Air Quality Plans Focused on Tailpipes May Be Missing Summer Pollution Sources
Tailpipes have long been the prime suspect for dirty city air. Over a summer month in one New York suburb, though, chemical products used in homes and businesses, from perfume and lotion to cleaning spray and paint, put more air-polluting gas into the sky than traffic did. Added up, those products accounted for about 40% of the area’s summer emissions of gases called volatile organic compounds, compared with 31% from traffic, according to a new study in Science Advances.
Winter reversed the ranking. When temperatures fell, those products gave off far less gas, and traffic, whose output held steadier year-round, took the top spot. Heat was the deciding factor: warm weather makes products evaporate faster and pushes plants and homes to release more.
That matters because these gases react with sunlight and other chemicals in the air to form ozone, a main ingredient of smog, and fine particles, both linked to breathing and heart problems. A federal database that estimates pollution from each source missed the seasonal swing, overestimating winter emissions by about 2.5 times.
Tower Readings Show Summer Air Pollution Gases Roughly Doubled
Estimating pollution from air samples can mislead, because wind and chemical reactions shuffle gases around after release. Here, daily rises and falls in how much of a gas hung in the air did not track how much was being released.
A team from Colorado State University, the University of Minnesota and other institutions instead measured what was actually rising off a neighborhood. They mounted instruments on a cell tower in Mineola, New York, about 17 miles from New York City, where homes, restaurants and a major highway fill a densely populated suburb. Sensors about 107 and 197 feet up tracked which gases were rising and which were being absorbed. Readings ran for about a month in summer 2023 and 20 days in winter 2024.
Summer emissions came out to more than double winter levels, and their total potential to form ozone and particles rose even more sharply. The tower picked up 126 different gases in summer but only 50 in winter. Ethanol, which comes from traffic, cooking and chemical products, led the list in both seasons, making up 22% of summer emissions and 28% of winter emissions.
Everyday Products Edged Out Traffic in Summer Air Pollution
To pin each gas on a source, the team sorted the readings by chemical makeup, time of day and wind direction. Five groups emerged. Chemical products, the top group when counted together, came from personal care products, cleaning products and paints spread across the area, plus specific businesses such as auto repair shops and lawn care operations. Traffic, the runner-up, showed rush-hour peaks around 8 a.m. and 5 p.m. and roughly half as much output on weekends, a sign that nearby roads serve largely as commuter routes.
Plants and homes added 23%. That group included chemical traces from building materials, such as wood, that break down faster in hot attics. Restaurant cooking made up 6% in summer, with its peaks centered on a cluster of restaurants north-northwest of the tower.
Several clues point to heat. Emissions from the spread-out chemical products climbed as temperatures rose, and the link was stronger over pavement and rooftops than over lawns and trees. Other cities point the same way. A separate study in Beijing found chemical products outranking vehicles, at about half of measured gas emissions versus 24%. An earlier study in Los Angeles found heat-sensitive emissions, mostly from plants, accounted for about 60% of the summer ozone and particle pollution those gases can form.
Source : https://studyfinds.com/everyday-products-summer-air-pollution/