That really depends on how you define pollutant. For the purposes of this column, let's put aside greenhouse gases and the eventual effects of climate change and focus on more tangible pollutants, starting with the ones that make their way from industry into communities nearby. A nonprofit group called the Blacksmith Institute reports on these at the end of every year. The group's most recent study examined key pollutants at toxic sites in 49 countries and concluded that lead pollution from mining, smelting, and recycling (the latter often done from car batteries) accounted for the most pervasive risk to human health in 2012. The group estimates that lead affects at least 16 million people around the world.
Excessive lead exposure can lead to kidney problems, reduced IQ or learning disabilities, growth impairments, and nerve disorders. Acute poisoning may result in seizures and death. The only upside of environmental lead is that unlike, say, emissions of CO2, it may be on the wane. Many countries have already phased out leaded gasoline, and others are soon to follow. Old cathode ray tubes were full of lead, but we're moving away from those as well.
Other old technologies continue to be a problem. The World Health Organization has found that almost two million people perish every year from the effects of indoor smoke—from burning coal or wood or dung inside the home. And Rick Hind, legislative director at Greenpeace, wonders whether the greatest risks might be those we don't yet understand. There are 60,000 or 70,000 chemicals in commercial use, he explains, yet only about 200 have been thoroughly assessed by the EPA. "A very small percentage of the chemicals that we're swimming in—in our air, our water, and our food—have been tested for all the things that they can do to us," he says. That means the worst pollutant in the world may not yet be known.
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There are those industrial pollutions that take 10 or more years to produce a negative health hazard. Then when it is finally notice, because of the length of time can be in denial and then it takes another 10 years to prove it, mean while the companies profite and people continue to get sick.
It sounds like the worst pollutants are already well known: indoor smoke and lead. Do you know of any other pollutants that kill 2 million a people every year like indoor smoke? Or that impair 16 million people a year like lead? Let's fix those then worry about the ones "we don't yet understand."
The fact that Greenpeace is more concerned about imaginary pollution than the stuff that's actually killing people right now speaks volumes about their monumentally inverted sense of perspective.
I think the worst pollution in the world is not a chemical but a by-product of mankinds propensity to distort facts--it's called calumny and it's evil twin caricature.
Both distort the truth by feeding lies--either to hurt or to throw people off the truth.
The picture under the headline is a stupid choice. No doubt the power station produces pollutant, but the steam from the cooling towers is not the problem. The poor buggers that suffer from indoor smoke, would be a lot healthier if they could cook with electricity. Even if the production of it pollutes.
Humans are the worst pollutant in the world....
African Rover I thought nobody else would notice.
I really would like to see a comparison between coal mining and nuclear power. Pollution effects, related deaths etc.
Its hard to take people seriously on any problem when they purpose ignore the obvious solutions.
@African Rover: I've come to expect pictures of cooling towers used to represent pollution, in general-interest magazines. They have no place in a magazine that purports to be about "science". The editors of Popular Science should hang their heads in shame.
Humans are ruining the earth. Pollution is in almost everything, Cars, factories, and smokers dont realize that they have a huge part in pollution.
Those are cooling towers, and that "toxic" vapor is water vapor, be more careful with this, it's embarrassing.
check "cooling tower" on wikipedia.
in response to Teotwawki:
2,3,7,8 tetrachloro-dibenzo-dioxin is particularly nasty as its molecular structure is unusually congruent with human DNA and fits somewhat like a puzzle, causing all sorts of mutations.
please go away....you're a disgrace to the progress of intelligent lifeforms