrous oxide, possibly coming from wastewater. Throughout the ride, they recorded elevated levels of ozone, the main component of smog, as well as cancer-causing formaldehyde — both of which can easily form in hot weather.
Bottom line: The streets are dotted with pollution hotspots. High temperatures make pollution worse.
“If you want a chemical reaction to go faster, you need to add heat,” said Peter DeCarlo, an atmospheric air pollution researcher at Johns Hopkins University who is leading a study using trucks to measure Louisiana’s petrochemical corridor. Projects on emissions along the route. “On hotter days, it’s the same idea,” he said.
When temperatures rise, air pollution surges, exacerbating the dangers of global warming. That’s one reason air pollution alerts have been issued this week for cities and counties hit by a heat wave in the eastern United States.
Over the past three days, New York City has warned that ozone levels in the city are “unhealthy for sensitive groups.” Detroit and Chicago also issued air quality alerts this week. Drivers in Ohio, Michigan, Kentucky and Indiana are urged to avoid filling up before 8 p.m. and try to share rides or avoid driving to reduce emissions.
The bad air has something to do with atmospheric chemistry, said Professor DeCarlo, whose van, accompanied by two New York Times reporters, drove through the South Bronx, East Harlem and downtown. Pollution from burning fossil fuels reacts with heat and sunlight to form ground-level ozone. Higher temperatures speed up this process.
Formaldehyde emissions can come from a variety of sources, including wildfires and household products, and also increase as temperatures rise. “Chemicals that produce high concentrations of ozone can also produce additional harmful air pollutants, such as formaldehyde,” Professor DeCarlo said.
Local hot spots can sometimes be seen. In some Manhattan neighborhoods, for example, formaldehyde levels are twice as high as in surrounding areas, likely due to particularly dirty burning caused by malfunctioning equipment nearby.
The relationship between thermal pollution is of increasing concern around the world. Health hazards from extreme heat aren’t the only consequences of record-breaking temperatures. The World Meteorological Organization said in a report last year that as temperatures rise, so will air pollution.
“Climate change and air quality cannot be treated separately,” WMO Secretary-General Petteri Taalas said at the time. “They go hand in hand and must be addressed together to break this vicious cycle.”
Inhaling high levels of formaldehyde and ozone has been linked to problems such as respiratory tract irritation and inflammation, reduced lung function, and difficulty preventing and controlling asthma attacks. Keeve Nachman, an environmental health and risk assessment researcher at Johns Hopkins University and co-lead of the mobile monitoring effort, said air exposure is particularly harmful for people with lung diseases such as asthma or chronic bronchitis. People worry.
Coincidentally, as New York was hit by a heat wave this week, the team had pollution-sniffing vehicles in the city to demonstrate their technology.
Professor Nachman said that although formaldehyde is carcinogenic to humans, cancer mainly comes from long-term exposure to formaldehyde, rather than a temporary increase.
He said it’s also important to realize that chemical exposure doesn’t just happen one at a time, but that we are often exposed to multiple chemicals that can work together to harm our health. “Hot weather causes people to breathe in multiple harmful chemicals at the same time,” Professor Nachman said. “Formaldehyde and ozone are perfect examples.”
One of the trucks will return to Louisiana later this year to measure up to 45 pollutants in the state’s petrochemical industry as part of a grant from Bloomberg Philanthropies’ Beyond Petrochemicals campaign. In a preliminary peer-reviewed study published this month, researchers found that emissions of ethylene oxide, a cancer-causing gas used in plastic production, are much higher than previously known.
The van the researchers drove is a high-tech wheeled laboratory built by environmental measurement technology company Aerodyne that can instantly see pollution levels and even track plumes to determine their source. “It’s a bit like a video game,” Professor DeCarlo said. “And we’re able to measure everything at the same time.”
Blakey Migliozzi Contributed reporting.
