When it comes to health-threatening air pollution in New York, toxic boilers are public enemy number one. These boilers—which burn #4 and #6 heating oil in apartment buildings and other structures—are a menace to the health and well-being of our city. While they are only used by one percent of all New York buildings, they account for an astonishing 86 percent of the city’s airborne soot pollution.

To put it another way: This noxious heating oil produces 50 percent more air pollution than all of the cars and trucks in New York City, according to the Environmental Defense Fund. And the human toll is staggering. We know that the air pollution caused by dirty boilers and other sources is responsible for more than 3,000 deaths and approximately 6,000 emergency room visits for asthma in children and adults in New York each year, according to the New York City Department of Health and Mental Hygiene.

This is a citywide problem, but the roots of it might surprise you. New data evaluated by the Manhattan borough president’s  office shows that 63 percent of the boilers using #4 and #6 oil are located in buildings with one or more units of rent-regulated housing. And a breakdown of these buildings by zip codes reveals that the 12 most affected neighborhoods, the so-called Dirty Dozen, are in the Bronx and northern Manhattan. Our analysis shows that 10467—including Bedfor Park and Norwood in the Bronx—has the highest number of dirty boilers in rent-regulated buildings (252) of any New York zip code. It also ranks fifth in the city for individuals under the age of 5, a population that is particularly vulnerable to such pollution. Earlier this year, Mayor Bloomberg proposed a $37 million loan program to help building owners convert dirty boilers and end the use of #4 and #6 heating oil. But his program does not address the heart of the problem. The owners of rent-regulated buildings face unique financial challenges, and we must find a more reliable source of capital for them—while at the same time preventing the costs of building improvements from being passed on to tenants through Major Capital Improvement (MCI) rent increases.

Already, we are doing some of this work in the Bronx. Last year, the Bronx borough president’s office launched a pilot program, investing $500,000 to assist low-income buildings in the Bronx to convert from #4 and #6 heating oil to either clean-burning natural gas or #2 heating oil. Such a program could easily be expanded, and we recommend several ways to do so.

One source of funding could come from the Regional Greenhouse Gas Initiative (RGGI), a multi-million dollar state program dedicated to helping reduce greenhouse gas emissions. Another source of aid could be temporary assistance through the Industrial and Commercial Abatement Program (ICAP), which currently offers tax abatements to many city businesses.

Whatever path we choose, time is of the essence: The mayor’s program offers “financial hardship” loopholes that would allow these boilers to continue polluting the city for years, and New York needs to move faster. The city’s current timetables for replacing these boilers—2015 for #6 oil boilers and 2030 for #4 boilers—is much too slow.

At the end of the day, this is about saving lives, saving the environment and saving some of our most precious affordable housing stock. Now that we know the stakes, and a practical way to solve the problem, it’s time to act.

Ed. note: Ruben Diaz, Jr. and Scott Stringer are the borough presidents of the Bronx and Manhattan respectively.