Concerns for asthma at pre-placement assessment and health surveillance in platinum refining--a personal approach

Platinum, a noble metal, is inert in the body and has an important use in medical applications. It is used in autocatalysts to control harmful vehicular emissions and the catalytic effects improve efficiencies of pharmaceutical and petrochemical processes. The refining process involves exposure to halogeno complex salts of platinum which are potent allergens. They induce symptoms typical of a type I allergy, the most significant of which is asthma. Platinum refining not only exposes employees to the risk of sensitization to these salts but also to respiratory irritants. Inhalation of these aggravates pre-existing asthma. The increasing incidence of asthma in the community requires that prospective employees for platinum refining be assessed carefully to establish their respiratory health status in relation to the risk of sensitization or aggravation of pre-existing asthma. Routine medical surveillance has been shown to reduce persistence of asthma in sensitized workers who cease exposure to the platinum salts upon diagnosis. Skin prick test using dilute platinum salt solutions can detect sensitization at an early stage and this has become the mainstay of surveillance programmes as it is objective and reproducible as well as predictive for the development of symptoms when exposure is allowed to continue. Symptoms are not sensitive or specific. Smoking is a significant risk factor.     

20 years of medical surveillance on exposure to allergenic and non- allergenic platinum compounds: the importance of chemical speciation

OBJECTIVES: Chloroplatinates are potent allergens but other soluble platinum compounds such as tetraammine platinum dichloride (TPC) do not provoke reactions in subjects who are sensitive to chloroplatinates. TPC has been used in the manufacture of autocatalysts for 20 years. This study analyses 20 year data on exposure to soluble platinum compounds and medical surveillance to confirm that TPC is not allergenic. METHODS: Workers in three distinct operations were exposed to soluble platinum compounds as chloroplatinates, chloroplatinates with TPC, or to TPC alone. Results of personal air sampling for soluble platinum compounds were compared together with the results of medical surveillance. RESULTS: The levels of exposure to soluble platinum compounds in each operation were comparable but the incidence of allergy was significantly different. In a subgroup of workers consistently exposed to chemical processes in each operation, the cumulative chance of being sensitised after 5 years of exposure was estimated as 51% for chloroplatinate exposure, 33% for mixed exposure, and 0% for TPC alone. The differences in sensitisation rates could not be explained by age, sex, and atopy. Nor could they be explained by the increased frequency of smoking in the workers with chloroplatinate exposure, despite the markedly higher risk of sensitisation in smokers. The differences could only be explained by the chemical stability of TPC. CONCLUSIONS: This study shows that the soluble platinum compound TPC is not allergenic under normal industrial conditions. Characterisation of the chemical compound (speciation) is essential to prevent stringent exposure limits being imposed for all soluble compounds on a generic basis.

 

     

Solar ultraviolet radiation and skin cancer

Background Incidence rates of skin cancer, both non-melanomaskin cancer and (malignant/cutaneous) melanoma, are rising inGreat Britain. It is widely accepted that solar ultravioletradiation (UVR) is the main causal factor for these neoplasms.Many people are occupationally exposed to solar UVR, includingfarmers, construction workers and some public service workers. Aim The aim of this article is to review the key epidemiologicpapers on occupational solar exposure and skin cancer and discussthe relationships found. Method A literature search was conducted using online databasesand article bibliographies. A full review of all available studieswas not carried out, as only key studies on occupational exposurewere required. Results There is a clear association between solar radiationand skin cancer. The mechanisms for induction vary between thetypes of skin cancer and these cannot be solely attributed tooccupational exposures. Conclusions There is great difficulty in separating the effectsof occupational and recreational solar UVR exposure; therefore,any results discussed in this review should be interpreted withcaution. However, it is clear that solar UVR exposure does induceskin cancer and protective measures should be taken in an attemptto reduce the burden of occupational skin cancer in Great Britain.     

