Preventable exposure to trimethyl tin chloride: a case report

Trimethyl tin chloride (TMTC) is a highly toxic organotin compound that affects four main target organs: the brain, liver, immune system and skin. Exposure can occur by inhalation, ingestion or direct skin absorption. Trimethyl tin is but one of many hazardous substances with potentially serious health consequences to which individuals working in research laboratories may be exposed. We report a preventable case of TMTC exposure. Better understanding of the Canadian Workplace Hazardous Materials Information System (WHMIS) legislation and its applicability to the research laboratory situation would prevent such unnecessary exposure to hazardous substances.     

Metal fume fever presenting as aseptic meningitis with pericarditis, pleuritis and pneumonitis

BACKGROUND: Metal fume fever (MFF) is a well-known complication of zinc oxide fume inhalation. Prompt recognition of this condition is essential for the proper medical management of this self-limited disease. AIM: To present a unique and unusual case of MFF. RESULTS: Our patient is a 25-year-old male welder who had MFF and presented with aseptic meningitis with pericarditis, pleuritis and pneumonitis. To our knowledge, this is the first case of MMF presenting with these signs and symptoms. CONCLUSIONS: MFF can present with a systemic inflammatory response causing a multi-organ serositis. Our case highlights the utmost importance of obtaining an occupational history on all our patients, even if they are critically ill.     

Algae-induced occupational asthma in a thalassotherapist

BACKGROUND: Algae powders have been increasingly used in therapeutic preparations. Their potential as inducers of occupational asthma (OA), however, remains to be demonstrated. METHODS: A 33-year-old woman developed asthma following exposure to algae powder used for thalassotherapy. She had positive patch tests to nickel and cobalt in an evaluation for intermittent skin rash. At work, she had a normal forced expiratory flow in 1 s (FEV(1)) but moderate airway hyperresponsiveness. Bronchial provocation tests (BPT) were obtained. RESULTS: On BPT, an isolated early response was observed after a 1-min inhalation of dry algae powder, with a 50% fall in FEV(1) after exposure; the control BPT with lactose powder was negative. CONCLUSIONS: We report a case of algae-powder-induced OA. Such responses could be due to a sensitization to algae proteins or metal contaminants bioabsorbed by the vegetal particles.     

Occupational asthma and rhinitis caused by 1,2-benzisothiazolin-3-one in a chemical worker

We report a case of occupational asthma and rhinitis causedby inhalation of 1,2-benzisothiazolin-3-one, an additive usedas a microbicidal in detergent production, in a 26-year-oldman employed in a chemical factory producing detergents. Thesubject's task consisted of pouring raw materials into the recipientof a machine which mixed the substances. Two months after thebeginning of this job the patient complained of rhinitis andasthma at the workplace. The specific challenge test with 1,2-benzisothiazolin-3-one,one of the raw materials to which the subject was exposed, provokedan immediate prolonged asthmatic response and nasal symptoms,whereas exposure to other agents (e.g., -amylase, alcalase orbezalkonium chloride) to which the patient was also exposedat work did not. To our knowledge this is the first case ofoccupational asthma and rhinitis caused by this compound.     

Occupational histamine poisoning by fish flour: a case report

Histamine poisoning due to inhalation and skin contact with fish products is rarely described in the literature. This study presents a case of occupational histamine poisoning by spoiled fish flour via inhalation, skin and eye contact. Shipments of fish flour transported in black or blue bags, depending on the source, were handled by 20 harbour workers. Ten workers handling blue bags developed allergy-like skin, eye, gastrointestinal, respiratory and cardiac symptoms within 30 min. Workers handling black bags were symptom-free, except for minimal eye irritation. After consultation with the Poison Control Centre histamine poisoning was suspected. The histamine content, as determined by thin-layer chromatography, was 10-fold higher in samples from the blue than from the black bags (510 mg/100 g flour compared with 50 mg/100 g flour, respectively). Part of the shipment was labelled as hazardous for human health with permission for further usage only under specific personal protective measures. It is suggested that the highest permissible levels of histamine in fish flour and similar products should be set and legally adopted.     

Nanotechnology and the occupational physician

Nanoparticles differ from the same material at larger scale in chemical and physical properties. Evidence from studies of fibres leads to the conclusion that inhalation of nanotubes could be dangerous and should be regulated. Air pollution research has suggested that particles may be more toxic to cells at the nanoscale. At present the marketing of nanoparticles is advancing more rapidly than research into their safety and toxicology, and one serious inhalation episode has been reported in Germany from apparent use of a nanoproduct. This rapidly developing industry will make an impact on the work of occupational physicians, first in universities and small concerns but later more widely. The future safety of workers and consumers is dependent on research into hazard and risk, an area in which the UK and most other countries are dragging their feet. However, a resource, the Safety of Nanomaterials Interdisciplinary Research Consortium, has been established in the UK to assist those active in this field.     

