Railroad ties in Canada and the U.S. are treated with coal tar creosote, which the United States Environmental Protection Agency and Canada Health have jointly investigated for health risks. Studies on contact through touch, soil and water show cancers and other dangers from contamination at sites where creosote was used to treat railroad ties.
Calling creosote a possible human carcinogen in 2007, the EPA has a list of warnings about its use. These cautions apply to railroad ties decommissioned by the railroads and reused by humans for landscaping, playgrounds, gardens and on farms.
Danger to Bare Skin
Studies show skin exposure to creosote-treated products like railroad ties can cause skin blistering or peeling. The EPA states humans should not use creosote treated railroad ties where frequent or prolonged contact with bare skin can occur. This includes residential settings, where the agency has not approved any uses for creosote or railroad ties.
While railroad ties have weathered by the time they are retired by the railroads, it is recommended to wear long sleeves, pants and gloves when handling them and washing these separately from other clothing.
The agency specifically warns against using creosote treated wood for cutting boards. Long-term, direct skin exposure to the coal tar creosote in railroad ties, as with all forms of creosote, has been linked to cancer of the skin and scrotum. The EPA also warns against using creosote treated railroad ties in farm buildings where livestock could come in contact with them.
Danger of Inhaling
The EPA cautions against burning old railroad ties. Burning can release toxins in the air, which can be dangerous to respiratory health. The agency also advises avoiding inhaling sawdust from creosote treated wood.
Every year, 825 million pounds of coal tar creosote are used as a wood preservative in the U.S. for the majority for railroad ties. Polycyclic aromatic hydrocarbons (PAHs) are among 300 chemicals in creosote. PAHs are the same carcinogens contained in cigarette smoke, a known carcinogen. The EPA warns against inhaling creosote vapors, which can be released by heat. The vapors of creosote tars can build up, as in chimneys. Railroad ties should never be burned in fireplaces.
Water Contamination Dangers
Railroad ties can leach creosote into soil and water systems. Eating food or drinking water with high levels of creosote may cause burning in the mouth and throat, stomach pains, severe skin irritation, convulsions, and kidney and liver problems in humans.
Health Canada found severe contamination of groundwater at several creosote-contaminated sites. Specifically, benthic organisms and the general health of the aquatic ecosystem near a major wood-treatment facility in Thunder Bay, Ontario, were found to be adversely affected by the presence of waste creosote pooling on the sediments.