Published in the American Journal of Industrial Medicine

Abstract

Hydrogen sulfide (H2S) poisoning involves a risk of hypoxic brain damage. Six patients who lost consciousness due to H2S poisoning are described. The symptoms varied from anosmia in the patient with the shortest but highest exposure to delayed neurological deterioration in the patient with the longest exposure. The two patients with the most serious symptoms developed pulmonary edema, which may have prolonged the hypoxia. The patients were reexaminated 5 years or more after the poisoning. The five patients who had been unconscious in H2S atmosphere for from 5 to 15-20 min showed persisting impairment at neurological and neuropsychological re-examination. Memory and motor function were most affected. One patient was seriously demented. Recent reports of large groups of H2S-poisoned workers probably underestimate the risk of sequelae, due to the inclusion of cases with exposure of short duration and lack of follow-up.

…..
Above abstract available from the US National Library of Medicine, National Institute of Health:  http://www.ncbi.nlm.nih.gov/pubmed/1867221.

Full document available from the California State University website:  http://www.csun.edu/~dorsogna/byron/H2Snew.pdf.

…..

Hydrogen Sulfide and Sulfides:
Sulfides are naturally occurring gasses that often give a landfill gas mixture its rotten egg smell. Sulfides
can cause unpleasant odors even at very low concentrations. Hydrogen sulfide is a colorless, flammable
gas and is one of the most common sulfides responsible for landfill odors. Some people can smell
hydrogen sulfide (individual’s odor threshold) at concentrations as low as 0.5 parts per billion (ppb).
However, the odor threshold can vary significantly among individuals based on the olfactory sensitivity of
the person. For many compounds, including hydrogen sulfide, there is a wide variability in published odor
thresholds (refer to Table 1). Odors alone cannot be relied upon as providing an early warning for
elevated concentrations of hydrogen sulfide. “At concentrations around 100 ppm,” (parts per million)
“no odor is detected due to a loss of olfactory sensation, resulting in loss of warning properties at lethal
levels.” (Integrated Risk Information System (IRIS)). Hydrogen sulfide is more dense than air, and
therefore, more likely to pool at lower elevations under still conditions, depending upon topography.

……..

Above paragraph is an excerpt from  Appendix A – Basics of Landfill Gas (Methane, Carbon Dioxide, Hydrogen Sulfide and Sulfides):  http://www.mass.gov/dep/recycle/laws/lfgasapp.pdf 

The full document is Control of Odorous Gas at Massachusetts Landfills (http://www.mass.gov/dep/recycle/laws/lfgaspol.pdf) published on the website of the

COMMONWEALTH OF MASSACHUSETTS
EXECUTIVE OFFICE OF ENVIRONMENTAL AFFAIRS
DEPARTMENT OF ENVIRONMENTAL PROTECTION

July 2006

(The document introduction “Public Health Statement” is shown below.   The Table of Contents and a link to the full 253-page document are listed further down.)

1. PUBLIC HEALTH STATEMENT

This public health statement tells you about hydrogen sulfide and the effects of exposure to it.

The Environmental Protection Agency (EPA) identifies the most serious hazardous waste sites in
the nation. These sites are then placed on the National Priorities List (NPL) and are targeted for
long-term federal clean-up activities. Hydrogen sulfide has been found in at least 35 of the
1,689 current or former NPL sites. Although the total number of NPL sites evaluated for this
substance is not known, the possibility exists that the number of sites at which hydrogen sulfide
is found may increase in the future as more sites are evaluated. This information is important
because these sites may be sources of exposure and exposure to this substance may harm you.

When a substance is released either from a large area, such as an industrial plant, or from a
container, such as a drum or bottle, it enters the environment. Such a release does not always
lead to exposure. You can be exposed to a substance only when you come in contact with it.
You may be exposed by breathing, eating, or drinking the substance, or by skin contact.

If you are exposed to hydrogen sulfide, many factors will determine whether you will be harmed.
These factors include the dose (how much), the duration (how long), and how you come in
contact with it. You must also consider any other chemicals you are exposed to and your age,
sex, diet, family traits, lifestyle, and state of health.

…..