SWORD '97: surveillance of work-related and occupational respiratory disease in the UK

SWORD is one of seven clinically based reporting schemes which together now provide almost comprehensive coverage of occupational diseases across the UK. Although SWORD is now in its tenth year, participation rates remain high. Of an estimated 3,903 new cases seen this year, 1,031 (26%) were of occupational asthma, 978 (25%) of mesothelioma, 794 (20%) of non-malignant pleural disease, 336 (9%) of pneumoconiosis and 233 (6%) of inhalation accidents. Incidence rates of occupational asthma were generally highest among workers in the manufacture of wood products, textiles and food (particularly grain products and crustaceans) and additionally, in the production of precious and non-ferrous metals, rubber goods, detergents and perfumes, and in mining. Health care workers were noted to have a surprisingly high incidence of inhalation accidents. Occupational asthma attributed to latex has increased dramatically; the highest rates are among laboratory technicians, shoe workers and health care workers.     

Challenge testing in the diagnosis of occupational allergic conjunctivitis

BACKGROUND: Providing evidence for the allergic aetiology of ocular symptoms developing as a result of occupational exposure is important for compensation procedures in many countries. AIM: To perform cellular analysis of tear fluid before and after a specific challenge test with high-molecular weight allergens in symptomatic subjects. METHODS: The subjects were 23 bakers with a history of conjunctivitis or rhinoconjunctivitis associated with occupational exposure to wheat flour and positive skin prick test with this allergen. A specific inhalation challenge test with wheat flour and a placebo test were performed. The symptom score (SS) and cellular changes in tear fluid and nasal washings were assessed. RESULTS: Specific provocation test induced significant eosinophil influx in tear fluid in only six patients. No changes in the proportion of other cells could be observed. Cytological changes in tear fluid did not correlate with either ocular SS (Pearson r = 0.18, P = 0.40) or changes in the nasal lavage fluid or SS (Pearson r = 0.13, P = 0.56). However, an analysis of SS results obtained at 30 min and at 24 h after the challenge revealed that cellular changes in tear fluid correlated significantly both with the early and late changes in SS (Pearson r = 0.52, P < 0.05 and Pearson r = 0.81, P < 0.001, respectively). CONCLUSIONS: Analysis of cellular changes in tear fluid during specific inhalation challenge test seems to be a valuable diagnostic tool in occupational ocular allergy. However, the discrepancy between the findings of cellular analysis and SS revealed by the present study requires further research.     

A survey of starch particle counts in the hospital environment in relation to the use of powdered latex gloves

As latex proteins, which cause latex hypersensitivity, can befound on starch particles and inhalation may be a route forsensitization, the presence of starch particles in hospitalair was examined. The starch particles were demonstrated byimmobilization onto cellulose acetate filters and staining withiodine. Rooms in which powdered latex gloves were used gavecounts of up to >3667 particles per cubic meter of air. Starchparticles were not found in the air in rooms where latex gloveswere not used, and were highest in rooms with a high glove usagebut no ventilation. A change to powder-free gloves significantlyreduced the count of starch particles in the unventilated Accident/EmergencyDepartment air. Use of powder-free gloves should be consideredespecially in unventilated areas in healthcare premises.     

SWORD '98: surveillance of work-related and occupational respiratory disease in the UK

The SWORD surveillance scheme, now 10 years old, uses systematic reporting from physicians to provide a picture of the incidence of occupational respiratory disease in the United Kingdom. An estimated total of 2966 incident cases was derived from reports by chest and occupational physicians during the 1998 calendar year. Occupational asthma continues to be the most-reported respiratory condition, with an estimated 822 cases (27% of total cases). The proportion of cases of mesothelioma (23%), benign pleural disease (21%) pneumoconiosis (7%) and inhalation injuries (6%) remain similar to those estimated in past years, although fewer cases overall were reported. The most commonly identified agents causing asthma in 1998 were enzymes, isocyanates, laboratory animals and insects, colophony and fluxes, flour, latex, and glutaraldehyde. An increased incidence of respiratory diseases of short latency was seen in mining, whilst cases in chemical, mineral products and motor vehicle manufacture remained high; lower rates were noted in wood products and textile manufacture when compared with 1997 figures. Inhalation accidents over the past 3 years were reviewed; gaseous agents and combustion products accounted for nearly half of cases. High rates for inhalation injuries were seen in coal miners, fuel production, motor vehicle manufacturing, water purification, and chemical manufacturing.     

