Hydrogen sulfide exposure at a waste treatment facility

Occupational Safety and Health Administration (OSHA) regulations require employers to report workplace-related fatalities.((1)) OSHA inspection policy and procedures require that a workplace fatality or workplace hazards with potential imminent danger receive the highest priority for inspection.((2)) This inspection began on a Saturday when a local fire department advised the OSHA area office of a workplace fatality. The fire department also reported that the death was due to natural causes, based on a county coroner's report that stated the worker had died from a heart attack. Under normal circumstances OSHA begins a workplace fatality investigation within one day of notification. Workplace deaths due to natural causes, as was initially reported in this case, may not receive an OSHA inspection. However, subsequent to the incident, a family member contacted the OSHA area office and reported that the death may have been due to chemical vapor exposures, based on information from co-workers of the deceased. The family had already requested a toxicological screening of the victim and the coroner had agreed. Based on this new information, the local OSHA area office opened a facility inspection.

Neurologic sequela of hydrogen sulfide poisoning

A 25-year-old man, a field operator in a petroleum refinery was found unconscious. He was exposed to hydrogen sulfide and presented with Glasgow Coma Score of 5, severe hypoxemia on arterial blood gas analysis, normal chest radiography, and normal blood pressure. On hospital day 7, his mental state became clear, and neurologic examination showed quadriparesis, profound spasticity, increased tendon reflexes, abnormal Babinski response, and bradykinesia. He was also found to have decreased memory, attention deficits and blunted affect, which suggested general cognitive dysfunction, but which improved soon. MRI scan showed abnormal signals in both basal ganglia and motor cortex, compatible with clinical findings of motor dysfunction.

[Pathomorphological changes of the macroglia in chronic intoxication produced by gas containing hydrogen sulfide]

Changes in the rat brain macroglia produced by a natural gas from Astrakhan source containing hydrogen sulphide were studied immunocytochemically (glial fibrillar acid protein). Primary response was from oligodendroglia, dose increase followed by reaction from the astroglia.

[Determination of the hemoglobin in poisoned blood by spectrophotometery]

OBJECTIVE

In order to establish a objective method of analysis in the case of sulfured hydrogen poison.

METHODS

The sulfured hemoglobin of the biomaterials(blood) were investigated by the spectrophotometry.

RESULTS

Results showed that sulfured hemoglobin had a specific absorbance peak at 612 nm, it is a linear relationship about the absorbancity to the concentration of sulfured hemoglobin.

CONCLUSION

It is possible to mark the poison degree by the spectrophotometery.

Investigation of health effects of hydrogen sulfide from a geothermal source

Little is known about health effects from chronic exposure to hydrogen sulfide (H2S). The city of Rotorua, New Zealand, is exposed to H2S by virtue of its location over a geothermal field. In this study, the authors classified areas within Rotorua as high-, medium, or low-H2S exposure areas. Using 1993-1996 morbidity data, standardized incidence ratios were calculated for neurological, respiratory, and cardiovascular effects. Poisson regression analysis was used to confirm results. Results showed exposure-response trends, particularly for nervous system diseases, but also for respiratory and cardiovascular diseases. Data on confounders were limited to age, ethnicity, and gender. The H2S exposure assessment had limitations. Assumptions were that recent exposure represented long-term exposure and that an individual's entire exposure was received at home. The results of this study strengthen the suggestion that there are chronic health effects from H2S exposure. Further investigation is warranted.

[Cognitive sequelae of acute hydrogen sulphide poisoning. A case report]

BACKGROUND

Hydrogen Sulphide (H2S) is a highly toxic, colorless gas smelling of rotten eggs. It is used in several industries and is a product of many industrial processes such as oil refining, mining and rayon manufacture. Acute, non fatal H2S intoxication at a concentration of 500 ppm, for few minutes, is followed by brain damage characterised by both immediate and permanent neurobehavioural deficits.

OBJECTIVES

The present study describes the neurobehavioral effects of acute, non-fatal H2S intoxication in a healthy 36-year-old male at the workplace.