CONTENTS
DISCLAIMER ……………………………………………………………………………………………………………………………ii
UPDATE STATEMENT ……………………………………………………………………………………………………………..iii
FOREWORD …………………………………………………………………………………………………………………………….. v
QUICK REFERENCE FOR HEALTH CARE PROVIDERS…………………………………………………………..vii
CONTRIBUTORS……………………………………………………………………………………………………………………..ix
PEER REVIEW …………………………………………………………………………………………………………………………xi
CONTENTS…………………………………………………………………………………………………………………………….xiii
LIST OF FIGURES …………………………………………………………………………………………………………………xvii
LIST OF TABLES……………………………………………………………………………………………………………………xix
1. PUBLIC HEALTH STATEMENT……………………………………………………………………………………………. 1
1.1 WHAT IS HYDROGEN SULFIDE?……………………………………………………………………………… 1
1.2 WHAT HAPPENS TO HYDROGEN SULFIDE WHEN IT ENTERS THE
ENVIRONMENT? ………………………………………………………………………………………………………. 2
1.3 HOW MIGHT I BE EXPOSED TO HYDROGEN SULFIDE? …………………………………………. 2
1.4 HOW CAN HYDROGEN SULFIDE ENTER AND LEAVE MY BODY? ………………………… 3
1.5 HOW CAN HYDROGEN SULFIDE AFFECT MY HEALTH? ……………………………………….. 4
1.6 HOW CAN HYDROGEN SULFIDE AFFECT CHILDREN?…………………………………………… 5
1.7 HOW CAN FAMILIES REDUCE THE RISK OF EXPOSURE TO HYDROGEN
SULFIDE?…………………………………………………………………………………………………………………. 6
1.8 IS THERE A MEDICAL TEST TO DETERMINE WHETHER I HAVE BEEN
EXPOSED TO HYDROGEN SULFIDE? ………………………………………………………………………. 6
1.9 WHAT RECOMMENDATIONS HAS THE FEDERAL GOVERNMENT MADE TO
PROTECT HUMAN HEALTH?……………………………………………………………………………………. 7
1.10 WHERE CAN I GET MORE INFORMATION? …………………………………………………………….. 8
2. RELEVANCE TO PUBLIC HEALTH ……………………………………………………………………………………… 9
2.1 BACKGROUND AND ENVIRONMENTAL EXPOSURES TO HYDROGEN
SULFIDE IN THE UNITED STATES …………………………………………………………………………… 9
2.2 SUMMARY OF HEALTH EFFECTS………………………………………………………………………….. 10
2.3 MINIMAL RISK LEVELS (MRLs) …………………………………………………………………………….. 14
3. HEALTH EFFECTS…………………………………………………………………………………………………………….. 21
3.1 INTRODUCTION…………………………………………………………………………………………………….. 21
3.2 DISCUSSION OF HEALTH EFFECTS BY ROUTE OF EXPOSURE ……………………………. 21
3.2.1 Inhalation Exposure ……………………………………………………………………………………………….. 22
3.2.1.1 Death ……………………………………………………………………………………………………………. 22
3.2.1.2 Systemic Effects …………………………………………………………………………………………….. 26
3.2.1.3 Immunological and Lymphoreticular Effects……………………………………………………… 61
3.2.1.4 Neurological Effects……………………………………………………………………………………….. 62
3.2.1.5 Reproductive Effects ………………………………………………………………………………………. 68
3.2.1.6 Developmental Effects ……………………………………………………………………………………. 70
3.2.1.7 Cancer………………………………………………………………………………………………………….. 71
3.2.2 Oral Exposure……………………………………………………………………………………………………….. 72
3.2.2.1 Death ……………………………………………………………………………………………………………. 72
3.2.2.2 Systemic Effects …………………………………………………………………………………………….. 72
3.2.2.3 Immunological and Lymphoreticular Effects……………………………………………………… 73

3.2.2.4 Neurological Effects……………………………………………………………………………………….. 73
3.2.2.5 Reproductive Effects ………………………………………………………………………………………. 73
3.2.2.6 Developmental Effects ……………………………………………………………………………………. 73
3.2.2.7 Cancer………………………………………………………………………………………………………….. 73
3.2.3 Dermal Exposure……………………………………………………………………………………………………. 73
3.2.3.1 Death ……………………………………………………………………………………………………………. 73
3.2.3.2 Systemic Effects …………………………………………………………………………………………….. 74
3.2.3.3 Immunological and Lymphoreticular Effects……………………………………………………… 74
3.2.3.4 Neurological Effects……………………………………………………………………………………….. 74
3.2.3.5 Reproductive Effects ………………………………………………………………………………………. 75
3.2.3.6 Developmental Effects ……………………………………………………………………………………. 75
3.2.3.7 Cancer………………………………………………………………………………………………………….. 75
3.3 GENOTOXICITY ……………………………………………………………………………………………………… 75
3.4 TOXICOKINETICS………………………………………………………………………………………………….. 75
3.4.1 Absorption……………………………………………………………………………………………………………. 76
3.4.1.1 Inhalation Exposure………………………………………………………………………………………… 76
3.4.1.2 Oral Exposure………………………………………………………………………………………………… 76
3.4.1.3 Dermal Exposure ……………………………………………………………………………………………. 77
3.4.2 Distribution …………………………………………………………………………………………………………… 77
3.4.2.1 Inhalation Exposure………………………………………………………………………………………… 77
3.4.2.2 Oral Exposure………………………………………………………………………………………………… 79
3.4.2.3 Dermal Exposure ……………………………………………………………………………………………. 79
3.4.2.4 Other Routes of Exposure ……………………………………………………………………………….. 79
3.4.3 Metabolism…………………………………………………………………………………………………………… 79
3.4.4 Elimination and Excretion……………………………………………………………………………………….. 82
3.4.4.1 Inhalation Exposure………………………………………………………………………………………… 82
3.4.4.2 Oral Exposure………………………………………………………………………………………………… 82
3.4.4.3 Dermal Exposure ……………………………………………………………………………………………. 83
3.4.5 Physiologically Based Pharmacokinetic (PBPK)/Pharmacodynamic (PD) Models …………. 83
3.5 MECHANISMS OF ACTION …………………………………………………………………………………….. 84
3.5.1 Pharmacokinetic Mechanisms………………………………………………………………………………….. 84
3.5.2 Mechanisms of Toxicity………………………………………………………………………………………….. 86
3.5.3 Animal-to-Human Extrapolations …………………………………………………………………………….. 88
3.6 TOXICITIES MEDIATED THROUGH THE NEUROENDOCRINE AXIS…………………….. 88
3.7 CHILDREN’S SUSCEPTIBILITY………………………………………………………………………………. 89
3.8 BIOMARKERS OF EXPOSURE AND EFFECT ………………………………………………………….. 91
3.8.1 Biomarkers Used to Identify or Quantify Exposure to Hydrogen Sulfide ………………………. 92
3.8.2 Biomarkers Used to Characterize Effects Caused by Hydrogen Sulfide ………………………… 93
3.9 INTERACTIONS WITH OTHER CHEMICALS ………………………………………………………….. 93
3.10 POPULATIONS THAT ARE UNUSUALLY SUSCEPTIBLE……………………………………….. 95
3.11 METHODS FOR REDUCING TOXIC EFFECTS…………………………………………………………. 95
3.11.1 Reducing Peak Absorption Following Exposure …………………………………………………….. 96
3.11.2 Reducing Body Burden……………………………………………………………………………………….. 97
3.11.3 Interfering with the Mechanism of Action for Toxic Effects ……………………………………. 97
3.12 ADEQUACY OF THE DATABASE……………………………………………………………………………. 98
3.12.1 Existing Information on Health Effects of Hydrogen Sulfide …………………………………… 98
3.12.2 Identification of Data Needs ………………………………………………………………………………. 100
3.12.3 Ongoing Studies……………………………………………………………………………………………….. 107

