Five U.S. states have passed laws regulating the intentional release of balloons amid growing concerns over the risk they pose to wildlife. Illinois could be one of the next states to take action.

New rules for a scrap metal yard on the city’s North Side require the facility to reduce emissions of potentially cancer-causing compounds after it violated federal air pollution standards last summer.

Living in areas with poor air quality increases one’s likelihood of suffering from depression, bipolar disorder and other mental illnesses, according to a new study by University of Chicago researchers.

Using satellite images and data on wildlife activity, scientists determined that artificial light levels found in more than a third of the city are altering the circadian rhythm and behaviors of animals throughout the city.

A steel company apologized for a spill of cyanide and ammonia that led to a fish kill and prompted the closure of beaches along Lake Michigan, saying it “accepts responsibility for the incident.”

As urban agriculture programs expand in Chicago and other cities, a new project aims to unearth data on one of the biggest potential obstacles to city-based farming efforts: soil contamination.

What lies below the surface of the Chicago River today is not what it was a century ago, but pollution is still a problem. A Chicago nonprofit aims to offer real-time water quality data to the public later this year.

A lawsuit filed Friday aims to stop a plan by the National Highway Traffic Safety Administration that would lower fines for automakers that fail to meet fuel-economy standards. 

A new law in Illinois prohibits discharge of coal ash into the environment and establishes a regulatory framework to ensure that polluting companies finance the cleanup of coal ash waste, according to the Illinois Environmental Council.

Gov. J.B. Pritzker and four of his counterparts in the region are urging candidates in the 2020 presidential election to back a new plan aimed at protecting the Great Lakes.

Tens of billions of gallons of untreated sewage and stormwater runoff end up in the Great Lakes each year, polluting the water and prompting beach closings and swimming advisories. How new legislation aims to help.

Rising temperatures this week could lead to unhealthy air quality, particularly for people with respiratory conditions, as the heat combines with pollution from vehicle emissions and other sources, says the American Lung Association. 

A bold plan to get hundreds of people into the Chicago River for a 2.4-mile swim remains docked for a year or so after organizers struggled to secure permits and coordinate with a number of city agencies.

The Environmental Protection Agency will soon begin removing up to 2 feet of contaminated soil from as many as 15 homes near a storage facility operated by S.H. Bell, which handles manganese and other industrial materials. 

Responding to increasing public concern over environmental health threats, researchers have published a guide designed to help residents of Great Lakes communities determine if air, water or soil contamination is affecting their health. 

Public officials and environmental advocates are speaking out against the Trump administration’s rollback of an Obama-era effort to shift the U.S. away from coal-fired power plants.