Occupational dental erosion from exposure to acids: a review

Objective Dental erosion is characterized as a disorder witha multifactorial aetiology including environmental acid exposure.The purpose of this article was to summarize and discuss theavailable information concerning occupational dental erosion. Methods Information from original scientific papers, case reportsand reviews with additional case reports listed in PubMed, Medlineor EMBASE [search term: (dental OR enamel OR dentin) AND (erosionOR tooth wear) AND (occupational OR worker)] were included inthe review. References from the identified publications weremanually searched to identify additional relevant articles. Results The systematic search resulted in 59 papers, of which42 were suitable for the present review. Seventeen papers demonstratedevidence that battery, galvanizing and associated workers exposedto sulphuric or hydrochloric acid were at higher risk of dentalerosion. For other industrial workers, wine tasters and competitiveswimmers, only a few clinical studies exist and these do notallow the drawing of definitive conclusions. Conclusion Occupational acid exposure might increase the riskof dental erosion. Evidence for occupational dental erosionis limited to battery and galvanizing workers, while data forother occupational groups need to be confirmed by further studies.     

Current best practice for the health surveillance of enzyme workers in the soap and detergent industry

This study defines current best practice for the health surveillance of workers who are potentially exposed to enzymes in the manufacture of enzymatic detergent products. It is recommended that health surveillance is performed 6-monthly for the first 2 years and annually thereafter. The health surveillance programme should include a respiratory questionnaire to detect symptoms, assessment of lung function to detect pre-symptomatic changes and an immunological test to detect specific immunoglobulin E (IgE) to enzymes. The International Union Against Tuberculosis and Lung Disease respiratory questionnaire should be used since it has been validated extensively for detecting asthma. Operators should observe the American Thoracic Society performance criteria for spirometers and standardized procedures for conducting spirometry. Since current airborne monitoring techniques for enzymes do not detect short-duration peak exposures, the incidence of employee sensitizations remains the most reliable measure of the integrity of environmental control. The Pepys skin prick test has been validated as a sensitive, specific and practical test for detecting specific IgE to many inhalant allergens including enzymes. For newly sensitized workers, a multi-cause investigation should be conducted to identify potential sources of exposure. Group results of immunological test results assist in the evaluation of workplace control measures, and should be used to monitor the effectiveness of hygiene and engineering programmes and to help prioritize areas for improvement. Positive responses to a questionnaire or abnormal spirometry should be assessed further. Occupational asthma should be excluded in any case of adult-onset asthma that starts or deteriorates during working life. This is particularly important because an accurate diagnosis of occupational asthma with early avoidance of exposure to its cause can result in remission of symptoms and restoration of lung function.     

The impact of educational interventions on primary health care workers' knowledge of occupational exposure to blood or body fluids

AIM: To assess the impact of educational interventions on primary health care workers' knowledge of management of occupational exposure to blood or body fluids. METHODS: Cluster-randomized trial of educational interventions in two National Health Service board areas in Scotland. Medical and dental practices were randomized to four groups; Group A, a control group of practices where staff received no intervention, Group B practices where staff received a flow chart regarding the management of blood and body fluid exposures, Group C received an e-mail alert containing the flow chart and Group D practices received an oral presentation of information in the flow chart. Staff knowledge was assessed on one occasion, following the educational intervention, using an anonymous postal questionnaire. RESULTS: Two hundred and fifteen medical and dental practices were approached and 114 practices participated (response rate 53%). A total of 1120 individual questionnaires were returned. Face to face training was the most effective intervention with four of five outcome measures showing better than expected knowledge. Seventy-seven percent of staff identified themselves as at risk of exposure to blood and body fluids. Twenty-one percent of staff believed they were not at risk of exposure to blood-borne viruses although potentially exposed and 16% of exposed staff had not been immunized against hepatitis B. Of the 856 'at risk' staff, 48% had not received training regarding blood-borne viruses. CONCLUSIONS: We found greater knowledge regarding management of exposures to blood and body fluids following face to face training than other educational interventions. There is a need for education of at risk primary health care workers.     