Health care workers' exposure to blood-borne pathogens in Lebanon

Background Accidental exposure to blood-borne pathogens (BBPs)is a risk for health care workers (HCWs). Aim To study the pattern of occupational exposure to blood andbody fluids (BBFs) at a tertiary care hospital. Methods This study reports a 17-year experience (1985–2001)of ongoing surveillance of HCW exposure to BBFs at a 420-bedacademic tertiary care hospital. Results A total of 1590 BBF exposure-related accidents werereported to the Infection Control Office. The trend showed adecrease in these exposures over the years with an average ±standard error of 96 ± 8.6 incidents per year. In thelast 6 years, the average rate of BBF exposures was 0.57 per100 admissions per year (average of needlestick injuries alonewas 0.46 per 100 admissions). For 2001, the rates of exposurewere found to be 13% for house officers, 9% for medical student,8% for attending physicians, 5% for nurses, 4% for housekeeping,4% for technicians and 2% for auxiliary services employees.The reason for the incident, when stated, was attributed toa procedural intervention (29%), improper disposal of sharps(18%), to recapping (11%) and to other causes (5%). Conclusions The current study in Lebanon showed that exposureof HCWs to BBPs remains a problem. This can be projected toother hospitals in the country and raises the need to implementinfection control standards more efficiently. Similar studiesshould be done prospectively on a yearly basis to study ratesand identify high-risk groups.     

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.     

Occupational paraffin-induced pulmonary fibrosis: a 25-year follow-up

Abstract Exogenous lipid pneumonia can exceptionally be causedby occupational exposure to paraffin. The authors report a caseof severe interstitial pulmonary disease induced by occupationalexposure to paraffin, leading to delayed fibrosis over a 25-yearfollow-up, despite cessation of exposure.     

Salivary acetylcholinesterase as a biomarker for organophosphate exposure

Background Workers exposed to organophosphate (OP) pesticidesare required to undergo periodic statutory medical surveillancein several countries. Aim To study the relationship between serum, erythrocyte andsaliva acetylcholinesterase (AChE) levels and to explore theuse of salivary AChE as potential biomarker for OP exposure. Methods A cross-sectional study was conducted on 19 healthyadult male lead-exposed workers who were undergoing six monthlystatutory medical examination. Passive drool saliva sampleswere collected from each worker. Each blood sample was testedfor serum and erythrocyte AChE, and each saliva sample was testedfor AChE. Results Among the 19 subjects, the mean (±standard deviation)of salivary, erythrocyte and serum AChE/cholinesterase were22.7 (±17.4), 17171 (±1467), 8861 (±1876)U/l, respectively. There was a moderate correlation betweensalivary and erythrocyte AChE (r = 0.42, P = 0.071), but notsalivary and serum AChE (r = –0.17, P = 0.48). The levelof AChE in saliva was 1820 times lower than AChE in erythrocytes. Conclusion It is probably not feasible to use saliva as a replacementfor blood for the measurement of AChE levels. This is becauseof the much lower levels of AChE in saliva relative to erythrocytes,the weak correlation between the two measurements and the previouslyreported high intra-individual variation of salivary AChE.     

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.     

Exposures to blood and body fluids in Brazilian primary health care

Background Primary health care workers (HCWs) represent a growingoccupational group worldwide. They are at risk of infectionwith blood-borne pathogens because of occupational exposuresto blood and body fluids (BBF). Aim To investigate BBF exposure and its associated factors amongprimary HCWs. Methods Cross-sectional study among workers from municipal primaryhealth care centres in Florianópolis, Southern Brazil.Workers who belonged to occupational categories that involvedBBF exposures during the preceding 12 months were interviewedand included in the data analysis. Results A total of 1077 workers participated. The mean incidencerate of occupational BBF exposures was 11.9 per 100 full-timeequivalent worker-years (95% confidence interval: 8.4–15.3).The cumulative prevalence was 7% during the 12 months precedingthe interview. University-level education, employment as a nurseassistant, dental assistant or dentist, higher workload score,inadequate working conditions, having sustained a previous occupationalaccident and current smoking were associated with BBF exposures(P 0.05). Conclusions Primary Health Care Centres are working environmentsin which workers are at risk of BBF exposures. Exposure surveillancesystems should be created to monitor their occurrence and toguide the implementation of preventive strategies.     