METHODS

Three months after the acute poisoning, the subject was examined via a neurological examination, neuropsychological tests (Mini Mental State, Verbal Span Test, Digit Span Test, Bourdon-Wiersma Dot Cancellation Test, Benton Visual Retention Test, Somatognosia, Simple Visual Reaction Time, Simple Acoustic Reaction Time), Nuclear Magnetic Resonance (NMR), and Single Photon Emission Tomography (SPET).

RESULTS

The results showed a reduction of cognitive capabilities, depressive symptoms and personality changes even through the results of neurological examination and neuroimaging techniques were unremarkable.

CONCLUSIONS

Neuropsychological testing is a key issue in neurotoxicology assessment, because conventional neurology has been shown to be insensitive to the chemical neurotoxic effects and neuroimaging techniques are often unclear.

Fatal and nonfatal poisoning by hydrogen sulfide at an industrial waste site

An adult man (A) entered a pit to collect seepage at an industrial waste site in Japan. As he suddenly lost consciousness, three colleagues (B, C, D) entered the pit to rescue him. All of these men lost consciousness in the pit. Two workers (A and B) died soon after the accident, one worker (C) died 22 days after the accident, and one worker (D) survived. Since hydrogen sulfide gas was detected in the atmosphere of the pit, gas poisoning was suspected. Toxicological analyses of sulfide and thiosulfate, a metabolite of sulfide, in blood and urine of the victims were made using the extractive alkylation technique combined with gas chromatography/mass spectrometry (GC/MS). Sulfide was detected in the blood of A and B at levels of 0.13 and 0.11 mg/L, respectively, somewhat higher than in healthy persons. Thiosulfate was detected in whole blood of deceased victims A and B, in the plasma of deceased victim C, at concentrations of 10.53, 4.59, and 4.14 mg/L, respectively. These values were similar to those found in fatal cases of hydrogen sulfide poisoning. Thiosulfate was not detected in the plasma of survivor D. With respect to urine samples, thiosulfate was the highest in the non-acute death victim C (137.20 mg/L), followed by that in the survivor D (29.34 mg/L), and low (0.90 mg/L) and not detected in the acute death victims, A and B, respectively. Based on these results, all four patients were victims of hydrogen sulfide poisoning. The concentrations of thiosulfate in blood and urine were more useful than that for sulfide for determining hydrogen sulfide poisoning. Thiosulfate in urine was the only indicator of hydrogen sulfide poisoning in the non-fatal victim.

[Fatal calcium polysulfide overdose presenting corrosive chemical injury of esophagus and sulf-hemoglobinemia]

A-79-year-old woman ingested a cup of unknown violet agricultural solution intentionally. She was vomiting and smelt of sulfur. Arterial blood gas showed metabolic acidosis and marked cyanosis regardless of relatively high PaO2, caused by sulfhemoglobinemia. A nasogastric tube could not be inserted because of marked stenosis caused by endoscopically proven severe corrosive chemical injury (burn) of esophagus. Considering the smell and the clinical presentation, we concluded that the causative agent was calcium polysulfide or lime-sulphur solution, a common agricultural product used as a fungicide. Despite supportive therapy including infusion of NaNO2, the patient expired 4.5 hours after ingestion. Calcium polysulfide ingestions cause direct injury to the upper gastrointestinal tract, and react with gastric HCl producing poisonous H2S gas, which interferes cytochrome oxidase activity, developing tissue hypoxia, shock, and metabolic acidosis. Sulfhemoglobin is also produced causing severe cyanosis.

Belgian coca-cola-related outbreak: intoxication, mass sociogenic illness, or both?

