South Bronx residents did not exactly need a spreadsheet to know the air can feel heavy, but a new community-backed analysis now has the numbers to prove it. During the first year of New York City’s congestion-pricing tolls, fine particulate pollution across the South Bronx ticked up slightly, with small but measurable increases at most neighborhood sensors.
Across 19 monitors, the project’s authors report an average rise of about 0.22 micrograms per cubic meter in PM2.5. A handful of devices right next to major expressways saw much sharper jumps, including one site that recorded an increase of about 1.29 micrograms per cubic meter. The findings land just as city officials roll out a $20 million mitigation package focused on childhood asthma, and as local groups move to expand monitoring and distribute air purifiers.
What the monitors recorded
According to Streetsblog, researchers working with South Bronx Unite and Columbia University compared readings from 19 sensors placed around Port Morris and Mott Haven before and after congestion-pricing tolls went into effect. They found that 17 of the monitors showed post-toll increases in PM2.5.
Across all sites, the average rise came in at roughly 0.22 micrograms per cubic meter. Four monitors positioned near major expressways logged the largest spikes, including one that registered an increase of about 1.29 micrograms per cubic meter, suggesting that traffic-heavy corridors are bearing the brunt of the change.
Community reaction and mitigation plans
Local advocates say the pattern fits what they have been warning about: drivers rerouting around the toll zone and funneling more traffic through already overburdened South Bronx streets. They are now pushing for a real community seat at the table as mitigation dollars start to move.
Mychal Johnson, a South Bronx Unite board member, told News 12 The Bronx that he wants residents to help decide how the funds are spent. Environmental-justice educator Jada Tulloch, also with South Bronx Unite, has said the group will keep partnering with Columbia and will distribute air purifiers through an American Lung Association partnership while adding about 50 more monitors to the local network.
City and MTA response
On World Asthma Day, Mayor Zohran Mamdani announced a $20 million investment drawn from the MTA’s congestion-pricing mitigation program to expand Bronx asthma services and in-school case management, according to a city press release. Officials describe the money as part of a broader mitigation fund the MTA has pledged for neighborhoods that face disproportionate pollution burdens.
The agency’s first evaluation of the tolling program also reported an 11 percent drop in vehicle entries into the tolled Manhattan zone in its first year, even as travel volumes and routing patterns shifted across other corridors.
Why small changes still matter
Public-health researchers note that even modest upticks in PM2.5 can matter a lot in places that already live with heavy pollution. A review of epidemiological evidence has found that a 10 micrograms-per-cubic-meter increase in PM2.5 is associated with roughly a 2 percent rise in respiratory admissions. That relationship means smaller fractional increases still add measurable risk, particularly for children and people with asthma in the South Bronx.
Advocates say that points to the need for a layered response: more green space, better building-level filtration and targeted upgrades to truck fleets, alongside continued community monitoring to track what is happening at the block-by-block level.
What to watch next
The South Bronx monitoring project is now expanding its network and continuing analysis, while the city says mitigation dollars will begin flowing into expanded asthma services and related interventions. At the same time, the Department of Health and the MTA have indicated that additional borough-level air-quality analyses are on the way.
Residents and advocates are already signaling they intend to press for local input as those official reports land and as final mitigation plans take shape.