Biomonitoring of titanium, mercury, platinum, rhodium and palladium in dental health care workers

BACKGROUND: In dentistry, titanium, mercury, platinum, rhodium and palladium are used to produce dental fillings. Therefore, dental workers who apply such materials may be exposed to these metals. METHODS: The study concerned 40 healthy subjects-20 controls and 20 dental health care workers-to determine serum and urinary levels of the aforementioned metals by inductively coupled plasma mass spectrometry. RESULTS: Mean urinary and serum titanium did not reveal statistically significant differences in the two groups. The very low urinary and serum levels of mercury, platinum, rhodium and palladium prevented us from making a statistical evaluation between the two groups. CONCLUSIONS: We did not find a significant increase in serum and urinary titanium levels in dental health care workers. Measurement of mercury, platinum, rhodium and palladium in urine and serum was not useful in determining occupational exposure.     

Dental surgeons with natural rubber latex allergy: a report of 20 cases.

Latex allergy is becoming a major occupational health issue and dental surgeons are at risk from becoming sensitized to natural rubber latex. A study was conducted to investigate risk factors and glove-related symptoms reported by dentists with natural rubber latex allergy. Twenty dentists, who had undergone serological or dermatological testing for a Type I allergy to latex, were identified from a questionnaire survey. Risk factors investigated were: gender, years in clinical practice, exposure to latex gloves, atopic history and food allergy. The majority of dentists (75%) gave an atopic history. Glove-related adverse reactions ranged from cutaneous to systemic manifestations. All twenty dentists reported itching of the hands in response to latex gloves. One respondent was unable to continue in dental practice because of her glove-related allergies; nineteen dentists were able to continue by using synthetic, non-latex gloves.     

Oral conditions among workers in the Danish granite industry

The purpose of the study was to evaluate the oral health situation of workers in the Danish granite industry, in particular, to describe the prevalence and severity of dental abrasion. Measurements of the work environment showed that the workers were exposed to abrasive quartz dust. A total of 39 workers (72%) completed a questionnaire on their dental health, work environment, and symptoms from the masticatory system. Only 10% had been treated by school dental services, and only 51% made regular visits to the dentist. Consequently, the clinical examinations revealed a high prevalence of dental caries (mean number of decayed, missing, and filled surfaces 87.2). The workers' periodontal conditions were poor; the mean percentage of teeth with gingivitis, calculus and pockets deeper than 5 mm was 13.4. The prevalence of dental abrasion was 100%; in particular, abrasion was observed on the front teeth. The severity of abrasion and the affection ratio increased by duration of exposure to dust. In conclusion, dental abrasion induced by work-related dust should be considered an occupational disease.     

Olfactory sensitivity in medical laboratory workers occupationally exposed to organic solvent mixtures

BACKGROUND: Published epidemiological information relating the effects of occupational exposure to organic solvents (OS) to olfaction is limited. AIMS: The objectives of this pilot study were to measure the chemosensory abilities of medical laboratory employees occupationally exposed to OS mixtures, to compare these with control workers employed within the same occupational setting and to correlate chemosensory performance with OS exposure history and with employees' hedonic (pleasantness) perceptions about workplace OS odors. METHODS: Twenty-four medical laboratory employees (OS-exposed technicians plus control workers minimally exposed to OS) completed a health-related questionnaire, a test of pyridine odor detection threshold, along with a gustatory detection threshold test involving aqueous quinine solutions. Estimates of cumulative hours of OS exposure (CSI) were calculated from self-reports. RESULTS: OS-exposed laboratory technicians detected weaker concentrations of pyridine odor. Positive correlations were detected between CSI estimates to both pyridine detection and the degree that participants reported that OS odors were present in the workplace. However, no association was detected between pyridine detection and how unpleasant workplace OS odors were perceived. The OS-exposed participants were able to detect weaker concentrations of quinine. Compared to controls, OS-exposed workers complained more of experiencing several symptoms while working, including headaches, nasal irritation and mild cognitive impairment. CONCLUSIONS: The results of this cross-sectional pilot study indicated that, compared to controls, medical laboratory technicians exposed to low-level OS mixtures displayed evidence of elevated olfactory sensitivity (hyperosmia) to pyridine odor. The relation of this study's results to chemical intolerance warrants further investigation.     