An epidemic of health complaints occurred in five Belgian schools in June 1999. A qualitative investigation described the scenario. The role of soft drinks was assessed by using a case-control study. Cases were students complaining of headache, dizziness, nausea, vomiting, abdominal pain, diarrhea, or trembling. Controls were students present at school on the day of the outbreak but not taken ill. An analysis was performed separately for school A, where the outbreak started, and was pooled for schools B-E. In school A, the attack rate (13.2%) was higher than in schools B-E (3.6%, relative risk = 3.6, 95% confidence interval (CI): 2.5, 5.3). Exclusive consumption of regular Coca-Cola (school A: odds ratio (OR) = 29.7, 95% CI: 1.32, 663.6; schools B-E: OR = 7.3, 95% CI: 2.9, 18.0) and low mental health score (school A: OR = 16.1, 95% CI: 1.3, 201.9; schools B-E: OR = 3.1, 95% CI: 1.5, 6.6) were independently associated with the illness. In schools B-E, consumption of Fanta, consumption of Coca-Cola light, and female gender were also associated with the illness. It seems reasonable to attribute the first cases of illness in school A to regular Coca-Cola consumption. However, mass sociogenic illness could explain the majority of the other cases.

A fatality caused by accidental production of hydrogen sulfide

A 55-year-old male Caucasian truck driver was dead at the scene after breathing hydrogen sulfide (H(2)S) produced by an accidental transfer of sodium hydrogen sulfide (NaHS) from a tanker truck to a tank containing 4% sulfuric acid (H(2)SO(4)) and iron(II) sulfate (FeSO(4)). Autopsy of the decedent's body revealed pulmonary edema and passive congestion in lungs, spleen, kidneys, and adrenal glands. Postmortem biological samples were analyzed for carbon monoxide, cyanide, ethanol, and drugs. Since a potential exposure to H(2)S was involved, blood was also analyzed for sulfide (S(2-)). The analysis entailed isolating S(2-) from blood as H(2)S using 0.5M H(3)PO(4), trapping the gas in 0.1M NaOH, and determining the electromotive force using a sulfide ion specific electrode. Acetaminophen at a concentration of 14.3 microg/ml was found in blood, and metoprolol was detected in the blood, liver, and kidney samples. The blood S(2-) level was determined to be 1.68 microg/ml. It is concluded that the cause of death was H(2)S poisoning associated with a hazardous material accident in an industrial situation.

Noxious gas exposure in the outback: two cases of hydrogen sulfide toxicity

Two cases of toxicity from industrial exposure to hydrogen sulfide are presented. Both patients had neurological effects with loss of consciousness and amnesia along with respiratory symptoms and signs. Both were treated with hyperbaric oxygen therapy in addition to standard resuscitative techniques with rapid improvement. Sodium nitrite and hyperbaric oxygen therapy are suggested specific treatments. The literature and the two case reports support the use of hyperbaric oxygen therapy in the treatment of acute hydrogen sulfide toxicity. Hyperbaric oxygen therapy has also been reported to have a role in the prevention of both short- and long-term neurological toxicity.

[Acute poisoning of pigs with hydrogen sulfide as a result of acidification of slurry on a pig farm]

On a fattening pig farm all 582 animals died of peracute intoxication with hydrogen sulphide (H2S). The accident took place after 6000 litres of lactic acid (41.5 mass %) was dumped in the slurry pit. The volume of released gas was about 575 m3. This resulted in sudden spreading by high pressure of a lethal concentration of hydrogen sulphide to all compartments of the pig house. Analysis of the situation indicated that the level of hydrogen sulphide was 7870 ppm.

Twenty-foot fall averts fatality from massive hydrogen sulfide exposure

Hydrogen sulfide is a colorless irritant and asphyxiant gas with a noxious odor of "rotten eggs." Acute hydrogen sulfide exposure may cause, depending on the level and duration of toxicity, symptoms ranging from mild mucous membrane irritation to permanent neurologic impairment and cardiopulmonary arrest. We present a case of an oil refinery worker exposed to a typically fatal concentration of hydrogen sulfide gas (>1000 ppm) while working on top of a 20-foot ladder. The "knockdown" effect of exposure to high concentrations of hydrogen sulfide caused him to lose consciousness and fall from the top of the ladder. He was transported to the Emergency Department as a major trauma victim. Ironically, this 20-foot fall saved his life and possibly those of the rescuers by immediately removing him from the source of the hydrogen sulfide. Treatment of hazardous materials incidents and the pathophysiology and treatment options for hydrogen sulfide poisoning are discussed.