4. CHEMICAL AND PHYSICAL INFORMATION…………………………………………………………………… 109
4.1 CHEMICAL IDENTITY…………………………………………………………………………………………… 109
4.2 PHYSICAL AND CHEMICAL PROPERTIES……………………………………………………………. 109
5. PRODUCTION, IMPORT/EXPORT, USE, AND DISPOSAL…………………………………………………. 113
5.1 PRODUCTION ……………………………………………………………………………………………………….. 113
5.2 IMPORT/EXPORT ………………………………………………………………………………………………….. 113
5.3 USE……………………………………………………………………………………………………………………….. 114
5.4 DISPOSAL…………………………………………………………………………………………………………….. 114
6. POTENTIAL FOR HUMAN EXPOSURE …………………………………………………………………………….. 115
6.1 OVERVIEW…………………………………………………………………………………………………………… 115
6.2 RELEASES TO THE ENVIRONMENT…………………………………………………………………….. 118
6.2.1 Air …………………………………………………………………………………………………………………….. 118
6.2.2 Water…………………………………………………………………………………………………………………. 119
6.2.3 Soil ……………………………………………………………………………………………………………………. 120
6.3 ENVIRONMENTAL FATE………………………………………………………………………………………. 121
6.3.1 Transport and Partitioning……………………………………………………………………………………… 121
6.3.2 Transformation and Degradation ……………………………………………………………………………. 122
6.3.2.1 Air……………………………………………………………………………………………………………… 122
6.3.2.2 Water ………………………………………………………………………………………………………….. 122
6.3.2.3 Sediment and Soil…………………………………………………………………………………………. 123
6.4 LEVELS MONITORED OR ESTIMATED IN THE ENVIRONMENT…………………………. 123
6.4.1 Air …………………………………………………………………………………………………………………….. 124
6.4.2 Water…………………………………………………………………………………………………………………. 127
6.4.3 Sediment and Soil ………………………………………………………………………………………………… 127
6.4.4 Other Environmental Media…………………………………………………………………………………… 128
6.5 GENERAL POPULATION AND OCCUPATIONAL EXPOSURE ………………………………. 129
6.6 EXPOSURES OF CHILDREN………………………………………………………………………………….. 131
6.7 POPULATIONS WITH POTENTIALLY HIGH EXPOSURES ……………………………………. 132
6.8 ADEQUACY OF THE DATABASE………………………………………………………………………….. 132
6.8.1 Identification of Data Needs ………………………………………………………………………………….. 133
6.8.2 Ongoing Studies …………………………………………………………………………………………………… 135
7. ANALYTICAL METHODS ………………………………………………………………………………………………… 137
7.1 BIOLOGICAL MATERIALS……………………………………………………………………………………. 137
7.2 ENVIRONMENTAL SAMPLES……………………………………………………………………………….. 143
7.3 ADEQUACY OF THE DATABASE………………………………………………………………………….. 151
7.3.1 Identification of Data Needs ………………………………………………………………………………….. 151
7.3.2 Ongoing Studies …………………………………………………………………………………………………… 152
8. REGULATIONS AND ADVISORIES ………………………………………………………………………………….. 153
9. REFERENCES ………………………………………………………………………………………………………………….. 159
10. GLOSSARY ……………………………………………………………………………………………………………………. 201

……

Full document:  http://www.atsdr.cdc.gov/toxprofiles/tp114-p.pdf

…..

MAJOR CONCLUSIONS IN THE CHARACTERIZATION OF HAZARD AND DOSE RESPONSE

6.1. HAZARD IDENTIFICATION

Hydrogen sulfide is a colorless gas and has a strong odor of rotten eggs. Its primary uses include the production of elemental sulfur and sulfuric acid, the manufacture of heavy water and other chemicals, in metallurgy, and as an analytical reagent. Although quantitative data are lacking, toxicity studies suggest that H2S gas is absorbed rapidly through the lungs. Oral exposure is not likely to occur. In animals and humans, it distributes to the blood, brain, lung, heart, liver, spleen, and kidney. Oxidation is the primary metabolic pathway for H2S, with thiosulfate and sulfate as metabolites. Metabolism in laboratory animals and in humans appears to be similar. Hydrogen sulfide is excreted in the urine.

Human data pertaining to inhalation exposure (the expected route of ambient exposure) consist of a plethora of case reports and a variety of occupational epidemiological studies. Although these studies have limitations that preclude their use for quantitative risk assessment, they indicate that exposure to H2S (at high concentrations) has profound effects on the respiratory system leading to unconsciousness with attendant neurologic sequelae and, sometimes, death. An increase in cardiovascular-related deaths due, in part, to H2S exposure was reported in one occupational study.

Inhalation studies in adult rodents demonstrate sensitivity of nasal olfactory epithelium to low concentrations of H2S. The RfC is based on these lesions. Limited evidence suggests that exposure of humans to low concentrations may also cause neurologic symptoms although quantitative exposure-response data is lacking. Because of similar access of inhaled H2S to the olfactory tissues of humans, these lesions are likely of relevance to humans and a reasonable choice as a critical effect. Relevance to olfactory lesions seen in rodents to humans is also suggested by Hirsch and Zavala (1999) who reported decreased persistent olfactory function in workers exposed to hydrogen sulfide chronically. Whereas adverse nasal effects are of relevance and concern in adult human exposure scenarios, inhalation studies of perinatal or neonatal exposure in rats demonstrates abnormal cellular development in the brain as well as significant alterations in neurotransmitter levels; the toxicological significance of these findings is uncertain.