Smoking and Exposure to Occupational Hazards in 8,304 Workers in Guangzhou, China

This cross-sectional study aimed to describe the pattern ofsmoking in relation to occupational hazard exposure in a workingpopulation in Guangzhou, China. In 1994, data on smoking andoccupational hazard exposure from occupational health recordsof 8,304 subjects aged 35 years or older from 47 randomly selectedfactories were studied. About 49% of the men and 55% of thewomen were exposed to dust, chemicals or other hazards. Theprevalence of smoking was 56.1% in men and in women. The prevalenceof smoking in men was higher in those who were younger, withprimary education or who were workers. In women, those who wereolder, with primary education or in management jobs had highersmoking prevalence. In men and women, subjects who were exposedto occupational hazards had higher smoking prevalence: the highest(71.6%) was found in male workers exposed to dust. Urgent tobaccocontrol measures are needed to prevent the epidemic of smoking-relatedand occupation-related diseases in the workplace in China.     

Dehydroabietic acid as a biomarker for exposure to colophony

BACKGROUND: Colophony (rosin) is a natural product derived from the resin of coniferous trees with many industrial applications including soldering fluxes. Exposure to colophony fume through soldering is one of the leading causes of occupational asthma in the UK. AIMS: To assess occupational exposure to colophony from solder fume at selected workplaces in the UK and to investigate the use of dehydroabietic acid (DHA) as a biomarker of exposure. METHODS: Six companies in the UK electronics industry were visited and occupational hygiene assessments of extent and control of exposure to rosin-based solder flux fume were undertaken. Urine samples were analysed for one of the main constituents of rosin, DHA. RESULTS: There was a positive linear relationship between airborne exposure to solder fume and urinary DHA level. The levels of urinary DHA measured in UK workers were significantly lower than those previously measured in African workers because of the use of appropriate exposure control measures, for example, local exhaust ventilation with fixed ducting and flexible hose, tip extraction, etc. It is suggested that good occupational hygiene practice would result in urinary DHA levels of <3 micromol/mol creatinine in a post-shift urine sample. CONCLUSIONS: Urinary DHA is a valid biomarker of exposure to colophony in solder fume. Further work on the excretion kinetics of urinary DHA, the possibility of skin absorption and further occupational hygiene surveys would be beneficial.     

Mercury derived from dental amalgams and neuropsychologic function

There is widespread concern regarding the safety of silver-mercury amalgam dental restorations, yet little evidence to support their harm or safety. We examined whether mercury dental amalgams are adversely associated with cognitive functioning in a cross-sectional sample of healthy working adults. We studied 550 adults, 30-49 years of age, who were not occupationally exposed to mercury. Participants were representative of employees at a major urban medical center. Each participant underwent a neuropsychologic test battery, a structured questionnaire, a modified dental examination, and collection of blood and urine samples. Mercury exposure was assessed using a) urinary mercury concentration (UHg); b) the total number of amalgam surfaces; and c) the number of occlusal amalgam surfaces. Linear regression analysis was used to estimate associations between each marker of mercury exposure and each neuropsychologic test, adjusting for potential confounding variables. Exposure levels were relatively low. The mean UHg was 1.7 micro g/g creatinine (range, 0.09-17.8); the mean total number of amalgam surfaces was 10.6 (range, 0-46) and the mean number of occlusal amalgam surfaces was 6.1 (range, 0-19). No measure of exposure was significantly associated with the scores on any neuropsychologic test in analyses that adjusted for the sampling design and other covariates. In a sample of healthy working adults, mercury exposure derived from dental amalgam restorations was not associated with any detectable deficits in cognitive or fine motor functioning.     