Acute pit gas (hydrogen sulfide) poisoning in confinement cattle

Rapid deaths in confinement cattle caused by exposure to hydrogen sulfide (H2S) gas from manure pits has not been reported in the USA. In 1997, 158 cattle in 2 confinement pens were exposed to H2S gas as the manure in the pits under a slatted floor was agitated prior to pumping. Approximately 35 of the cattle were lying on the floor when the upper agitator was turned on. Within 5 minutes, many these cattle were down on their sides and paddling. Of these, 26 died within a few minutes. The survivors were treated and sent to slaughter. Cattle that did not show immediate signs of toxicosis remained clinically unaffected. Two steers that were near death were brought to the Purdue Animal Disease Diagnostic Laboratory for clinical evaluation, euthanasia, and necropsy. They were recumbent and unresponsive to visual and auditory stimuli. Necropsy examination yielded no significant gross lesions. No evidence of viral or bacterial infection was found. Ocular fluid nitrate concentrations were within normal limits, and no lead was detected in either animal. Microscopic examination revealed lesions consistent with H2S-induced central nervous system anoxia. Histologically, sections of brain demonstrated massive, diffuse cerebral cortical laminar necrosis and edema. Portions of the outer lamina contained hypereosinophilic and shrunken neurons. The subcortical white matter was vacuolated in some areas. The history, clinical signs, and histologic lesion of cerebral laminar necrosis led to a diagnosis of H2S toxicosis in these cattle.

Is a reduction in residual volume a sub-clinical manifestation of hydrogen sulfide intoxication?

BACKGROUND

A number of employees at an aircraft factory were accidentally exposed to hydrogen sulfide. Because of concern that this may have resulted in lung injury, forty-seven workers were referred for clinical and physiological evaluation.

METHODS

Comprehensive pulmonary function tests were performed including spirometry, flow volume curves, static lung volumes, and diffusion capacity for carbon monoxide.

RESULTS

The results obtained indicated that ten people (23%) had an isolated reduction in residual volume. This was an unexpected finding as other physiological indices of lung function were within normal limits. Clinical examination was also normal, therefore, radiological investigations were considered inappropriate.

CONCLUSIONS

It is suggested that the decrement in residual volume, in the presence of other normal indices of lung function, could represent a sub-acute manifestation of hydrogen sulfide intoxication.

Hydrogen sulfide poisoning: clarification of some controversial issues

BACKGROUND

Hydrogen sulfide is a toxic gas about which much has been written. We discuss here several issues we believe would benefit from further clarification.

CONCLUSIONS

We conclude that: 1) Certain neurotoxic effects of exposure are probably due to a direct toxic effect on the brain, while others are almost certainly a result of hypoxia secondary to H2S-induced respiratory insufficiency; 2) pulmonary edema is a common consequence of poisoning and there is suggestive evidence of hyperactive airway responses in some individuals following brief H2S-induced unconsciousness (knockdown); 3) criteria for acceptable community levels are very different than those governing occupational standards; 4) urinary thiosulfate determinations can be useful for monitoring occupational exposure; and 5) determination of sulfide ion concentrations in blood or major organs can be useful in corroborating a diagnosis of fatal H2S toxicity, but there are many pitfalls in collecting, storing, and analyzing tissue and fluid samples.

[Analysis of 25 episodes of acute occupational poisoning accidents and studies on its preventive strategy]

OBJECTIVE

To study the causes of the occurrence of severe acute occupational poisoning and its first-aid, and to improve its prevention and management.

METHODS

Data of labor health conditions in 25 episodes of poisoning during the past 13 years were collected and analyzed statistically according to industries, enterprises and toxicals.

RESULTS

Twenty-five episodes of poisoning accidents involved 131 persons, with 22 deaths. The incidence rate of occupational poisoning accidents in township and town enterprises exceeded that in state-owned ones. Ten kinds of toxicants were involved in the poisoning, with the hydrogen sulfide, benzene, carbon monoxide, phosgene and organophosphorus pesticide at the top five places in the number of cases with poisoning they caused. There were another 131 persons intoxicated during their emergency action and eight deaths, with a higher incidence and mortality rates due to poisoning than those in the operation workers.