Relevant quantitative human oral toxicity data are not available and ingestion is not a likely route of exposure. An RfD based on GI disturbances in pigs consuming feed containing hydrogen sulfide was derived in the previous IRIS entry. A review of the RfD (see Section 4.2.1) indicates that the effects on which that value were based are not reproducible and probably not related to H2S. Therefore the previous RfD will be withdrawn and a new RfD will not be derived based on data base deficiencies.

The indicators of a possible effect noted in the developing brain cells of newborn rats indicate the possibility that the developing human fetus could also be at risk. The exposure levels producing these effects, however, are in the same range or somewhat higher than those producing the critical sentinel clearly adverse effect (nasal tract lesions) in adult animals, thereby ameliorating the concern that young animals (and possibly children) may be especially susceptible to the effects from relatively low-level chronic exposures to hydrogen sulfide. Other observations in the data base do indicate a possible concern regarding the susceptibility of children exposed to high levels of H2S, i.e., > 600 ppb. However, the relevance of this apparent susceptibility at environmental levels of H2S where toxicity is not likely to occur, such as the RfC value derived herein, is not at all clear.

There is no evidence indicating that H2S exposure is associated with carcinogenesis. Under the Draft Revised Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1999), data are inadequate for an assessment of the carcinogenic potential of hydrogen sulfide.

…..

Link to Full Document:  http://www.epa.gov/IRIS/toxreviews/0061tr.pdf

Intro/Letter excerpt:  (from http://www.earthworksaction.org/library/detail/hydrogen_sulfide_needs_hazardous_air_pollutant_listing_under_caa_title_iii)

The community, environmental, and public health organizations named below request that you formally list Hydrogen Sulfide (H2S) as a hazardous air pollutant (HAP), as defined in Title III, section 112(b) of the 1990 Clean Air Act Amendments (CAA). We assert that EPA must act to address adverse H2S impacts based on evidence of harmful exposures in numerous communities and its toxicological effects at low concentrations such as non-cancer effects and emerging evidence that H2S is a genotoxic agent, meaning it damages DNA. EPA has assessed the need to list H2S as a HAP, but no formal listing action has been taken. H2S is clearly an unlisted hazardous air pollutant.

……
(Full letter can be viewed at: http://www.earthworksaction.org/files/publications/H2SLetterToEPA.pdf)
……

Conclusion  

Public health scientists have recognized for over a decade that hydrogen sulfide is a potent neurotoxin, and chronic
exposure to low ambient levels causes irreversible damage to the brain and central nervous system. Ultra-low levels
of H2S down to 25 ppb have been associated with acute exposure causing eye irritation in community settings in the
United States, Europe and New Zealand. Now emerging scientific evidence supports H2S causes neuron death,
confirming findings by Kilburn of irreversible brain damage. The latest scientific findings suggest H2S causes DNA
damage as a genotoxic agent, which EPA can no longer ignore. The potential carcinogenic implications of H2S
demand that EPA act to protect public health.

Children are among the most susceptible to this poison gas, and EPA needs to do a more effective job of protecting
schoolchildren from H2S impacts. Today, it is unacceptable for communities to have to continue suffering the ill
effects of H2S when the technology to monitor and control H2S emissions exists. As EPA has learned in the last four
decades, environmental injustice is a significant fact of life for thousands of communities in this nation and these
residents all have a right to clean, safe air.

It’s time for the EPA to take action to formally acknowledge hydrogen sulfide’s clear toxicity at low concentrations.
As Administrator, you have CAA authority under section 112(b)(2) to act based on a pollutant that poses or may
pose “…a threat of adverse human health effects…” Health studies confirm the need for EPA to list H2S under
section 112(b) of the CAA and Title III, since routine daily exposure effects are not addressed under the accidental
release provisions in section 112(r) of the CAA, where H2S is currently regulated. However, section 112(r) is not
designed or intended to address daily exposures at sublethal concentrations, but section 112(b) can bridge this gap.

EPA, in addition, needs to require annual reporting of H2S as a toxic substance under the Toxic Release Inventory
(TRI) reporting program, since H2S is not reported due to an administrative stay issued August 22, 1994 evidently
under a legal threat by the American Petroleum Institute. It’s extraordinary that industry has delayed reporting of
H2S for twenty years. EPA needs a TRI reporting threshold of 1.0 pound for H2S and not 10,000 pounds as was
originally the requirement. We request that EPA immediately lift the administrative stay on H2S and require TRI
reporting in the next TRI submission cycle. The TRI data would also help EPA compile more accurate H2S data.

Please respond to this request for EPA to take action to list H2S under section 112(b) of the CAA. Address the
EPA’s response to Neil Carman at the contact information listed below.

Respectfully yours,

Neil J. Carman, Ph.D.
Sierra Club’s Clean Air Team and the
Lone Start Chapter of the Sierra Club
1202 San Antonio St, Austin, TX 78701
Tel 512-472-1767; Fax 512-477-8526

(This letter was also sent/signed by the following organizations:   National Environmental Justice and Community Partnerships Director; Citizens for Environmental Justice; Community In-Powerment and Development Association; Earthjustice Legal Defense Fund; Environmental Integrity Project; Galveston Houston Association for Smog Prevention & Mothers for Clean Air; Global Community Monitor, National Refinery Reform Campaign & National Bucket Brigade Coalition; Downwinders At Risk; Groups Allied to Stop Pollution; The People’s Advocate; Lower Mississippi Riverkeeper; Louisiana Environmental Action Network; EARTHWORKS’, and Oil & Gas Accountability Project; San Juan Citizens Alliance; Sustainable Energy & Economic Development Coalition; Citizens Against Environmental Destruction; Northeast Ohio Gas Accountability Project; Huron Environmental Activist League; Don’t Waste Arizona; Cook Inletkeeper; Protect All Children’s Environment.)