Which agents cause reactive airways dysfunction syndrome (RADS)? A systematic review

Aim To identify those agents reported as being associated withreactive airways dysfunction syndrome (RADS). Methods A systematic review was undertaken. Abstracts were screenedand those selected reviewed against pre-determined diagnosticcriteria for RADS. Results Significant information gaps were identified for allmeasures of interest. In some articles, even the causative agentwas not reported. The most commonly reported agents were chlorine(nine subjects), toluene di-isocyanate (TDI) (n = 6) and oxidesof nitrogen (n = 5). Most exposures occurred in the workplace(n = 51) and affected men (60%). Dyspnoea (71%) and cough (65%)were the commonest symptoms. Median symptom duration was 13months (interquartile range = 6.5–43.5) for RADS. Conclusions Although the most commonly reported agent associatedwith RADS was chlorine, the main finding of a general lack ofadequate information on exposure, investigation and outcomesuggests that to better explore RADS a more structured approachto gathering information is required. A minimum data set forreporting RADS cases is proposed.     

Acute respiratory symptoms among sisal workers in Tanzania

Background Few studies have focused on respiratory health effectsamong sisal workers. Aim To report on the prevalence of acute respiratory symptomsamong sisal processors. Methods We interviewed 163 dust-exposed brushing and decorticationworkers and 31 low-exposed security workers from six sisal estatesin Tanzania using a modified symptom score questionnaire todetermine the prevalence of acute respiratory symptoms duringwork. Groups were compared using chi-square tests, Fisher'sexact tests, t-tests and logistic regression, adjusting forconfounding factors. Results After the first working day of the week, 73% of thebrushing workers reported dry cough, 66% sneezing, 65% productivecough, 63% running nose and 34% stuffy nose. Brushing workershad a significantly higher prevalence of these symptoms thandecortication workers. Brushing and decortication workers hadsignificantly more dry cough and sneezing than the control groupof security workers, when adjusting for age, smoking, past respiratorydiseases and residence. Conclusion Processors of sisal fibre have a high prevalenceof acute respiratory symptoms. More detailed studies on workand health in sisal estates are needed, including exposure studies.     

Medical surveillance and long-term prognosis of occupational allergy due to platinum salts

Purpose

Medical surveillance of workers in precious metals refineries and catalyst production plants is well established in many countries as a measure to prevent occupational asthma due to platinum (Pt) salts. It was the aim of this study to evaluate the impact of medical surveillance and to define prognostic factors with an emphasis on exposure determinants.

Methods

As part of an observational longitudinal study, 96 workers from German precious metals refineries and catalyst production plants with Pt salt allergy underwent a second examination several years (median 67 months) after the initial diagnosis was made.

Results

When the second examination was conducted, 92 subjects (96 %) had already been transferred to jobs with very low or no exposure to Pt salts. The number of subjects with sensitization to Pt salt as assessed by skin prick test (SPT_Pt) decreased from 86 to 52 %, and there was a clear improvement for rhinitis, conjunctivitis and contact urticaria between both examinations. Although the number of subjects with asthma symptoms decreased significantly, at the second examination 74 subjects (77 %) continued to suffer from asthma and 51 subjects (53 %) received asthma medication. Airway obstruction or bronchial hyperresponsiveness persisted in 83 subjects (86 %).

Conclusions

Secondary prevention in subjects with occupational exposure to Pt salts, as practiced for over 25 years in Germany could not avoid persistent asthma in the majority of cases, although improvements occurred. This study reveals the limitations of the concept that removal from exposure after the occurrence of respiratory symptoms may prevent chronic asthma. It is recommended that removal from exposure should be done immediately after the occurrence of a positive SPT_Pt, irrespective of symptoms.