Severe headache associated with occupational exposure to Stoddard solvent

We report a case of recurrent headaches in a woman with a workplace exposure to airborne (misted) lubricating fluid containing Stoddard solvent. For 2 months, the employee was seen by her family physician, a neurologist and an ophthalmologist. All attempted to diagnose the cause of and treat her headaches. Despite extensive testing, no etiology was discovered. Her headaches continued despite the use of medications. The employee, suspecting an occupational connection, changed the lubricating fluid at her workstation to a non-Stoddard solvent. Within 2 days she reported the complete resolution of her headaches with no further recurrences. A thorough occupational history and literature review supported exposure to Stoddard solvent as the probable source of her headaches.     

Analysis of the clinical state of patients with occupational asthma following cessation of exposure to allergens

The purpose of this study was to evaluate the health state of patients with occupational asthma after cessation of occupational exposure to bakery allergens. A follow-up study of 56 subjects with occupational asthma was carried out. Subjects were examined twice: 1-6 months after removal from occupational exposure and 36 or 48 months later. Clinical state analysis both at diagnosis and re-examination was performed with the use of a questionnaire. Functional spirometric tests and skin prick tests and/or specific serum IgE were carried out during both examinations at points of time at which the subjects regarded their asthma symptoms as least severe. According to the subjective evaluation of the patients' clinical state, some improvement could be noticed 36 or 48 months after removal from work. Forced expiratory volume in one second (FEV1) and peak respiratory flow (PEF) did not change significantly. Total serum IgE concentration decreased in only two subjects, but the mean value of total IgE level did not significantly differ at the first and second examination after the cessation of occupational exposure. There was no significant difference in the number of positive skin prick tests to common and occupational allergens between the first and second examination. The majority of patients with occupational asthma reporting subjectively on their symptoms indicated an improvement in their clinical state 2-3 years after removal from occupational exposure. The intensity of skin prick tests was not reduced in the studied group. Non-specific bronchial hyper-responsiveness was not reduced in the majority of subjects with occupational asthma at least 2 years after cessation of occupational exposure.     

Cardiovascular effects of occupational exposure to carbon disulphide

The objective of this study was to investigate the effect of occupational exposure to carbon disulphide (CS2) on the total cholesterol, blood pressure and prevalence of coronary heart disease (CHD). A cross-sectional study involving 252 viscose rayon workers and 252 age and sex matched controls was carried out. Depending on the job and specific work place, the CS2 concentrations were between 10 and 64 mg/m3. A cumulative exposure index (CS2 index) was calculated for each worker by multiplying the number of years he had held a particular job with the CS2 concentrations in that job. CHD prevalence among the exposed was higher than among the controls; the difference reaching significance only for highly exposed workers. Cholesterol levels were significantly higher in both highly and moderately exposed groups. In conclusion, the results demonstrated that occupational exposure to CS2 increases total cholesterol and the risk for CHD. While the risk for CHD is increased in workers exposed to high CS2 concentration for many years (CS2 index > or = 300), even the relatively modest exposure (CS2 < 300) may increase the serum cholesterol.     

Subjective assessments of safety, exposure to chemicals and use of personal protection equipment in seafaring

BACKGROUND: Most of the scientific publications from the maritime area are studies about the mortality and morbidity, while studies about the present hazards of potentially dangerous exposures are relatively rare. AIMS: To describe the seafarers' assessments of the occupational safety on board, their exposure to chemicals and the use of personal protection equipment and to identify the areas for further risk assessment and preventive measures. METHODS: A questionnaire study was carried out in 11 countries among seafarers who attended a regular health examination. RESULTS: The total number of seafarers who participated in the study was 6461 (response rate 93.7%). The occupational safety on board was assessed to be very good or good in 82%. Multivariate analyses showed that the safety was assessed as lowest among ratings, seafarers<30 years of age, work in the engine rooms and on dry cargo ships. It was highest on crude oil tankers and supply ships. Fifty-five per cent of seafarers were exposed to chemicals. Personal protection equipment to chemicals was used 'always/almost always' in 93% of the exposed. Multivariate analysis showed that the use of personal protection was highest on deck, on the largest ships, on roll-on roll-off ships and on crude oil tankers. CONCLUSION: The occupational safety and the use of personal protective equipment was assessed to be significantly different in some strata of the population and in specific working areas and types and sizes of ships.     