Abstract (with author affiliations & other articles citing this article):  http://oem.bmj.com/content/56/4/284.abstract)
Full document:  http://oem.bmj.com/content/56/4/284.full.pdf+html

By Alan R Hirsch, Gilberto Zavala

Abstract 

Objective—To study chronic effects of hydrogen sulphide (H2S) on cranial nerve I (nervi olfactorii), which have been only minimally described.

Methods—Chemosensations (smell and taste) were evaluated in eight men who complained of continuing dysfunction 2–3 years after the start of occupational exposure to H2S. Various bilateral (both nostrils) and unilateral (one nostril at a time) odour threshold tests with standard odorants as well as the Chicago smell test, a three odour detection and identification test and the University of Pennsylvania smell identification test, a series of 40 scratch and sniff odour identification tests were administered.

Results—Six of the eight patients showed deficits of various degrees. Two had normal scores on objective tests, but thought that they continued to have problems. H2S apparently can cause continuing, sometimes unrecognised olfactory deficits.

Conclusion—Further exploration into the extent of such problems among workers exposed to H2S is warranted.

(Occup Environ Med 1999;56:284–287)

Occupational and Environmental Medicine (OEM) is an international peer reviewed journal covering current developments in occupational and environmental health worldwide. Original contributions include: epidemiological studies of health concerns related to exposures in the workplace and the environment; human studies employing biological and genomic techniques to investigate the effects of such exposures; exposure assessment studies; evidence based research on the practice of occupational medicine, and new research methods.

By Lana Skrtic

Submitted in partial satisfaction of the requirements for the degree of
Master’s of Science
May 2006
Energy and Resources Group
University of California, Berkeley

Full Document:  PDF File

8. Concluding Remarks

The literature on human health and hydrogen sulfide reveals serious and lasting physiological and neurological effects associated  with acute exposure.  The health effects of chronic exposure to lower levels of H2S, as documented in several studies, also include persistent physiological and neurological disturbances.   Oil and gas facilities can be expected to accidentally and routinely emit hydrogen sulfide in concentrations that span a wide range and are associated with a variety of health effects.  Academic studies, my conversations with health department staff, and available data from monitoring projects help establish that hydrogen sulfide is indeed present near oil and gas facilities.

Because people live near oil and gas sites, emissions of H2S may be routinely compromising human health.  The interviews I conducted with people who live close to oil and gas facilities, as well as some research reported in the Literature  Review section, provide evidence of health impacts from exposure to H2S emitted by oil and gas development.  Although the anecdotal  evidence from my interviews is vulnerable to criticism that other pollutants or individual health factors may be responsible for the symptoms, the reported health effects are consistent with hydrogen sulfide exposure.  The fact that concentrations of H2S to which people are exposed are often not known does not imply that hydrogen sulfide is  not the cause of the observed health effects.  The lack of precise exposure data is,  however, one area that future research should address.

……..

As I show in the Regulations and Recommendations section, at the federal level, the oil and gas industry and the paper and pulp industry have exerted their influence to prevent H2S from being included on the Clean Air Act’s Hazardous Air Pollutants (HAPs) list, and to exempt it from reporting under the EPA’s Toxic Release Inventory (TRI).  At the time of writing, the EPA is reviewing both decisions, which at the very least indicates that some concern exists over the lack of stricter regulation of hydrogen sulfide at the federal level.  The level of regulation of hydrogen sulfide varies widely across the states that have established an ambient standard in the absence of a federal one, but again, the very  existence of ambient standards suggests that hydrogen sulfide is a concern.

Monitoring of ambient H2S is necessary to determine exactly how much is being emitted and to clarify the link between exposure and health effects.  Enough evidence of routine H2S emissions at oil and gas facilities emerges from my conversations with health department personnel, interviews with people living near oil and gas sites, several studies summarized in the Literature Review section, and state monitoring projects to merit more comprehensive monitoring.  The lack of federal standards for ambient H2S levels or for emissions of H2S is one reason for sparse monitoring even at state level, since state health / environmental departments largely depend on federal funding for their projects.  More routine and special project monitoring would facilitate conducting community health studies, by providing accurate exposure data that could be matched with observed health effects.

In light of the information presented here on the health effects associated with exposure to hydrogen sulfide, even though rigorous data on the dose-response relationship is lacking, it is irresponsible and callous to delay making some public policy decisions that would help protect human health.

Full document:  http://www.kumed.com/documents/KDHEHydrogenSulfide.pdf

Full PDF file

HUMAN IMPAIRMENT FROM LIVING NEAR CONFINED ANIMAL (HOG) FEEDING OPERATIONS (CAFO’S)

Kaye H. Kilburn, M.D.

Ralph Edgington Professor of Internal Medicine
University of Southern California
Keck School of Medicine (ret.)
President- Neuro-test Inc.

ABSTRACT

Problem  To determine whether neighbors around manure lagoons and massive hog confinement buildings who complained of offensive odors and symptoms had impaired brain and lung function.

Method  We compared near hog manure neighbors of lagoons to people living beyond 3 kilometers in Ohio and to unexposed people controls in a nearby state for neurophysiological, cognitive, recall and memory functions, and pulmonary performance.

Results  The 25 exposed subjects averaged 4.3 neurobehavioral abnormalities, significantly different from 2.5 for local controls and 2.3 for Tennessee controls. Exposed subjects mean forced vital capacity and expiratory volume in 1 sec. were reduced significantly compared to local and regional controls.

