Exposure to hydrogen sulphide and respiratory function.

A study was carried out to assess possible effects of low concentrations of hydrogen sulphide on respiratory function. The cohort comprised 26 male pulp mill workers (mean age 40.3, range 22-60 years) with a daily exposure to hydrogen sulphide in the workplace, and 10 volunteers, who had asthma (three men, mean age 40.7, range 33 to 50 years, and seven women, mean age 44.1, range 31 to 61 years). The respiratory function of the pulp mill workers was monitored by measuring forced vital capacity (FVC), forced expiratory volume in one second (FEV1), and bronchial responsiveness after at least one day off work and at the end of a workday. Bronchial responsiveness was tested by challenge with histamine. The 10 asthmatic subjects were exposed in laboratory conditions to 2 ppm of hydrogen sulphide for 30 minutes in an exposure chamber. Airway resistance (Raw) and specific airway conductance (SGaw) were assessed by a body plethysmograph, and the ventilatory capacities were measured with a flow volume spirometer. No significant changes in respiratory function or bronchial responsiveness related to exposure to hydrogen sulphide in the pulp mill workers were found. In the asthmatic subjects, Raw was increased by 26.3% and SGaw was decreased by 8.4% on average after exposure to hydrogen sulphide. These changes were not statistically significant. In two subjects, however, changes were greater than 30% in both Raw and SGaw, indicating bronchial obstruction. It is concluded that exposure for a relatively short time to hydrogen sulphide concentrations appreciably higher than those existing in ambient air do not cause noticeable effects on respiratory function.     

Exposure to bioaerosols: allergic reactions and respiratory function in Polish hop growers

BACKGROUND: The aim of the study was to assess the prevalence of work-related symptoms in hop growers and their relation to bioaerosols exposure. The study group comprised 69 hop growers and 58 office workers as controls. The examination included: physician-administrated questionnaire, PEF measurements, skin prick test, agar-gel precipitation test, and migration inhibition test. Microbiological air sampling was performed on all farms. RESULTS: The concentrations of total airborne microflora ranged from 2.08 to 129.6 x 10(3) CFU/m3. Airborne endotoxin and dust concentrations ranged from 26 to 6250 ng/m3 and 0.2-31.7 mg/m3, respectively. Altogether 52.2% of farmers complained of work-related symptoms. Positive skin reactions to microbial allergens were significantly more frequent in a group of hop growers with work-related respiratory symptoms compared to the rest of the farmers (18% vs 2%, P <0.05). Positive reactions in agar-gel precipitation test and in the leukocyte migration inhibition test were not correlated with the occurrence of work-related symptoms. The mean daily PEF values in farmers were lower compared to controls (469.7 +/- 127.5 vs 562.9 +/- 123.8; P <0.001). PEF (amp%mean) was higher in farmers compared to controls (9.3% vs 8.1%; P <0.05). CONCLUSION: Despite relatively lower exposure to bioaerosols, compared to farmers in other branches of agriculture, over 50% of hop growers complained of work-related symptoms. This may be partly due to the effects of microbial allergens and toxins and partly to the irritant or allergic properties of hop plant itself.     

Exposure to oxides of nitrogen: respiratory symptoms and lung function in British coalminers

Five hundred and sixty British coalminers with relatively high or relatively low exposures to oxides of nitrogen, based on measurements of concentrations of these gases at nine collieries over four years, and records of the men's places of work and colliery mining conditions over a total of eight years have been studied. Data on these men's respiratory symptoms and ventilatory capacity (FEV1), obtained as part of an epidemiological study of British coalminers, have been used to investigate possible adverse effects of exposure to oxides of nitrogen. Exposures to oxides of nitrogen were generally well below threshold limit values, though occasional peaks after shotfiring and during diesel locomotive use did exceed short term limits. No relationship was found between exposure and respiratory symptoms or decline in FEV1 nor was there any evidence of differences in symptoms of FEV1 between 44 pairs of men matched for age, dust exposure, smoking habit, coal rank, and type of work, but differing in respect of exposure to oxides of nitrogen. It has not been possible to detect any adverse effects on the health of this working population of the levels of nitrogen oxides that have occurred in British mines over the past decade. With the current levels of these gases, any long term effects on respiratory health are so small as to be undetectable in the presence of smoking and dust exposure.     