     

Occupational eye injuries: a continuing problem

Background Ocular trauma is a worldwide cause of visual morbidity,a significant proportion of which occurs in the workplace. Thisis largely preventable with the use of protective eyewear andstrict compliance. Aim To analyse the type of occupational eye injuries that occurand to document the use of eye protection in patients presentingto a UK district general hospital. Methods A pilot retrospective case note analysis of all ocularinjuries seen in one calendar month was performed. A prospectivesurvey of consecutive occupational ocular injuries presentingto this district general accident and emergency (A&E) departmentover a 2-month period was then carried out. Demographics, aetiology,eye protection usage and clinical details were recorded andanalysed. Results Of all eye patients attending this A&E, 31% (87/283)were due to occupational eye injuries. Of 55 prospectively reviewedpatients with occupational eye injuries, the majority had minorinjuries. Of the cases where eye protection was recorded, 56%(18/32) were not wearing any protection and 44% (14/32) woreeye protection at the time of injury. Conclusions Occupational eye injuries are a commonly seen ocularcomplaint in the A&E department. Provision of appropriateeyewear protection and worker education is required to minimizethe incidence of ocular injury in the workplace.     

Fatigue and health in a seafaring population

Background Occupational fatigue is relatively common withinthe general population and has been linked to reduced performance,injury and longer term ill-health. Despite growing acknowledgementof this problem in the maritime sector, little research hasbeen conducted into the risk factors, prevalence and consequencesof seafarers' fatigue. Aims To examine the prevalence of fatigue among seafarers, identifypotential risk factors and assess possible links with poor performanceand ill-health. Methods Cross-sectional questionnaire survey of seafarers workingin the offshore oil support, short-sea and deep-sea shippingindustries. A number of tools were used including the fatiguesubscale of the profile of fatigue-related symptoms, the CognitiveFailures Questionnaire, the General Health Questionnaire andthe SF36 General Health scale. Results In all, 1855 questionnaires were completed giving anoverall response rate of 20%. Fatigue symptoms were associatedwith a range of occupational and environmental factors, manyunique to seafaring. Reporting a greater number of risk factorswas associated with greater fatigue [e.g. OR = 2.53 (1.90–3.35)for those with three or four risk factors and OR = 9.54 (6.95–13.09)for those with five or more risk factors]. There was also astrong link between fatigue and poorer cognitive and healthoutcomes, with fatigue the most important of a number of riskfactors, accounting for 10–14% of the variance. Conclusions Seafarers' fatigue could impact on safety withinthe industry and may be linked to longer term individual ill-health.It can only be addressed by considering how multiple factorscombine to contribute to fatigue.     

Platinum salt sensitivity in refinery workers: incidence and effects of smoking and exposure.

OBJECTIVE--To measure the incidence of platinum salt sensitivity (PSS) in refinery workers and examine the influence of cigarette smoking and exposure to platinum salts on sensitisation. DESIGN--A prospective cohort study with examination of workers at quarterly intervals for 18 months, and again at 24 months. SETTING--A South African primary platinum refinery. SUBJECTS--78 new recruits, selected by the refinery's usual procedure, without apparent atopy and in good respiratory health. RESULTS--After 24 months 32 (41%) subjects had been diagnosed PSS and were subsequently medically separated. Twenty two (28%) cases were confirmed by positive skin prick test to platinum salts, 10 (13%) cases were symptomatic but skin prick negative. Incidence of cases per 100 person-months was 1.9 skin prick positive and 0.8 negative. Risk of sensitisation was about eight times greater for smokers than non-smokers, and six times greater for high exposure than low exposure. CONCLUSION--Smoking and intensity of exposure were definitely associated with development of PSS. Positive responses to platinum salt skin prick test had a 100% positive predictive value for symptoms and signs of PSS if exposure continued.     

