BLUE RIDGE ENVIRONMENTAL DEFENSE LEAGUE
www.BREDL.org
~ PO Box 88 Glendale Springs, North Carolina
28629 ~ Phone (336) 982-2691 ~ Fax (336) 982-2954
~ BREDL@skybest.com
February 10, 2003
Marion E. Deerhake
Air Quality Committee
Chair
NC Environmental
Management Commission
1617 Mail Service
Center
Raleigh, NC 27699-1617
Re: Acceptable
Ambient Levels for Hydrogen Sulfide, H2S,
CAS No. 7783-06-4
Dear Chairwoman
Deerhake:
On behalf of the
Blue Ridge Environmental Defense League, I write
to request that the Environmental Management
Commission set hydrogen sulfide levels at the
lowest possible level for the protection of
public health under the NC Toxic Air Pollutant
rules. We recommend that the Commission adopt the
lowest exposure level recommended by the NC
Science Advisory Board: 0.023 ppm (23 micrograms
per cubic meter) for both the 24-hour average and
for 1-hour average acceptable ambient level, or
AAL.
North Carolina air
toxic regulations currently regulate hydrogen
sulfide as a 1-hour acute irritant with an AAL of
2.1 mg/m3, or 2100 ppb. However,
hydrogen sulfide presents serious risks to public
health both from lone facilities and from
multiple facilities in a given area. For the last
four years we have conducted an investigation of
asphalt industry facilities in the Milford Hills
neighborhood of Salisbury, NC. This community is
host to several H2S-emitting
facilities including asphalt storage, blending,
and testing facilities, and a hot mix asphalt
plant. Hydrogen sulfide is emitted from all these
facilities.
| Asphalt
storage facilities are listed in the U.S.
EPA’s hydrogen sulfide emissions
report to Congress (Report to Congress on
Hydrogen Sulfide Air Emissions Associated
with the Extraction of Oil and Natural
Gas, October 1993, EPA OAQP&S,
EPA-453/R-93-045). Stack testing
required by NC DENR at an asphalt liquid
binder plant found that levels of
hydrogen sulfide were 2400 ppm (Letter to
Winston Smith, EPA IV, from Dr. Richard
Weisler, June 23, 2002).
The NC DAQ
Air Toxics Analytical Support Team found
emissions of hydrogen sulfide from the
Associated Asphalt distribution terminal
to be 0.3 pounds/hour from a storage tank
vent, 0.000017 pounds/hour from truck
load-out vent, and 0.0061 pounds/hour
from a single railcar and 0.11
pounds/hour from an 18 car shipment.
(ATAST Investigation No. 01007 and 01008,
April 30, 2002)
The same
ATAST study estimates that the nearby
APAC hot-mix asphalt plant, typical of
the 140+ asphalt plant located across the
state, emits hydrogen sulfide at 0.7
pounds/hour.
Material
Safety Data Sheets for asphalt plants
list hydrogen sulfide as a hazardous
ingredient of common hot mix asphalt (http://www.graniterock.com/products/msds/hotmixasphalt.htm)
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As
you know, many other sources of hydrogen sulfide
exist in North Carolina: intensive swine
operations, slaughterhouses and rendering plants,
paper and pulp mills, municipal waste landfills,
and sewage treatment plants. As we have observed
in Salisbury and elsewhere, many communities are
situated within short range of more than one type
of facility. Hydrogen sulfide is one of the most
common toxic air pollutants. North Carolina must
take multiple facilities into account by setting
lower, more conservative ambient limits.
Two syndromes may
be identified as causing the symptoms reported by
residents living near hydrogen sulfide sources:
1) Recent medical
research reveals that permanent central nervous
system damage may occur at levels of H2S
exposure found at common industrial facilities
such as intensive livestock operations and
asphalt industry sites (Legator, Marvin S, and
Chantele Singleton: 1997: Panel on Hydrogen
Sulfide,American Public Health Association's
annual meetings, November 11, 1997,
Indianapolis,IN.)
2) Noxious odors
alone can cause serious and debilitating injury.
Research at Duke University found that people who
live or work around foul odors often become
depressed and irritable; the olfactory region of
the brain is closely linked to the limbic system,
the area that governs emotions. Schiffman, S.S.
& Nagle, H.T. Effect of environmental
pollutants on taste and smell. Otolaryngology
- Head & Neck Surgery 106: 693-700, 1992
Reliance on odor
regulations for control of hydrogen sulfide would
not be protective of public health. The
well-intentioned Control and Prohibition of
Odorous Emissions (15A NCAC 2D.1806) is a flawed
rule with virtually no enforcement. The
requirement for determination of an
“objectionable odor” under 2D.1806 is
that it shall be done by 1) a determination by
DAQ staff with a site visit determines , 2) an
epidemiological study submitted to DAQ regarding
the facility’s emissions, or 3) a report
from the state health director on the facility in
question. The part of the rule which allowed
“substantive complaints” from
households to be used for enforcement was
eliminated a few years ago. We believe that
2D.l806 creates a bureaucratic bottleneck which
requires enforcement to rely on limited
inspection resources of the Division, a
scientific study of each potentially
objectionable odor-causing facility, or the
particular attention of the state health
director. Moreover, the SAB reports that
“virtually everyone could detect H2S
at 200 ppb,” a level which is far less
protective of public health than the recommended
AAL (JJH 10/2/01). Of course, the rule before the
EMC today is not the odor rule; we raise this
issue to show that the toxic air pollutant
standards are the only effective rules which we
may depend on to control hydrogen sulfide
emissions.
Lower levels of
hydrogen sulfide are now known to cause serious
health effects. The NC SAB reports that
“symptoms such as headache, nausea and eye
and throat irritation” are found in
communities with ambient levels “as low as 7
to 10 ppb” associated with periodic
fluctuations at higher levels (JJH 10/2/01).
What’s more, hydrogen sulfide levels may be
elevated in cooler seasons and at night when the
gas tends to remain at ground level.
| “Public
health scientists now recognize that
hydrogen sulfide is a potent neurotoxin,
and that chronic exposure to even low
ambient levels causes irreversible damage
to the brain and central nervous system.
Children are among the most susceptible
to this poison gas. It is unacceptable
for communities to have to continue
suffering the ill effects of H2S
when the technology to control H2S
emissions is available and
affordable.” Neil Carman, Ph.D.,
former Texas environmental official
and clean air
director for the Lone Star Chapter of the
Sierra Club
|
We
think the most reasonable course for the
Environmental Management Commission is to heed
the recommendation of the Science Advisory Board
and designate the new hydrogen sulfide AAL at
0.023 ppm for both acute and long-term periods.
I plan to attend
the Air Quality Committee meeting on Wednesday,
February 12th. If possible, I would
like to have the opportunity to deliver brief
remarks on this agenda item. I would bring up
issues which no other representative will
address.
Thank you for all
you do for North Carolina.
Respectfully
submitted,
Louis Zeller
Clean Air Campaign
Coordinator
Blue Ridge
Environmental Defense League
PO Box 88
Glendale Springs, NC
28629
(336) 982-2691
BREDL@skybest.com
more info: Hydrogen sulfide
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