Exposure to oxides of nitrogen: respiratory symptoms and lung function in British coalminers.

Five hundred and sixty British coalminers with relatively high or relatively low exposures to oxides of nitrogen, based on measurements of concentrations of these gases at nine collieries over four years, and records of the men's places of work and colliery mining conditions over a total of eight years have been studied. Data on these men's respiratory symptoms and ventilatory capacity (FEV1), obtained as part of an epidemiological study of British coalminers, have been used to investigate possible adverse effects of exposure to oxides of nitrogen. Exposures to oxides of nitrogen were generally well below threshold limit values, though occasional peaks after shotfiring and during diesel locomotive use did exceed short term limits. No relationship was found between exposure and respiratory symptoms or decline in FEV1 nor was there any evidence of differences in symptoms of FEV1 between 44 pairs of men matched for age, dust exposure, smoking habit, coal rank, and type of work, but differing in respect of exposure to oxides of nitrogen. It has not been possible to detect any adverse effects on the health of this working population of the levels of nitrogen oxides that have occurred in British mines over the past decade. With the current levels of these gases, any long term effects on respiratory health are so small as to be undetectable in the presence of smoking and dust exposure.     

Exposure to arsenic and respiratory cancer. A reanalysis

This paper is a reanalysis of data on the respiratory cancer mortality experience of 2,802 men who worked one year or more during the period 1940-1964 at a copper smelter in Tacoma, Washington. Exposure estimates presented earlier have been recalculated and perhaps improved. While the previous analysis showed only a weak relation between respiratory cancer and arsenic exposure, use of new data shows a much stronger relation--but one that is concave downward and not ordinarily considered for environmental exposure and cancer. This new analysis indicates that arsenic is probably more potent as a carcinogen than indicated by other studies. It also demonstrates the distinction between airborne arsenic and the bioavailability of arsenic, and the importance of this distinction for risk assessment. When a dose-response relation is based on airborne concentrations of arsenic, it is clearly concave downward, but when based on urine concentrations, it appears to be linear.     

Fatal hydrogen sulphide poisoning in unconfined spaces

Fatal hydrogen sulphide poisoning usually occurs in confined spaces. We report two fatal accidents in unconfined spaces. The first accident caused the death of three workers who entered an unconfined room in a silo of sludge at the same time that a truck dumped several tons of sludge from water purification stations. The hydrogen sulphide that had accumulated inside the silo spilled out into the interior of the room due to a 'splashing effect' caused by the impact of the dumped sludge. The second accident occurred when the foreman of a wastewater treatment plant entered one of the substations to perform routine checks and suddenly lost consciousness. Although he was rapidly transferred to an intensive care unit, death occurred a few hours later. Hydrogen sulphide production was, in this case, due to an 'embolism effect' produced by the displacement of wastewater when the substation pumps were activated. We suggest ways in which accidents such as these caused by sudden release of hydrogen sulphide can be prevented.     

Long-term effects on the olfactory system of exposure to hydrogen sulphide

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.

 

     

An assessment of the exposure of water reclamation workers to hydrogen sulphide

The paper describes a 4-month study of water reclamation workers in a rural area. Workers were chosen randomly from each of three groups: permanent site workers, mobile workers and tanker drivers. The exposure to H2S of each of these workers was monitored with pumped long-term colorimetric tubes over 4 days. The reclamation sites were visited over the period of the study and monitored with a hand-held H2S-measuring instrument to identify sources of possible exposure. Data on the weather conditions were also collected. Routine exposure to H2S was found to be low; only 14% of exposures were above the minimum detection limit of 0.1 ppm 8-h time-weighted average (TWA). None of the 190 valid samples were above the 8-h TWA occupational exposure standard (OES) of 10 ppm. If all the exposure had occurred in a 10 min period, 6% of exposures would have been above the 10 min TWA limit. The hand-held readings and knowledge of the work pattern suggest that this was unlikely to have been the case. Most of the positive personal exposure measurements were associated with tanker drivers who were not dealing with treated sludge only. There was a statistically significant difference between the likelihood of exposure to H2S occurring in warmer, drier weather and in cooler, wetter weather. Sites and jobs which can result in transient exposure to H2S are identified.     