Conclusions  Near neighbors of hog enclosures and manure lagoon gases had impaired neurobehavioral functions and pulmonary functions and these effects extended to nearby people thought to be controls. Hydrogen sulfide must be abated because people living near lagoons can not avoid rotten egg gas.

3. HEALTH EFFECTS

3.1 INTRODUCTION

The primary purpose of this chapter is to provide public health officials, physicians, toxicologists, and
other interested individuals and groups with an overall perspective on the toxicology of hydrogen sulfide.
It contains descriptions and evaluations of toxicological studies and epidemiological investigations and
provides conclusions, where possible, on the relevance of toxicity and toxicokinetic data to public health.

3.2 Discussion of health effects by route of exposure
3.3 Genotoxicity
3.4 Health effects in wildlife potentially relevant to human health
3.5 Toxicokinetics
3.5 Mechanisms of action
3.6 Toxicities mediated through the neuroendocrine axis
3.7 Children’s susceptibility
3.8 Biomarkers of exposure and effect
3.9 Interactions with other chemicals
3.10 Populations that are unusually susceptible
3.11 Methods for reducing toxic effects
3.12 Adequacy of the database

…..

The full chapter on Health Effects can be read online:  http://www.atsdr.cdc.gov/toxprofiles/tp114-c3.pdf.

The full Toxicological Profile for Hydrogen Sulfide (all chapters) can be referenced at:  http://www.atsdr.cdc.gov/ToxProfiles/tp.asp?id=389&tid=67 

6.6 Hydrogen sulfide

Exposure evaluation
Typical symptoms and signs of hydrogen sulfide intoxication are most
often caused by relatively high concentrations in occupational exposures.
There are many occupations where there is a potential risk of hydrogen
sulfide intoxication and, according to the US National Institute for Occupational
Safety and Health (1), in the United States alone approximately
125 000 employees are potentially exposed to hydrogen sulfide. Low-level
concentrations can occur more or less continuously in certain industries,
such as in viscose rayon and pulp production, at oil refineries and in geothermal
energy installations.

In geothermal areas there is a risk of exposure to hydrogen sulfide for the
general population (2). The biodegradation of industrial wastes has been
reported to cause ill effects in the general population (2). An accidental
release of hydrogen sulfide into the air surrounding industrial facilities can
cause very severe effects, as at Poza Rica, Mexico, where 320 people were
hospitalized and 22 died (2). The occurrence of low-level concentrations of
hydrogen sulfide around certain industrial installations is a well known fact.

Health risk evaluation
The first noticeable effect of hydrogen sulfide at low concentrations is its
unpleasant odour. Conjunctival irritation is the next subjective symptom
and can cause so-called “gas eye” at hydrogen sulfide concentrations of 70–
140 mg/m3. Table 16 shows the established dose–effect relationships for
hydrogen sulfide.

The hazards caused by high concentrations of hydrogen sulfide are relatively
well known, but information on human exposure to very low concentrations
is scanty. Workers exposed to hydrogen sulfide concentrations
of less than 30 mg/m3 are reported to have rather diffuse neurological and
mental symptoms (4) and to show no statistically significant differences
when compared with a control group. On the other hand, changes in haem
synthesis have been reported at hydrogen sulfide concentrations of less than
7.8 mg/m3 (1.5–3 mg/m3 average) (5). It is not known whether the inhibition
is caused by the low concentrations or by the cumulative effects of
occasional peak concentrations. Most probably, at concentrations below
1.5 mg/m3 (1 ppm), even with exposure for longer periods, there are very
few detectable health hazards in the toxicological sense. The malodorous

property of hydrogen sulfide is a source of annoyance for a large proportion
of the general population at concentrations below 1.5 mg/m3, but from the
existing data it cannot be concluded whether any health effects result. The
need for epidemiological studies on possible effects of long-term, low-level
hydrogen sulfide exposure is obvious. A satisfactory biological exposure
indicator is also needed.

The full text excerpt of the chapter on Hydrogen Sulfide can be read here:  AQG2ndEd_6_6Hydrogensulfide.
The full document can be read online:  http://www.euro.who.int/__data/assets/pdf_file/0005/74732/E71922.pdf.

2011: TOP 10 STORIES

 

Protesters rally in July against plans for a sulfur melting facility at the N.C. Port of Morehead City. (Dylan Ray photo)

NEWS-TIMES
Published: Sunday, January 1, 2012 2:05 AM EST

One of the most controversial stories of 2011 was PCS Phosphate Co.’s plan to construct a facility to offload, store and melt solid formed sulfur at the state port here.

The project, more than a year in the works, was kept mostly secret until Coastal Area Management Act notifications sent to adjacent properties owners became public in early July. Within days, a grassroots effort was organized and, following Gov. Bev Perdue’s intervention around the end of July, the plan was scuttled.

Gov. Perdue, during a visit to the N.C. Port of Morehead City, signed an executive order mandating that all future port development plans be studied to ensure compatibility with the surrounding community. The order broadened the scope of a state study of maritime industry logistics that had begun in May.

That study is scheduled to be completed in February. Until then all port development plans are effectively on hold. But PCS is still considering its options for meetings its sulfur needs.

The secrecy of the project was maintained ostensibly to qualify it for a state Commerce Department incentive grant program called the One North Carolina Fund. That program mandates “no public discussion” of qualifying projects until an official announcement is made by the state. But many opponents and others not opposed to the plan said the secrecy was mainly to head off potential controversy seen in past port development proposals while the environmental permitting process was under way.

PCS, which operates a phosphate mine in Aurora, is the port’s largest customer, accounting for nearly 1 million tons per year or 86 percent of the Morehead City port’s total tonnage in 2010.

