See
Proposed Stricter OSHA Regulations on Airborne Silica Exposure Seem Needless by Paul C. "Chip" Knappenberger of Cato.
"The U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) is soon set
to release new exposure limits to air-borne silica dust. The rulemaking
has been in the works for about three years with a final rule scheduled
to be announced this year. The silica industry is not enthused.
Silica dust is known to cause respiratory illnesses (e.g., silicosis,
lung cancer, other airways diseases) that may contribute to or lead
directly to death when it is breathed in high enough concentrations over
long enough time periods.
OSHA explains
that exposure to respirable silica “occurs in operations involving
cutting, sawing, drilling and crushing of concrete, brick, block and
other stone products and in operations using sand products, such as in
glass manufacturing, foundries and sand blasting.”
OSHA’s proposal, generally, is to lower the existing permissible
exposure limits (adopted in 1971) by about 50%, dropping them from
around 0.1mg/m3 to 0.05mg/m3 (specific details here). OSHA explains:
The agency currently enforces 40-year-old permissible
exposure limits (PELs) for crystalline silica in general industry,
construction and shipyards that are outdated, inconsistent between
industries and do not adequately protect worker health. The proposed
rule brings protections into the 21st century.
And, as the government likes to claim with all of its regulations, the added restrictions will save lots of lives, and in doing so, will save lots of money:
OSHA estimates that the proposed rule will save nearly
700 lives and prevent 1,600 new cases of silicosis per year once the
full effects of the rule are realized.
The proposed rule is estimated to provide average net benefits of about $2.8 to $4.7 billion annually over the next 60 years.
Interestingly, a visit to the Centers for Disease Control in search of deaths from silica inhalation produces this chart
graphing silicosis mortality over time. The numbers have dropped
considerably over the past 40+ years, and by 2010 had fallen to about
100 or so deaths per year (U.S. residents over the age of 15) attributed
to silicosis as either the underlying or contributing cause.
Figure 1. Silicosis: Number of deaths, crude and age-adjusted death rates, U.S. residents age 15 and over, 1968–2010 (Source:
CDC).
The CDC data shows that silicosis deaths have been declining and although the decline has slowed, it continues to drop while under the current OSHA guidelines.
And further, the 100 or so deaths that are occurring annually are
several times less than the annual number of deaths that OSHA predicts
will be saved by the new regulations. That’s a pretty neat trick—the new
regs are going to save several times more lives than are actually lost!
This means not only that the OSHA mortality benefits from the new
regulations are questionable, but so too must be the economic benefits
(as they are tied directly to the mortality savings).
The silica industry isn’t taking this lightly.
They contend that the OSHA mortality projections are based on
dose-response relationships that are not truly indicative of what is
really going on, for several reasons, primarily that they are based upon
poor and inadequate data and analyses.
Dose-response curves used by the federal government are notorious
for producing forecasts of a much greater health benefit than actually
occurs. For one reason, often, the federal dose-response curves aren’t
actually curves at all, but are rather straight lines. Which means that
the response is the same for all dosage increments. This allows
government regulatory agencies to claim the continually cranking down
the exposure limits will continually produce positive health outcomes.
But, more and more research is proving that this is not the case. As
the dose gets lower, the response often flattens out (i.e. there is a
threshold) or may in fact become positive (low dosages are actually good
for you). While this sounds like common sense to most of us (consider
sunshine or alcohol), it is a ground-breaking notion in the field. And
much of the research on this groundbreaking theory is being done by Dr. Edward Calabrese at University of Massachusetts, also an adjunct scholar to Cato’s Center for the Study of Science.
A leading industry group (the National Industrial Sand Association, NISA) makes a strong case
that the existing OSHA standards are quite effective at greatly
reducing, or even eliminating, occurrence of silicosis. So really, all
OSHA needs to do is unify the existing regulations and better insure
that they are enforced.
NISA has commissioned
a scientific study of the dose-response behavior that is wider in scope
and includes a greater and more detailed amount of epidemiological data
than the existing studies relied upon by OSHA. From a NISA report:
While the association between silicosis and exposure to
respirable crystalline silica is indisputable, there is still
considerable uncertainty regarding the dose/response relationship of
this association, particularly in the case of chronic simple silicosis,
which is the most common form of silicosis. It is unclear, for example,
whether there is an effect threshold, or whether instead the
dose/response curve is linear at even the lowest doses. The slope of
that curve is also uncertain. As a result, there is uncertainty
regarding the degree of risk remaining at various 8 hour time-weighted
average exposures, including, most importantly, the current PEL of [0.10
mg/m3].
In NISA’s view, this degree of uncertainty is unacceptable for a rulemaking of this magnitude.
The industry is being up-front about their commission (involving
scientists at major universities involved in silica research) and has
taken steps to be open and transparent about their involvement—or rather
lack of involvement—in the study’s outcome.
But, the results of the new study, instigated several years ago, are
still forthcoming and consequently the industry has asked OSHA to wait
until they are available (expected later this year) before issuing its
final rule.
It’ll be interesting to see how this plays out, but preliminarily,
this looks like another case of the government solving a problem that
doesn’t really exist, in that existing regulations are sufficient to
address the health concerns if they were better applied and enforced,
and further, the promise of the new regulations is being greatly
overplayed, saving many times more lives than our CDC says silicosis
takes away.
But that’s the government at work—if some regulations are good, more
must be better. Sadly, for the taxpayers and the regulated industries,
it doesn’t always work out that way."
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