Prevalence of dental erosion caused by sulfuric acid fumes in a smelter in Japan]

The effect of occupational sulfuric acid exposure and other factors on teeth was explored in a cross-sectional study with blind dental examinations. Among 350 male workers in a copper-smelter in Japan, 28 had mild dental erosion with silky-glazed opaque appearance of the enamel and/or shallow concavities on the enamel. While opaqueness was observed in 20 and concavities found in 11 workers, only 3 had both signs, suggesting that the concave lesions were often accompanied with enough remineralization to keep the dental surface gloss, possibly due to acid exposure at a low level. The cases had a history of working in an electrolytic refining plant (36%), significantly more than in the non-cases (14%, p < 0.05). Some significant differences were found between the cases and the non-cases: the cases were older, had less dental plaque, less gingivitis, and more frequent toothbrushing habits. No significant differences were observed in possibly related dietary habits such as several types of acidic drinks. It was concluded that the present cases with dental erosion were most probably associated with occupational acid exposure. The risk ratio of cross-sectional prevalence of dental erosion for those with a history of electrolytic refining plant work was 3.0 (95% CI: 1.3-6.7) compared with those without a history of acid exposure. Whether the present work environment can still develop new cases of dental erosion remains to be studied.     

Health and employment after a diagnosis of occupational asthma: a descriptive study

The objectives of this study were to describe changes in asthmaand employment after diagnoses of occupational asthma reportedto the SWORD project. Questionnaires were sent to 312 physiciansfor all 1,940 cases of occupational asthma reported from 1989–92;1,769 (91%) were returned but information was available foronly 1,317 (68%). Of patients reported by occupational physicians,45% had recovered from asthma compared to only 14% of thosereported by chest physicians (excluding medicolegal cases),presumably because of differences in severity. Proportions withthe same employer were 49% and 48% respectively. Patients exposedfor a year or more after diagnosis recovered from asthma lessfrequently but were more often employed than those exposed forless than a year. Among those whose asthma was attributed tohigh molecular weight agents, smokers had developed asthma earlierafter exposure began than others but had the best prognosis.Asthma developed following a single high exposure in 18 cases(2%), of which 13 were to irritants and five to known sensitizers.     

Occupational toxicology and the control of exposure to pharmaceutical agents at work

BACKGROUND: The pharmaceutical industry employs >350 000 people worldwide in operations including research and development (R&D), manufacturing, sales and marketing. Workers employed in R&D and manufacturing sectors are potentially exposed to drug substances in the workplace that are designed to modify physiology and also to chemical precursors that are potentially hazardous to health. Pharmaceutical workers are at risk from adverse health effects, including occupational asthma, pharmacological effects, adverse reproductive outcomes and dermatitis. AIM: This study aimed to describe the approaches taken by pharmaceutical companies for identifying and communicating potential adverse health effects that may result from workplace exposures and in setting 'in-house' exposure control limits and to highlight the challenges in controlling workplace exposures to increasingly potent compounds. METHOD: The literature was reviewed by searching the Medline and HSELine databases. RESULTS: The findings are presented in five sections, covering: test methods and approaches to occupational toxicology; hazard communication; approaches to setting health-based occupational exposure limits for pharmaceutically active agents; recent approaches to risk control; and occupational hygiene and exposure controls. CONCLUSION: Significant efforts have been directed at predicting and evaluating potential occupational health hazards in the pharmaceutical industry. The pharmaceutical industry has provided leadership in controlling exposure to hazardous substances. Much of this work has been driven by a real need to control occupational exposures to substances that can have profound adverse health effects in exposed employees and that are becoming increasingly more potent.     

