Investigations

The American Lung Association ranks Bakersfield, Calif., as the most polluted city in the nation for average annual levels of dangerously high particle pollution. The city is second for short-term pollution spikes, a ranking Bakersfield has held in eight out of the last 10 reports.

State regulators for more than a decade allowed a New Mexico refinery to delay fixing leaky equipment that was releasing toxic gases, including high levels of the carcinogen benzene.

“Plastic Wars” looks at how the plastics industry has used recycling to help sell more plastic — and why the plastic waste problem has only grown.

Public filings outline troubling relationships between energy company, local legislators and special interest groups in Ohio.

In Philadelphia, an air monitor on the border of the East Coast’s largest oil refinery recorded a level of cancer-causing gas more than 21 times the federal limit.

They experienced the war in Afghanistan on the ground. Here’s what they had to say.

As of 2018, the U.S. opioid epidemic has claimed more than 400,000 lives. Yet the faces of some victims remain hidden.

How opioid addiction starts: Five people describe the moments that led them down a trail of dependency.

New details about the marketing campaigns used to persuade the medical community that addiction was rare and patients were suffering needlessly.

Scholars and experts are frequently called before Congress to testify, and sometimes do so without disclosing potential financial conflicts. A lack of accountability helps witnesses not disclose foreign funding as required, whether intentionally or not.