Relationship between job, lifestyle, age and occupational injuries

Background Physical job demands (PJD), age, disability and lifestylemay influence the risk of occupational injury. Aim To assess the relationships between PJD, lifestyle and injuryin workers of various ages. Methods A total of 2888 randomly selected workers from northeasternFrance, aged 15, completed a postal questionnaire. The PJD scorewas defined as the total number of the following reported jobdemands: using pneumatic tools, other vibrating hand tools,hammers, machine tools or vibrating platforms and exposure tomanual handling tasks, awkward postures, high pace of work,high physical workload, work at heights, work in adverse climatesor exposure to noise, cold or heat. Data were analysed usinglogistic regression. Results Nine per cent of subjects reported an injury duringthe previous 2 years. The PJD score was related to the injuryrate for workers aged 45: crude odds ratio (OR) 3.5 (95% confidenceinterval = 1.5–8.0) for PJD = 1, 5.0 (2.2–11.3)for PJD = 2–3 and 14.5 (6.5–32.2) for PJD 4, versusPJD = 0. Lower ORs were found for those aged <30 (1.4, 4.2and 9.9, respectively) and 30–44 (1.5, 4.4 and 6.5, respectively).The differences between age groups remained when controllingfor all factors studied. Obesity, smoking and musculoskeletaldisorders were associated with injury risk in workers aged 45(adjusted ORs 1.7–2.6). Smoking was also an injury riskfactor for workers aged <30. Conclusions PJD and lifestyle have a higher impact on injuryrates among older workers than among younger ones. Injury preventionshould address reducing PJD and improving relevant lifestylefactors, especially for older workers.     

The sensitivity and specificity of thermometry and plethysmography in the assessment of hand-arm vibration syndrome

Background Finger plethysmography and thermometry are objectivemeasures used to assess the vascular aspect of hand–armvibration syndrome (HAVS). Research to date shows poor correlationbetween these tests and Stockholm Workshop Scale (SWS) vascularstage. Clinicians, researchers and compensation boards requireobjective means to diagnose and quantify HAVS. Aims To define the specificity and sensitivity of thermometryand plethysmography using the SWS as the reference criterion.A secondary goal was to consider cut points for the tests optimizingsensitivity and specificity. Methods A cross-sectional analysis was conducted on HAVS patientsseen at an occupational medicine specialty clinic. Plethysmographyand thermometry were analyzed using SWS vascular stage as theoutcome variable. Logistic regression controlled for age, smokingand time since last vibration exposure and use of vasoactivemedications. The sensitivity and specificity of the combinedtests were calculated using varying cut points. Results A total of 139 patients consented to participate inthe study. Plethysmography stage 1 or greater showed the highestsensitivity (sensitivity 94% and specificity 15%). Specificitywas optimized combining plethysmography stage 3 and thermometrystage 3 (specificity 98% and sensitivity 23%). Maximal diagnosticaccuracy was achieved by plethysmography alone setting the criteriafor a positive test as being stage 1 or greater (70%). Conclusions Neither plethysmography nor thermometry either aloneor in combination demonstrated sufficient sensitivity and specificityto serve as an objective correlate for SWS vascular stage. Allcombinations of plethysmography and thermometry showed a lowerspecificity than sensitivity indicating that the SWS may beless sensitive in detecting vascular pathology than the objectivetests.     

Ventilatory function of factory workers exposed to tea dust

A cross-sectional study was conducted in order to determinethe prevalence of respiratory symptoms and the effect on ventilatorycapacity in workers exposed to tea dust for at least five yearsduring the sifting process of tea manufacture compared to acontrol group of field workers who were not exposed to tea dustpreviously. Fifty-three subjects each in the study and controlgroups were matched for age, sex, ethnic group and height. Prevalenceof chronic respiratory symptoms was obtained by questionnaire.Spirometric measurements included forced vital capacity (FVC),forced expiratory volume in the first second (FEV_1.0) and forcedmid-expiratory flow rate (FEF_25–75%). The study grouphad a chest radiograph. The odds ratio for any chronic respiratorysymptom was 11.6 (95% confidence interval [Cl] = 3.7–39.4)in the study group. Mean values for the spirometric tests werelower in the study group; the differences in FEV_1.0 and FEF_25–75%were significant. Tuberculosis was not found in the study group,while one subject (2.4%) had radiological evidence of bronchiectasis.It may therefore be concluded that chronic tea dust exposurecauses increased prevalence of respiratory symptoms and a significantdegree of small airways obstruction.     

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.