Carolyn Konheim, whose sons’ soot-specked white snow suits transformed her from a high school history teacher into a crusading New York environmentalist who targeted water and air pollutants, congested streets and other scourges of modern urban life, died on Nov. 25 at her home in Brooklyn. She was 81 .

The cause was complications of Parkinson’s disease and dementia, her husband, Brian Ketcham, said.

The couple were partners in Konheim & Ketcham, a consulting firm that prepared environmental impact statements and conducted pollution-abatement surveys for governments and private clients from 1981 to 2007.

They also volunteered their expertise to civic groups concerned about the effects of development in their neighborhoods, operating through a nonprofit group, Community Consulting Services, from 1993 to 2012.

In the mid-1960s, after she grew concerned by the dark flakes of ash raining onto her sons’ winter wear during their walks in Riverside Park in Manhattan, Ms. Konheim joined the nascent green movement, which had been galvanized largely by Rachel Carson’s seminal book on environmental threats, “Silent Spring,” published in 1962.