PCS has handled liquid sulfur at the port for decades without incident. But the global market for liquid sulfur has changed and because it is needed for the Aurora mine’s processing operations, the company seeks a new way to supply the material.

A solid sulfur handling facility is still being considered for the Morehead City port, but the Clean County Coalition, the group formed to fight the melting facility, has said it opposes any handling of solid sulfur at the port.

Meanwhile, port officials and members of the Morehead City Port Committee, a nonprofit group of individuals interested in port business, have reached out in an effort to soften the opposition. The group hosted a tour of port facilities during the fall for members of the Morehead City Planning Board, which is in the midst of a review and rewrite of port and industrial uses allowed in the city’s zoning ordinance.

And the state’s maritime strategy study has indicated that port development prospects for Morehead City and Radio Island could include new facilities for containerized cargo operations or a grain and soybean facility. But such facilities are also being studied for other State Ports Authority properties in New Hanover and Brunswick counties.

From Website:  http://www.carolinacoastonline.com/articles/2012/01/01/news-times/news/doc4eff4490c707f663754085.txt

PDF file:  2012-01-01 Carteret County News Times 2011 Top 10 Stories

Sulfur is a chemical element that is nonmetallic. It has a pale yellow color and has no odor. Sulfur in gaseous form combines with oxygen to form sulfur oxide. Sulfur is used to make fertilizer and various types of disinfectant. It is also used in medical laboratories to test skin disease. Sulfur is, however, a hazardous element that should be handled with care.

Health Hazards
Sulfur in a gaseous state mixes with oxygen to form sulfur dioxide, which is hazardous. Inhalation of sulfur fumes causes irritation of the eyes, nose and respiratory track, which leads to headaches, dizziness and nausea. High levels of sulfur can burn the skin, and it can also cause pulmonary edema, a condition in which the lungs are filled up with fluids. Inhaling sulfur may also cause coughing, sneezing or labored breathing.

Fire Hazard
Fine dust of sulfur dispersed in the air is a potential hazard. When sulfur dust mixes with oxygen, it forms sulfur dioxide, which when ignited causes explosion. Dust suspended in air is readily ignited by fumes or static electricity and can cause destructive fires. Fires caused by sulfur are hard to put out because once they spread the presence of oxygen only serves to increase the fire.

Corrosive Hazard
Sulfur is stable and nonreactive when dry, but it is very reactive when it comes into contact with moisture. This makes it react readily with metals and many oxidizing and reducing agents when in the presence of moisture. In the presence of moisture and oxygen, it becomes sulfur dioxide, which forms an acidic and corrosive solution and thus causes corroding of metals.

Environmental Hazard
When sulfur dust comes into contact with oxygen to become sulfur dioxide, it has serious environmental hazards. It affects the living organisms around the area. Sulfur causes vascular damage in veins of the brain, the heart and the kidney. Sulfur can also cause damage to the internal enzyme systems of animals.

References

• Lentech: Sulphur
• MECS Global: Sulfur Handling Hazards
• INCHEM: Sulfur

by Stuart A. Batterman,*,1 Eugene Cairncross,- and Yu-Li Huang*

* Environmental and Industrial Health, University of Michigan, 109 Observatory Drive, Ann Arbor, Michigan 48109; and- Department of Physical Science, Peninsula Technikon, Box 1906, Bellville 7535, Western Cape, South Africa

Received August 28, 1998

A massive fire at a sulfur stockpile in the Western Cape Province of South Africa in December 1995 is estimated to have released over 14,000 t of sulfur dioxide (SO2) over a 20-h period. High and persistent winds greatly reduced the effectiveness of fire-fighting activities and increased the severity of impacts. Nearby urban and agricultural areas were seriously affected. Thousands of people were evacuated from the nearby town of Macassar located 2.5+4 km downwind, and at least several deaths occurred.  Agricultural impacts ranged over a broad area extending to 30 km from the fire site and included severe damage to plants and some animal deaths.

This paper describes the chronology of the fire, the emergency responses, and the immediate impacts. SO2 concentrations are estimated using dispersion modeling, and predictions are evaluated using available monitoring information. Sensitivity analyses are used to test unknown or uncertain model parameters. The SO2 concentrations estimated in Macassar reached extremely dangerous levels, at times over the IDLH level (100 ppm). Predictions agree with the available but very limited monitoring data, as well as with the symptomologyof Macassar residents and plant damage patterns.  Procedures to deal with the limited information and variability in this fire and similar incidents are suggested. The fire is a tragic demonstration of shortcomings in hazardous material management and emergency response.

( 1999 Academic PressKey Words: air pollution; dispersion modeling;emergency response; exposure; hazardous materials;inhalation; Are; respiratory system; sulfur dioxide.

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To the Editor:

….

Clean County Coalition has developed a website that functions as a clearinghouse for information. We will post all pertinent public interest documents relating to projects in ourcounty that could affect the health and/or safety of the citizens and our environment.

….

Anyone wishing to post information about this or any other Carteret County project should feel free to contact us. We will review the documents and if we feel they are appropriate we will place them on our website. We may be reached at: cleancountycoalition@gmail.com.

….

Leigh Johnson
Clean County Coalition VP

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One week later, on January 14, 2011 Town Manager Randy Martin, Mayor Jones, City Planning Director Linda Staab, and Councilman George Ballou attended the Local Emergency Planning Committee meeting. Mayor Jones mentioned this meeting in his timeline (but failed to state that he was present at this meeting).  There was discussion at this meeting of PCS’ plans to melt sulfur at the MHC port. Mayor Jones promised to, “Put the port facilities on our agenda for our next meeting to get an update.”

On May 20, 2011, Morehead City sent a letter to Brad Newland of the NC Division of Air Quality confirming that the PCS melting facility was a permitted use in the Industrial Port (IP) district. The letter mentions “melting solid sulfur to form liquid, then transferring liquid sulfur from the port to barges for transport to Aurora”.  Morehead City Planning Director Linda Staab signed this letter.