Exposure to styrene and mortality from nonmalignant respiratory diseases.

A cohort of 34,560 men and 6128 women employed in 660 European factories manufacturing reinforced plastic products, followed up originally to assess the risk of cancer, was used to assess the risk of non-malignant respiratory diseases associated with exposure to styrene. Mortality from pneumonia was associated with intensity of exposure to styrene, but this may have been due to chance. Mortality from bronchitis, emphysema, and asthma was not associated with styrene exposure.     

疏通下水道引起硫化氢中毒报告

该文报告三明市某地段在疏通下水道时 ,由于用人单位和民工缺乏对硫化氢气体危害的认识 ,在未佩戴任何防护用品情况下 ,行下水道疏通 ,造成一人死亡 ,二人中毒事故。建议用人单位要加强安全防范意识 ,工人也要加强自我保护意识 ,防止类似事故的发生。     

Exposure to hydrogen peroxide at TLV level does not induce lung function changes: a longitudinal study

This study reports on longitudinal changes in lung function using spirometry of employees at a beverage processing plant, where exposure information (1995-2001) suggests that the threshold limit value (TLV)-Time Weighted Average (TWA) of 1 ppm was not likely exceeded. Changes over time in lung function (Forced Expiratory Volume of 1st second, FEV1; Forced Vital Capacity, FVC; and FEV1/FVC ratio; all expressed as percent of the predicted) were evaluated by using sparse lung function data obtained from 1993 to 2002 in 43 exposed and 31 unexposed workers. The longitudinal changes were assessed using multiple regression analysis where the dependent variable was the annual change of lung function indices and the independent variables were exposure and smoking habits. With regard to exposure, FVC increased, FEV1 was unchanged, and the FEV1/FVC ratio tended to decrease. The latter difference was not significant when FVC was used as a covariate. The FEV1 is significantly worse in smokers than in non-smokers. These data suggest that no lung function changes occur when the H2O2 levels were compliant to the exposure standard. Our findings support the current TLV-TWA of 1 ppm for H2O2.     

Persistent cognitive and motor deficits following acute hydrogen sulphide poisoning

This case study describes the long-term after-effects of hydrogensulphide exposure in a previously healthy 27-year-old male.Upon hospital admission the patient had a Glasgow Coma Score(CGS) of 3; with emergency treatment including hyperbaric oxygentreatments, he progressed to a GCS of 15 on day 7. Althoughboth CT and MRI scans were unremarkable, PET using F-18 deoxyglucoseadministered 3 years after the accident showed abnormally decreasedmetabolism bilaterally in the temporal and inferior parietallobes as well as the left thalamus. Uptake in the striatum washeterogeneous and abnormal. A cerebral perfusion study usingSPECT performed 3.5 years after the accident revealed bilaterallydecreased flow in the putamen but no cortical abnormalities.Neuropsychological and neurofunctional testing revealed thefollowing impairments: microsmia, psychomotor slowing, extrapyramidalsigns and deficits in memory and executive/planning functioning.These findings are discussed in the context of hydrogen suiphide'sknown mechanisms of toxicity and the functions of the basalganglia.     