Validation of the end-expired method for measuring carboxyhaemoglobin levels for the use in occupational and environmental exposure studies.

Carbon monoxide is one of the most common toxins encountered in work settings, the gas being emitted in situations where there is incomplete combustion of carbon-containing substances. Its acute and chronic health effects have been well-documented. While identification of dangerous situations and evaluation of control measures are conducted by environmental monitoring, the body burden due to inhalation of carbon monoxide is measured by an individual's blood carboxyhaemoglobin level. Carboxyhaemoglobin level can be measured directly from a blood sample or, indirectly, by measuring the end-expired carbon monoxide level and using the charts provided to read the corresponding carboxyhaemoglobin level. As the end-expired method is not an intervention method, and is therefore easy to conduct, it is being used widely in epidemiological studies and it could also be used for individual measurements. This study presents a better statistical method for validating the end-expired method than the correlation method used and described in previous studies.     

Biological monitoring of workers exposed to dimethylformamide in a textile polyurethane unit

Dimethylformamide (DMF) is a universal solvent noted for its solubility in both aqueous and lipid media. It is hepatotoxic, and there are concerns about its carcinogenicity. Our objective was to determine the correlation between air monitoring measurements and biological measurements of a suitable metabolite of DMF in a cohort of operatives in a polyurethane production unit. This was done with a view to assessing how much the inhalation route contributed to total DMF exposure, mainly for control purposes. We investigated the relationship between personal air sample measurements of DMF and biological measurements of N-methylformamide (NMF) in nine adult subjects, recruited across the shifts, with varying levels of exposure to DMF. Personal exposure monitoring was carried out with a low-flow-rate Model 222-4 SKC pump, while post-shift urine samples were obtained for further analysis. Operatives were asked to abstain from consuming alcohol for 24 h before the designated shift, as advised by the laboratory responsible for the analysis of urine samples. We found a very strong statistical association between air sample measurements of DMF and NMF in the urine of the sample population (R(2) = 0.95, P < 0.0001). This study suggests that airborne exposure contributes significantly to elevated levels of NMF and, therefore, indicates that efforts should be concentrated on engineering controls in reducing workplace DMF exposure.     

Air pollution and the heart

Despite legislation, leading to dramatic decreases in levels of air pollution since the time of the great smogs, a large body of epidemiological evidence has demonstrated that pollution continues to have adverse effects on human health. One striking finding from the epidemiological data is that patients with cardiovascular disease are susceptible to acute rises in ambient pollutants. Mortality and hospital admissions for myocardial infarction, congestive cardiac failure and cardiac arrhythmia all increase with a rise in the concentration of both particulate and gaseous pollutants. Before concluding that this association is a causal one, plausible pathophysiological mechanisms are required. Evidence is accumulating in support of two mechanistic hypotheses: inhalation of pollutants might provoke a local inflammatory response with the consequent release into the circulation of pro-thrombotic and inflammatory cytokines. A systemic response of this nature would put individuals with coronary atheroma at increased risk of cardiac events; exposure to pollutants may have an adverse effect on cardiac autonomic control, leading to an increased risk of arrhythmia in susceptible patients. Clarification of the pollutants involved and the precise mechanisms of action is essential in designing measures by which susceptible individuals might be protected from the adverse cardiovascular effects of air pollution.     

Longitudinal medical surveillance showing lack of progression of argyrosis in a silver refiner

Silver is a recognized cause of argyrosis and argyria. This case report describes blood silver levels and longitudinal ophthalmological examination in a previously reported case of argyrosis over a 5-year period.     

Unexpected cause of raised benzene absorption in coke oven by-product workers

BACKGROUND: Urinary biological monitoring for benzene (by measuring benzene metabolites) in coke oven by-product workers produced the unexpected result that 2 out of 10 employees had significantly raised urinary S-phenylmercapturic acid (S-PMA). However, simultaneous personal air sampling showed no excessive airborne exposure. METHODS: Possible causes for this finding were investigated having excluded inhalation as the route of uptake. It was suspected that skin absorption via contaminated overalls was the possible mechanism and a standard frequency for overall change was introduced. RESULTS: Changing overalls after every four shifts reduced uptake levels to less than the equivalent of 1 ppm inhaled dose for all employees. CONCLUSION: Skin absorption of benzene in coke oven by-product workers from contaminated overalls can be significant and therefore overalls should be changed on a regular and frequent basis.     

