Air quality

In a case of good news/bad news for industrial workers, OSHA (the Occupational Safety and Health Administration) is getting a budget increase for 2012, but the money comes with a delay on a proposal that would further limit workers’ exposure to carcinogenic silica dust.

The backstory: Last February OSHA sent a proposal to the White House Office of Management and Budget that called for a reduction in the silica PEL¹ (Permissible Exposure Limit), which would be the first change to this regulation since the 1960’s². The plan was to get the approval of the OMB and then open up the proposal to public debate after 90 days, but one year later and OSHA is still waiting.

The reason for the snag is most likely because of concerns raised by the industries that would be financially affected by stricter controls. Some opponents of the new OSHA proposal argue that the government needs to do a better job of enforcing the current rules before making any changes to the exposure level. Congress seems to agree with this priority, as the largest line item increase in the new budget is $5 million for additional enforcement OSHA’s sister organization, MSHA (Mine Safety and Health Administration). Representatives for the impacted industries, such as construction and mining, also point out that they subject themselves to voluntary monitoring and medical treatment for certain silica levels and these measures have been effective at eliminating the health risks to workers.

Unfortunately for those who disagree with that assessment, a stricter regulation is unlikely to happen in the immediate future since with the upcoming elections lawmakers aren’t in a hurry to pass a regulation that could paint them as “anti-business.” So at least for now OSHA is going to have to use their bigger budget to make the current regulations work.

For more information on the new OSHA budget we recommend this piece by NPR and this writeup from Patton Boggs LLP.

1)  The PEL for silica is a little tricky to explain – there are several variables and conditions that prevent it from being expressed as a simple number. You can read this blog post from The Safety Director’s Cut for a detailed explanation.

2) While the acceptable levels may change, there aren’t any expected changes to the recommended procedure for evaluating crystalline silica – which involves filtering samples on silver membrane filters and X-Ray Diffraction analysis. You can find the full procedure from the CDC here.

This week the Occupational Safety and Health Administration (OSHA) fined a carbon steel foundry in Wisconsin $95,480 for willfully overexposing their workers to crystalline silica, a known carcinogen. Ironically, this news comes shortly after a group of citizens petitioned the Wisconsin Department of Natural Resources (DNS) to adopt more stringent rules governing emissions of respirable crystalline silica.

Crystalline silica is a particularly dangerous air pollutant because it is a basic component of soil, sand, brick, granite and other common materials. As a byproduct of many everyday industrial processes like mining, construction, and glass manufacturing, it is a ubiquitous presence for some workers. Industrial processes that involve abrasive blasting or the use of sand and quartz are also sources of crystalline silica exposure, which is why many of these workers are concerned over the increasing popularity of fracking in their state. The hydraulic fracturing (AKA “Fracking”) process involves fracturing rock layers with a fluid that includes sand or ceramic material in order to extract the gas underneath. As you can tell from the description, stirring up compressed rock dust and sand particles is a definite health concern, so it’s good to see those at risk aware of it and addressing the matter.

The petitioners are asking the Wisconsin DNS to classify respirable crystalline silica as a hazardous air pollutant under their air toxics rule. Furthermore, the petitioners recommend that the DNS comply with the standard set by the State of California Office of Environmental Health Hazard Assessment which dictates a limit of 3 micrograms per cubic meter and requires consistent monitoring and enforcement.

Determining the concentration of crystalline silica and amorphous silica by the National Institute for Occupational Safety and Health (NIOSH) standards requires capturing particulates from an air sample on a 0.45 micron, 25 mm diameter Silver Membrane Filter and then analyzing the particulate matter for silica using X-Ray diffraction (XRD). See NIOSH methods 7500 and 7501 for the complete procedure.

Read the full petition by Wisconsin citizens here.
Also see this report on silica from the Wisconsin DNS.

Coal miners could be at greater risk to lung ailments caused by air-borne contaminants such as crystalline silica, according to a new NIOSH (National Institute for Occupational Safety and Health) publication. After reviewing information that had been published over the last 15 years the agency determined that miners may face increased exposure to these harmful materials as the more productive seams of coal are mined out, forcing them to dig deeper into thinner mining seams. The result is longer working hours in environments that have denser concentrations of crystalline silica, creating respiratory and pulmonary disease.

NIOSH is responsible for setting guidelines on exposure levels of damaging substances like crystalline silica as well as recommending the sampling procedures for these toxic particles. The NIOSH sample technique for crystalline silica involves redepositing the sample onto a 0.45 micron, 25 mm silver membrane filter for analysis by x-ray diffraction. Testing for air-borne contaminants is one of the most common applications for our silver membranes. NIOSH did not make any changes to the sampling method in their new report. In fact, these new findings strengthen their concerns about the respiratory health effects caused by coal mine dust.

Today the Environmental Protection Agency awarded $32 million to 4 universities around the country to study the health impacts of air pollution. These centers will answering questions like, "does air pollution effect a child's learning ability?" "Are obese people more susceptible to health effects of air pollution?" "How does your commute effect your health?"

We work with a number of environmental labs to provide filtration materials, and one of the most common requests we get from them is for our 0.45 micron, 25mm silver membranes to comply with NIOSH methods for testing airborne contaminants such as silica and bromine.

Here is a breakdown of what the four new centers are focusing on:

• University of Washington - Effects of roadway pollution on on cardiovascular health.
• Michigan State University - The relationships between obesity and air pollution.
• Emory University / Georgia Institute of Technology - Characterize health risks of air pollution mixtures, research how social factors (living location, commute, etc.) impact health.
• Harvard University - Investigate health effects of short-term and long-term exposure to pollutants on specific health functions, including cognitive function, birth weight, and mortality.

See also:
"EPA Awards $32 Million to Understand Health Impacts of Air Pollution"

EPA Clean Air Research Centers Home