CONCLUSION

The major causes of the poisoning accidents were lack of knowledge of prevention and protection from them. It laid a good foundation for the establishment of emergency rescuing system in the grassroots.

A fatal case of hydrogen sulfide poisoning in a geothermal power plant

An adult man entered an oil separator room to remove waste oil from a vacuum pump in a geothermal power plant. He suddenly collapsed and died soon after. Since hydrogen sulfide gas was detected in the atmosphere at the scene of the accident, poisoning by this gas was suspected and toxicological analysis of sulfide and thiosulfate in blood, brain, lung, femoral muscle was made using the extractive alkylation technique combined with gas chromatography/mass spectrometry (GC/MS). The concentrations of sulfide in these tissues were similar to those previously reported for fatal cases of hydrogen sulfide gas. The concentration of thiosulfate in the blood was at least 48 times higher than the level in control samples. Based on these results, the cause of death was attributed to hydrogen sulfide gas poisoning.

Persistent cognitive and motor deficits following acute hydrogen sulphide poisoning

This case study describes the long-term after-effects of hydrogen sulphide exposure in a previously health 27-year-old male. Upon hospital admission the patient had a Glasgow Coma Score (CGS) of 3; with emergency treatment including hyperbaric oxygen treatments, he progressed to a GCS of 15 on day 7. Although both CT and MRI scans were unremarkable, PET using F-18 deoxyglucose administered 3 years after the accident showed abnormally decreased metabolism bilaterally in the temporal and inferior parietal lobes as well as the left thalamus. Uptake in the striatum was heterogeneous and abnormal. A cerebral perfusion study using SPECT performed 3.5 years after the accident revealed bilaterally decreased flow in the putamen but no cortical abnormalities. Neuropsychological and neurofunctional testing revealed the following impairments: microsmia, psychomotor slowing, extrapyramidal signs and deficits in memory and executive/planning functioning. These findings are discussed in the context of hydrogen sulphide's known mechanisms of toxicity and the functions of the basal ganglia.

Occupational neurotoxic diseases in Taiwan: a review of the outbreaks and clinical features

In the past 20 years, several outbreaks of neurotoxic disease due to occupational exposure have occurred in Taiwan. The most notorious outbreaks were 'Yu-cheng' due to contamination of polychlorinated biphenyls in cooking oil, lead poisoning in battery manufacturers and workers in a ship-scrapping yard, tile factory and battery recycling plants, and n-Hexane intoxication in press-proffers and ball-manufacturers. In addition, there were manganese intoxication in ferromanganese smelters, mercury intoxication in lamp-socket workers, carbon disulfide intoxication in viscose rayon workers and hydrogen sulfide intoxication in chemical synthetic plants. Although the incidence of occupational neurotoxic diseases has increased, the real incidence is probably still underestimated. The reasons for the underestimation include: 1) the education for workers in industrial hygiene is inadequate; 2) high risk workers are not screened well; 3) physicians are not well trained in early diagnosis of occupational diseases; 4) material safety data information is not readily available in the factories; and 5) the threshold limit values for toxic substances are relatively high in Taiwan, compared with other developed countries.

Hydrogen sulfide poisoning: an antidotal role for sodium nitrite?

In 2 separate incidents, 6 patients were poisoned with hydrogen sulfide (H2S) in sewer gas. In the first incident, mixing acid- and sodium hydroxide-based drain cleaners in a confined space resulted in 4 poisonings and 2 deaths. Three would-be rescuers were seriously poisoned and 1 died. Two survivors had neurological sequelae. Sodium nitrite appeared to have some clinical efficacy in 1 case. The second incident involved 2 patients working on a pump in a sewage pond. A patient lying on a raft close to the pond surface was seriously poisoned; sodium nitrite was clinically efficacious and this patient survived without developing neurological sequelae. Sodium nitrite deserves further clinical study as a potential H2S antidote.