SWORD '96: surveillance of work-related and occupational respiratory disease in the UK

Chest and occupational physicians who report to the SWORD surveillancescheme are estimated to have seen some 3,300 new cases of work-relatedrespiratory disease in 1996. This total has regained the levelrecorded prior to a low in 1995, probably because of improvedchest physician participation and the introduction of a samplingsystem for occupational physicians. Trends in disease incidencehave remained fairly constant with some changes only in pneumoconiosisand inhalation accidents. It is of concern that there has beenno evidence of a decrease in frequency of occupational asthmaor in any of the incriminated agents since the scheme beganin 1989. Comparison with other sources of data shows that, forasthma, SWORD records a relatively high frequency in women,a substantial proportion of whom do not appear to receive compensation.For mesothelioma, rates based on death certificates continuefor understandable reasons to run at about twice the level reportedto SWORD or as reflected by successful claims to the DSS forindustrial injuries benefit. The SWORD programme is now oneof six clinically-based reporting schemes which, by the endof 1997, are planned to cover all types of occupational diseasein the UK.     

Lead exposure in scaffolders during refurbishment construction activity--an observational study

The toxic effects of lead have been known for centuries. Occupational exposure to this chemical hazard has also been well documented in relation to various industry groups, including construction, where workers are recognized as being significantly exposed during refurbishment work, in particular through inhalation and ingestion of lead fumes and dust. It is easy to see how so-called 'burners', 'cutters' and 'blasters'--workers directly involved in removing old lead paint--may become exposed; the influence of personal hygiene, smoking, eating/drinking and nail biting has also been documented in the literature. We now report on one group, the scaffolders, not previously considered to be at risk. Although not directly involved in the paint removal, anecdotal and personal experience of the authors indicate that these workers, who erect and later dismantle access structures during the renovation of previously lead-painted surfaces, may take up significant amounts of lead, mainly by ingestion, to raise their personal blood lead levels (and body burden) in line with recognized 'lead workers'. Exposures of this magnitude would also bring the scaffolders involved in such refurbishment work under the Control of Lead at Work Regulations 1998. The authors make various recommendations on measures to minimize and control exposure of scaffolders to lead.     

Aesthesioneuroblastoma in a woodworker

A case is described of aesthesioneuroblastoma in a woodworker who had been exposed to wood dust for 25 years, without any individual or environmental protection. The case described supports the contention that occupational exposure to wood dust may have caused the neoplasm.     

Atrial fibrillation in a commercial diver

BACKGROUND: The torpedo ray is a fish with powerful electric organs, which can serve either as predatory tool or defensive weapon. The name comes from the Latin 'torpere', to be stiffened or paralysed, referring to the effect on someone who handles or steps on a living electric ray. AIM: To present an unusual case of atrial fibrillation due to electric shocks by the torpedo ray (electric ray). RESULTS: A 42-year-old male commercial diver presented with atrial fibrillation after receiving repeated electric shocks from a torpedo ray while on routine diving operations. Such occurrences are extremely rare and we could find no documented case in the medical literature. CONCLUSIONS: Electric current can damage the body by disrupting electric rhythms, inducing muscular spasms and burns. In this case, we report atrial fibrillation in a diver exposed to repeated electric shocks from a torpedo ray.     

Lung cancer mortality at a UK tin smelter

BACKGROUND: An earlier study of mortality among male former employees at a tin smelter in Humberside, UK, had identified excess mortality from lung cancer, which appeared to be associated with occupational exposure. AIMS: The aim of the present study was to investigate the relationship between lung cancer mortality and quantitative measures of exposure. METHODS: Using available records of occupational hygiene measurements, we established exposure matrices for arsenic, cadmium, lead, antimony and polonium-210 ((210)Po), covering the main process areas of the smelter. We established work histories from personnel record cards for the previously defined cohort of 1462 male employees. Three different methods of extrapolation were used to assess exposures prior to 1972, when no measurement results were available. Lung cancer mortality was examined in relation to cumulative inhalation exposure by Poisson regression analysis. RESULTS: No significant associations could be found between lung cancer mortality and simple cumulative exposure to any of the substances studied. When cumulative exposures were weighted according to time since exposure and attained age, significant associations were found between lung cancer mortality and exposures to arsenic, lead and antimony. CONCLUSIONS: The excess of lung cancer mortality in the cohort can most plausibly be explained if arsenic is the principal occupational carcinogen (for which the excess relative risk diminishes with time since exposure and attained age) and if there is a contribution to excess mortality from an enhanced prevalence of smoking within the cohort. The implications of the dose-response for arsenic exposure for risk estimation merit further consideration.