(Reuters) - Air quality in wildfire-stricken Los Angeles improved on Thursday from hazardous peaks hit earlier this month, as tiny soot particles that can penetrate the lungs and brain dropped to moderate levels, according to the Environmental Protection Agency's latest data.

Wildfire ash carries many carcinogens that could cause short- and long-term health problems, including asthma attacks and difficulty breathing.

Calculating air pollution from wildfires and other events has become more complicated. That doesn’t mean it’s necessarily more accurate.