Kentucky wildfires destroy trees, homes and habitats, and endanger the lives of people and animals.

The majority of them are preventable.

“About 98 or 99 percent of wildfires are human-caused,” said Mike Harp, a forester and fire management coordinator at the Kentucky Division of Forestry.

Arson accounts for about 65 percent of the fires, and the open burning of trash, debris and brush accounts for about 30 percent of fires. Power line malfunctions, mechanical failures, lightning and other causes constitute a small portion of wildfires, Harp said.

Kentucky’s wildfire threat is relatively low compared to the West, but wildfires still impact the region.

“People don’t realize that in Kentucky we’re still averaging over 1,000 wild land fires each year,” Harp said, ranging from 10 acres to occasionally 1,000-plus acres.

With Monday’s official start of the fall forest fire hazard season, which extends through mid-December, state officials are preaching caution about outdoor burning.

In the fall, sunlight penetrates through the newly bare trees and dries leaves on the forest floor – and leaves are a major culprit in the spread of wildfire.

“Leaves are what burn in Kentucky,” Harp said.

State law restricts open burning within 150 feet of any woodland or brushland. The law also limits burning to between 6 p.m. and 6 a.m. That’s because after 6 p.m., the sun goes down, the wind lessens and relative humidity increases.

“There’s a considerably less chance of the fire getting away or spreading,” Harp said, and “first responders can catch fires earlier.”

State law also prohibits the burning of household trash other than uncoated paper products. Aerosol cans, plastic, tires, food waste, coated wire, motor oil, painted or treated lumber and many other materials create toxic fumes and ash.

“Toxins created from burning plastics mixed with food scraps and all the other things found in garbage creates all kind of chemicals that are dangerous for human health and the environment,” said John Mura, executive director of the office of communication at the Kentucky Energy and Environment Cabinet.

Yet many people still choose to burn their trash.

“People are not aware of what they can and cannot burn outside,” said Roberta Burnes, a policy analyst for the Kentucky Division for Air Quality.

Consequently, the division receives about 700 complaints each year about open burning. Division leaders investigate all claims and typically discover that the fire source is illegal about half the time, according to Burnes.

The people reporting the incidents – which don’t always turn out to be wild land fires – are “generally the citizens concerned about their health,” Burnes said.

That’s for good reason. Air pollution from open burning can cause serious health problems.

Wildfires affect air quality by emitting substantial amounts of volatile and semi-volatile organic materials and nitrogen oxides that form ozone and organic particulate matter, according to a recent report from the National Oceanic and Atmospheric Administration.

Microscopic particles can enter the lungs and cause burning eyes, a running nose and aggravated chronic heart and lung diseases. Particle pollution exposure has even been linked to premature death.

Individuals affected the most by wildfires include people with heart or lung disease, elderly people, children, pregnant women and people with diabetes.

Animals and natural habitat are also affected.

Wildfires harm the environment by releasing carbon dioxide, black carbon, brown carbon and ozone precursors into the atmosphere – which affects radiation, clouds and the climate, according to the NOAA report.

As the nation experiences warmer and drier climates, especially in the West, experts predict more frequent and intense fires near or within populated areas, the report says.

At Mammoth Cave National Park, there have been very few fires, which generally haven’t exceeded 200 square feet, according to spokeswoman Molly Schroer. “We’re very fortunate in this area because of the rainfall and climate,” Schroer said.

But the park has a wildfire fire engine and trained staff ready to respond to fires.

For the rest of the state, officials seem optimistic in their efforts to safeguard forests and change the culture of preventable fires.

“There has been a downward trend in the number of fires that we are responding to,” Harp said, especially in the past four years.

He said it’s difficult to pinpoint the reasons why, but thinks the increase in trash services and subsequent decrease in trash burning could play a role.

Arson can be reported to the Division of Forestry through the arson hotline, 1-800-272-7766.