Exposure to mineral oil mist and respiratory symptoms in marine engineers

The purpose of the study was to see if marine engineers have an increased prevalence of respiratory symptoms, and if so whether it can be related to occupational exposures. A self-administered questionnaire was sent to 700 male seamen from three Norwegian ferry companies. Of the 492 respondents, 169 were currently working as marine engineers and 295 had never worked as marine engineers. The outcomes of cough and wheezing, chronic bronchitis, severe dyspnea, any dyspnea, and mucous membrane irritation (MMI) were defined from the questionnaire. Age and smoking-adjusted prevalences of these respiratory conditions were compared between the groups. Logistic regression was used to further elucidate the explanatory variables. The exposure assessment indicated an exposure (TWAC) to oil mist for marine engineers in the range from 0.12 to 0.74 mg/m³ (mean 0.45 mg/m³). When comparing current marine engineers with those who had never worked as marine engineers, the prevalence ratios were 1.38 (95% CI 1.0–1.9) for MMI, 1.53 (95% CI 1.2–1.9) for any dyspnea, and 1.63 (95% CI 1.0–2.6) for severe dyspnea. The differences remained for some of the symptoms after controlling for self-reported former asbestos exposure in the regression analysis. The increased prevalence of respiratory symptoms found among marine engineers in this investigation may partly be explained by oil-mist exposure, or more probably by a combination of past asbestos exposure and past and present oil-mist exposure. Am. J. Ind. Med. 32:84-89, 1997. © 1997 Wiley-Liss, Inc.     

Exposure to community violence and upper respiratory illness in older adolescents

PurposeTo examine the relationship between exposure to chronic community violence and upper respiratory illness (URI) symptoms among urban adolescents of color; and to test the generality of a model of the relationship between social stress and URI.MethodThe research used a cross-sectional correlational design. The sample was 769 first-semester first-year students in an urban nonresidential 4-year college from the academic years 1999–2002. Data were collected by a group-administered questionnaire in academic classes. The research used three multi-item additive scales (each with high reliability and validity): exposure to community violence, psychological distress, and URI symptoms. Multiple regression procedures were used to analyze the data.ResultsPositive correlations were obtained between: exposure to community violence and reporting of URI (r = .19), exposure and psychological distress (r = .22), and psychological distress and URI (r = .51). The relationship between exposure to community violence and URI is greatly reduced when level of psychological distress is statistically controlled.ConclusionsExposure to community violence is related to experiencing URI symptoms among older urban adolescents of color; the effect size of the relationship is small-medium. Psychological distress mediates the impact of exposure to community violence on URI. The findings expand the range of social stressors that are empirically related to URI, and populations in which a relationship between social stressors and URI may be found.     

Exposure to tremolite asbestos and respiratory health in Swedish dolomite workers

OBJECTIVES—Deposits of carbonate rock like limestone and dolomite may contain tremolite asbestos. This study assessed the exposure to tremolite asbestos and the respiratory health of Swedish dolomite workers.
METHODS—95% of 137 eligible workers at two dolomite producing companies completed a self administered questionnaire that included questions on respiratory symptoms and were examined with spirometry as well as chest radiography. Total exposure to dust was gravimetrically measured and the tremolite asbestos content of the dust was assessed with polarisation and phase contrast microscopy.
RESULTS—Dolomite dust concentrations were moderate (median 2.8 mg/m³) and tremolite asbestos concentrations were generally below the limit of detection (<0.03 fibres/ml). Somewhat higher values, around 0.1 fibres/ml, were obtained in manual stone sorting and bagging. Respiratory symptoms suggestive of chronic bronchitis were more related to smoking than to estimates of individual exposure to dust. The mean vital capacity was 0.2 l lower than expected after adjustment for sex, age, height, and smoking but the decline in lung function was not associated with current or cumulative exposure to dust in a clear cut way. Two definite cases of pleural plaques and one possible case of simple pneumoconiosis were noted, but the plaques could not be attributed exclusively to exposure to tremolite asbestos.
CONCLUSIONS—Dolomite mining and milling may indeed entail low levels of exposure to tremolite asbestos, but this exposure was not a strong determinant of respiratory symptoms, lung function, or pneumoconiosis in exposed Swedish workers. This was true also for dolomite dust. The hazards of exposure to tremolite asbestos may vary across deposits, however, and additional studies at other sites of carbonate rock exploitation are warranted.


