The Chron has a followup story on metal recycling and hexavalent chromium.
Houston air experts plan to deepen their investigation into the air outside metal recycling companies after their measurements showed – apparently for the first time – that the businesses could be a source of potent fumes known to cause cancer.
“We are searching for money for more in depth testing, and also to get a feeling for what good controls would be,” said Loren Raun, an environmental statistician at Rice University, who works with the city of Houston.
Now the nation’s fourth largest city plans to expand its investigation of communities where the air may be affected. This week the Bureau of Pollution Control and Prevention’s mobile air monitoring lab returns to service following maintenance. On one of its first assignments, it will go to Holmes Road Recycling in the south of the city. Managers there are about to test a new vacuum system that operates while a worker is torching: It pulls smoke through a cyclone system to remove particles.
“In theory, it should make a significant difference in smoke and particles from any facility using the equipment properly,” said Don Richner, an analytical chemist with the Bureau of Pollution Control and Prevention.
If the new device makes a difference, the city could encourage other recyclers to employ it.
Another result of the testing is that Houston officials are questioning whether recyclers are exempt from the requirement to obtain air pollution permits. Businesses that pollute below a certain threshold are allowed to operate under what’s known as “Permit by Rule,” in which they state emissions are low. Pollution bureau chief Arturo Blanco said authorities will ask for proof.
Rice University’s Raun says researchers hope to return to the plants to test at a distance of one or two blocks. “We want to get a feel for what people farther out in the neighborhood are exposed to,” she said.
This would address a question raised by scientists that hexavalent chromium converts quickly to a less dangerous form of the metal. The city is collaborating with community groups, the University of Texas and Rice University in an application for a federal grant to pursue that research.
Background here. This sure seems like the sort of thing for which grant money ought to be granted. It’s groundbreaking research, and it could affect the way the EPA calculates the risks of air pollution. I look forward to seeing what their further tests find out.