In his timeline, Mayor Jones stated that on June 8, 2011, he and EDC Director Miles Stempin discussed the proposed sulfur melting facility which would receive incentives from the Dept. of Commerce. After this, a month passed with no public discussion, public hearing or public notification.

One month later, on July 8, 2011, the Carteret County New Times ran a front page story on the proposed PCS sulfur melting facility. Jet Matthews, owner of Morehead City Yacht Basin, had received a certified letter from PCS notifying him of the PCS CAMA permit application. This was the only permit notification required under state law. After digging, he found out the true scope of the project and went to the paper with the story.

On July 11, 2011, Mayor Richard Stanley of Beaufort signs a resolution opposing the Sulfur melting facility. Mayor Jones went on record opposing the facility on JULY 12.

On JULY 12, 2011, 122 citizens attended a Morehead City Council meeting to voice their anger, dismay, frustration, and shock over the facility and the lack of public notification. And as they say, the rest is history.  Gov. Perdue made her announcement on Wed. July 27.

The ECC project description given to MHC, minutes from the Local services Planning Committee meeting, the MHC Zoning Determination Letter, and the Town of Beaufort resolution (documents referenced above) can all be seen in their original form using the links below.

Referenced Documents:

2011-01-07 Eastern Carolina Council – NC Intergovernmental Review Process Review and Comment Form

2011-01-14 Minutes – Carteret County Local Emergency Planning Committee

2011-05-20 Linda Staab Letter to NC Division of Air Quality

2011-07-11 Beaufort Resolution Against Sulfur Faciility

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Safety in handling sulphur, whether as a solid or liquid, requires recognition of and adequate precautions against three possible dangers:

• Sulphur is a flammable substance and its vapours and dust may be explosive
• Sulphur in its molten state is a burn hazard
• Sulphur may generate hazardous amounts of hydrogen sulphide gas (H₂S)

Flammability

If ignited by spark or flame, sulphur will burn in air, yielding acrid fumes of sulphur dioxide (SO₂). Various investigators have reported spontaneous ignition temperatures for molten pure sulphur in still air which vary from 232°C to 260°C (450°F to 500°F). The flash point of pure sulphur, as determined by the modified Cleveland open cup method and others, has been reported by various investigators at values from 188°C to 207°C (370°F to 405°F). It is agreed that the presence of hydrocarbon impurities in the sulphur will decrease these reported values. The minimum reported value for the flash point of dark crude sulphur is 168°C (335°F).

Sulphur dust suspended in air is readily ignited by flame, static electricity or friction spark. The dust is characterized by a very low ignition point of 190°C (374°F) compared to other combustible dusts. Dust containing 25% or more elemental sulphur may be almost explosive as pure sulphur. Explosive mixtures can also be formed if sulphur is contaminated with chlorides, nitrates or other oxidizing agents. Sulphur is an excellent electrical insulator and under the right conditions will readily pick up static electricity which if discharged can be a source of ignition. The use of spark resistant tools and nonferrous conveyor parts is recommended to minimize sparks when handling solid sulphur.

Where there is a potential for dust to accumulate or be generated the area must be designated with the appropriate hazardous area classification. Electrical equipment in this area must be suitable for the hazardous area classification.

Fire Fighting

If a fire occurs in a closed tank or pit containing molten sulphur it can be extinguished by closing all vents and air inlets. However, the tank or pit may become very hot before the fire is extinguished. A more effective way to extinguish a fire is to use steam. ‘Snuffing’ steam is admitted to the vapour space of the tank and displaces the oxygen in the tank thus starving the fire of oxygen. The system must be properly engineered to ensure steam is distributed thoughout the vapour space.

Small fires in melting pits can often be extinuguished by splashing liquid sulphur to smother the fire.

Spraying water onto the fire may cause the generation of a large amount of steam as the water hits the surface of the hot sulphur. The sudden generation of steam in an enclosed space may result in overpressurization of the tank.

If a fire occurs in a bulk solid sulphur storage pile or hopper, a fine spray or fog of water is the most satisfactory fire extinguishing agent.

As a safety precaution, it is recommended that a water line with hose and fog nozzle should be located where it can be used to extinguish fires in the sulphur storage and melting areas.

Carbon dioxide fire extinguishers can also be employed in fighting sulphur fires.

Burn Hazard

Molten sulphur is typically maintained at a temperature of 140°C (284°F) so improper handling of molten sulphur may result in burns to personnel. First degree burns can result from splashes of liquid sulphur on skin or clothing. The sulphur will quickly solidify but it should not be removed. The affected area should be immerse in cold water for at least 20 minutes and the patient treated for shock. Medical attention should be obtained immediately.

Hydrogen Sulphide

Most of the world’s sulphur is produced from the treatment of sour gases found in refinery and natural gas plants. When solid sulphur is melted, a small amount of hydrogen sulphide gas may be released. Hydrogen sulphide is a toxic, as well as flammable gas.

Respiratory Protection

Sulphur is essentially non-toxic but dust respirators should be worn for the comfort of workers. In case of emergencies, breathing apparatus suitable for sulphur dioxide should be available in the area. Sulphur dioxide will be produced during a sulphur fire.

Eye/Face Protection

In areas where solid sulphur is being handled, dust tight goggles should be worn. In areas where molten sulphur is present, safety glasses with side shields should be worn. A face shield may also be necessary.

Protective Clothing

The use of fire-retardant clothing is recommended. Clothing should be kept clean and free of dust. Heat resistant gloves should be worn in molten sulphur areas.

Source: http://www.sulphuric-acid.com/techmanual/Plant_Safety/safety_sulphur.htm

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