Another Reason to Laugh When They Say that Concrete is Green

concrete kids photo

They are just so cute, those kids on the cement promotion site. The concrete manufacturers advertise themselves as green, and whenever we go to the trade shows, all the insulated form manufacturers are calling themselves "green"- there was a whole row of them at Greenbuild. My usual complaints are the amount of Carbon Dioxide generated in its manufacture or the damage done by aggregate extraction; now we have a new one: cement kilns are among the worst emitters of mercury on the continent.

cement plant in china

Julian Hewitt

According to Earthjustice, the 150 cement kilns in the United states pump out close to 23,000 pounds of mercury per year, and that it is being consciously under-reported by the manufacturers.

Our report told the stories of underreporting happening across the country. For instance, a cement kiln in Alpena, MI, reported emitting only 66 pounds of mercury; after the state required the facility to test its emission, test data showed the kiln actually emitted over 560 pounds of mercury. In Ravena, NY, just south of Albany, a Lafarge cement kiln reported mercury emissions in 2002 of only 40 pounds; actual emissions testing in 2004 revealed the kiln was emitting over 400 pounds of mercury.

Mercury is a potent neurotoxin that can impair a child's ability to walk, talk, read, write and learn. Because it damages developing nervous systems, exposure to mercury is especially dangerous for unborn babies, infants, and young children. Mercury also puts adults at risk, however. It can affect fertility and blood pressure regulation, and can cause memory and vision loss, tremors, and numbness in the fingers and toes.

Earthjustice notes that the Environmental Protection Agency relies on voluntary estimates reported to their toxic release inventory. They want this changed:

We recommend that the EPA adopt standards that include the following:

* State and federal regulatory agencies should require specific testing for mercury emissions;
* Continuous Emissions Monitoring Systems (CEMS) should be installed in every cement kiln to measure mercury emissions accurately and provide real-time data these emissions;
* EPA must require cement kilns to install mercury pollution control devices. Some states can and should take action without waiting for EPA by immediately requiring kilns within their jurisdiction to apply these devices

The Clean Air Act requires EPA to identify categories of facilities that are major sources of toxic air pollutants and set emission standards for each category, such as cement kilns. There are effective and affordable technologies out there and it is time the EPA does its job and requires these facilities to clean up their pollution.

There is no question that concrete is indispensable; it is hard to build bridges and highrises without it. But peddling it as green when it is clearly not is just greenwashing.

Earthjustice via Celcias

More on TreeHugger on Green Concrete:

GreenBuild: Durisol, the Green Insulated Concrete Form :
Insulated Concrete Forms: Another Opinion
Concrete: Can it be Green?