Occupational exposure and health problems in small-scale industry workers in Dar es Salaam, Tanzania: a situation analysis

BACKGROUND: Workers in informal small-scale industries (SSI) in developing countries involved in welding, spray painting, woodwork and metalwork are exposed to various hazards with consequent risk to health. Aim To assess occupational exposure and health problems in SSI in Dar es Salaam, Tanzania. METHODS: Focused group discussions (FGD) were conducted among SSI workers. Participants were assessed for exposure to occupational and environmental hazards, the use of protective equipment and health complaints by interview. The findings were discussed with participants and potential interventions identified. RESULTS: Three hundred and ten workers were interviewed (response rate 98%). There was a high level (>90%) of self-reported exposure to either dust, fumes, noise or sunlight in certain occupational groups. There was low reported use of personal protective equipment. There was a high level of self-reported occupational health problems, particularly amongst welders and metalworkers. Workers reported their needs as permanent workplaces, information on work related hazards, water and sanitation, and legislation for SSI. CONCLUSIONS: In SSI in Tanzania, our study suggests that workers have high levels of exposure to multiple health hazards and that use of protective equipment is poor. This group of workers warrants improved occupational health and safety provision.     

Air blast circuit breaker noise and hearing loss: a multifactorial model for risk assessment

The assessment of the risk to hearing from impulse noise exposure may be a problem for the occupational physician because existing legislative and international noise exposure standards deal primarily with continuous noise, and are not valid in excess of the peak exposure limit of 200 pa (140 dB). Noise exposure in excess of this level, for example that due to firearms, is frequently perceived as harmful, but this is not necessarily the case, as impulse noise standards do, in fact, allow exposure with a maximum in the order of 6.3 kPa (170 dB). To illustrate this, a cross-sectional group of electrical transmission workers have been studied who were exposed to significant levels of impulse noise from air blast circuit breakers and firearms. Important hearing loss factors have been identified by means of a specially designed questionnaire. Using the Health & Safety Executive definition, the risk of hearing loss was determined by calculating prevalence odds ratios (ORs) for exposure to these factors. The OR for those with fewer than eight unprotected air blast circuit breaker exposures was 2.27 (95% confidence interval (CI), 1.01-5.08), whilst for those with more than eight exposures the OR was 2.10 (95% CI, 0.97-4.54). For firearm exposure, ORs of 1.61 (95% CI, 0.95-2.74) were noted in the medium exposure group and 2.05 (95% CI, 1.08-3.86) in the high exposure group. When all the factors were included in the model, the most significant factor was age. The study gives support to the impulse noise exposure criteria, confirming the borderline risk from air blast circuit breaker noise exposure and the relative safety of moderate gunfire exposure.     

Renal cell carcinoma and occupational exposure to chemicals in Canada

This study assesses the effect of occupational exposure to specific chemicals on the risk of renal cell carcinoma in Canada. Mailed questionnaires were used to obtain data on 1279 (691 male and 588 female) newly diagnosed, histologically confirmed renal cell carcinoma cases and 5370 population controls in eight Canadian provinces, between 1994 and 1997. Data were collected on socio-economic status, smoking habit, alcohol use, diet, residential and occupational histories, and years of exposure to any of 17 chemicals. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived using unconditional logistic regression. The study found an increased risk of renal cell carcinoma in males only, which was associated with occupational exposure to benzene; benzidine; coal tar, soot, pitch, creosote or asphalt; herbicides; mineral, cutting or lubricating oil; mustard gas; pesticides; and vinyl chloride. Compared with no exposure to the specific chemical, the adjusted ORs were 1.8 (95% CI = 1.2-2.6), 2.1 (1.3-3.6), 1.4 (1.1-1.8), 1.6 (1.3-2.0), 1.3 (1.1-1.7), 4.6 (1.7-12.5), 1.8 (1.4-2.3) and 2.0 (1.2-3.3), respectively; an elevated risk was also associated with exposure to cadmium salts and isopropyl oil. The risk of renal cell carcinoma increased with duration of exposure to benzene, benzidine, cadmium, herbicides and vinyl chloride. Very few females were exposed to specific chemicals in this study; further research is needed to clarify the association between occupational exposure to chemicals and renal cell carcinoma in females.