It's no secret that energy production and use can pose a significant threat to human health. But how much?

A report from the National Research Council, released Monday, put the number at $120 billion in the United States in 2005, the most recent year when comprehensive data was available.

In the report, "Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use," the research council set out to quantify what it said are costs that aren't shown in market pricing for harvest energy sources such as coal and oil, producing electricity and fuels from them, and transporting them to gas stations and other retail outfits.

Knowing these hidden costs, called "external effects" by economists, would help consumers and businesses understand the impact of their energy consumption and provide context for creating government policies. Congress asked the research council to write the report back in 2005. These hidden costs also reduce the perceived benefits of electric cars, which "emit" fumes at power plants.

The $120 billion price tag refers mostly to the health impact from air pollution created by electricity production and transportation, the report said.

It doesn't account for the effects on our climate, ecosystems and national security, however. Nor does it reflect the impact of certain types of pollutants such as mercury, the report said.

Coal-fired power plants accounted for a big chunk of the hidden costs. Pollutants such as sulfur dioxide, nitrogen oxide and particulate matter from 406 coal-fired power plants in the country made up $62 billion in damage, or an average of 3.2 cents for every kilowatt-hour produced, the report said. These power plants generated 95 percent of the coal-based electricity in the United States, which has relied on coal for about half of the total electricity it needs. The pervasiveness and toll of coal, along with the chemicals required in battery production, mean that all-electric cars score only a bit better than gas cars and worse than hybrids.

Natural gas-burning power plants polluted less. A look at 498 natural bas-based power plants revealed about $740 million in damage, or an average of $0.16 cents per kilowatt-hour.

The report went on to say that wind power, which accounts for just 1 percent of the electricity generation in the United States, poses far less damage than coal or natural gas. Ditto for nuclear power plants, which provided 20 percent of the power supply in 2005.

But the report cautioned that the costs associated with nuclear could go up if uranium mining pollutes ground or surface water or if mine workers are exposed to radioactive substances. Since the United States only contributes to 5 percent of the uranium production worldwide, most of the health impact would take place outside of the country, the report added.

The report also examined heat generation since heating buildings and using heat for industrial production made up 30 percent of the country's overall energy demand. Natural gas is the primary source of heat generation and accounted for $1.4 billion in damage in 2005.

That figure breaks down to 11 cents per thousand cubic feet for residential and commercial buildings, the report said. 

The transportation industry, on the other hand, generated $56 billion in damage, a bulk of which came from producing cars and fuels. 

Photo via Flickr/Creative Commons.