Keywords: asbestos tremolite; dolomite; lung function     

Exposure to organochlorine compounds and effects on ovarian function

BACKGROUND: Some chemicals appear to have hormonally active properties in animals, but data in humans are sparse. Therefore, we examined ovarian function in relation to organochlorine compound levels. METHODS: During 1997-1999, 50 Southeast Asian immigrant women of reproductive age collected urine samples daily. These samples were assayed for metabolites of estrogen and progesterone, and the women's menstrual cycle parameters were assessed. Organochlorine compounds (including DDT, its metabolite DDE, and 10 polychlorinated biphenyl [PCB] congeners) were measured in serum. RESULTS: All samples had detectable DDT and DDE, with mean levels higher than typical U.S. populations. Mean cycle length was approximately 4 days shorter at the highest quartile concentration of DDT or DDE compared with the lowest. After adjustment for lipid levels, age, parity, and tubal ligation, and exclusion of a particularly long cycle, the decrements were attenuated to less than 1 day, with wide confidence intervals (CIs). The adjusted mean luteal phase length was shorter by approximately 1.5 days at the highest quartile of DDT (95% CI = -2.6 to -0.30) or DDE (-2.6 to -0.20). With each doubling of the DDE level, cycle length decreased 1.1 day (-2.4 to 0.23) and luteal phase length decreased 0.6 days (-1.1 to -0.2). Progesterone metabolite levels during the luteal phase were consistently decreased with higher DDE concentration. PCB levels were not generally associated with cycle length or hormone parameters after adjustment, and they did not alter the DDE associations when included in the same models. CONCLUSIONS: This study indicates a potential effect of DDE on ovarian function, which may influence other end points such as fertility, pregnancy, and reproductive cancers.     

Exposure to grain dust and changes in lung function

Respiratory symptoms and lung function were assessed in 41 seasonal grain handlers and related to duration of employment and level of exposure to grain dust. Ten public works department employees, not exposed to grain dust, were examined during the same period. Respiratory symptoms, forced expired volume in one second (FEV1), and bronchial responsiveness (dose of methacholine provoking a 20% fall in FEV1-PD20) were assessed before starting work and at weekly intervals during a period of employment lasting up to four weeks. Two atopic grainhandlers with pronounced bronchial hyperresponsiveness (PD20 less than 1 mumol) and a history of asthma withdrew from the study within two weeks because they developed severe asthma. Respiratory symptoms were more frequent and more often attributed to work in the grainhandlers than in the non-exposed subjects. In the grainhandlers the FEV1 decreased by a mean (95% confidence intervals) of 321 ml (198-444) (p less than 0.05) and the mean (95% confidence interval) PD20 decreased from 20.6 mumol (10.3-41.2) to 6.0 mumol (2.8-12.5) (p less than 0.05) after one week of work. Over the next three weeks the mean FEV1 returned towards the prestudy values. The mean PD20, however, remained significantly lower than the initial value. The mean FEV1 and PD20 did not change significantly in the non-exposed subjects. The frequency of symptoms and decreases in FEV1 were greater in grainhandlers when working in jobs where total exposure to dust was greater than 20 mg/m3 than when working in jobs where it was less than 10 mg/m3. The results indicate that occupational exposure to grain dust results in respiratory symptoms and changes in lung function, including increased airway responsiveness, within the first week of exposure to grain dust at work. These changes appear to be determined by the degree of dust exposure and suggest a direct effect of grain dust on the lung in these subjects.     

Exposure to hydrogen sulfide, mercaptans and sulfur dioxide in pulp industry

An hygienic survey for hydrogen sulfide, methyl mercaptan and its derivatives and sulfur dioxide in kraft mills and in sulfite mills revealed concentrations varying from 0 to 20 ppm hydrogen sulfide, 0 to 15 ppm methyl mercaptan and comparable amounts of dimethyl sulfide with dimethyl disulfide up to 1.5 ppm. The greatest emissions were detected at chip chutes and evaporation vacuum pumps. Batch operations yielded clearly higher sulfur dioxide concentrations (up to 20 ppm) as compared to a continuous ammonia-base digester. Furthermore, there was a strong correlation with the season in the sulfite mills where higher concentrations were found in the winter when natural ventilation was poorer. As to the health effects, the exposed workers complained of headaches and a decrease in concentration capacity more often than matched controls. The number of sick leaves was greater in the exposed workers than among the controls.