Occupational causes of hypersensitivity pneumonitis: a systematic review and compendium.

BACKGROUND: Hypersensitivity pneumonitis (HP) is caused by a variety of antigens and low-molecular-weight chemicals, often through occupational exposure. Making a diagnosis of HP and identifying a cause are challenging. Cryptogenic cases are frequently reported, and missing or incomplete exposure histories can cause misclassification. AIMS: To provide an evidence-based compendium of sources of exposure and causes of HP for the clinician, through systematic review of medical literature. METHODS: Articles related to HP causative agents and occupational exposure were searched from the databases OVID Medline (1946 to October 2020) and EMBASE (1974 to October 2020). Abstracts and full texts of articles were screened by two reviewers. Data on causative antigens, occupational source of exposure and any associated eponymous name were extracted and grouped according to source of exposure. RESULTS: A total of 1790 articles were identified, from which 305 articles met the inclusion criteria. An additional 22 articles were identified from citation lists of the selected review articles. Sources of exposure identified for HP were sorted into 14 categories of work (agricultural, plant matter processing, wood, animal-related, foodstuff, food processing, metal processing, polymers, other manufacturing, chemicals, aerosolized water, service, waste and sewage and wind instruments). CONCLUSIONS: This work is a comprehensive list of occupational causative agents and exposures causing HP. Cases are grouped by source of exposure, allowing an immediately accessible compendium of causes for use during occupational exposure assessment, which could also form the basis for a clinical questionnaire.

Needlestick injuries among Malaysian healthcare workers.

BACKGROUND: Needlestick injury (NSI) is a significant occupational health issue among healthcare workers (HCWs). AIMS: To determine the national self-reported incidence and risk factors for NSI among Malaysian Ministry of Health (MOH) HCWs. METHODS: Using data from the MOH national sharps injury surveillance programme, information on reported NSIs over a 1-year period (2016) for different HCW subgroups were extracted and analysed. RESULTS: A total of 1234 NSI cases were reported in 2016, giving an overall incidence of 6 injuries per 1000 HCWs. Medical doctors recorded the highest incidence (21.1 per 1000 HCWs) followed by dental staff (7.5), pharmacy staff (4.2), nurses (3.7), medical assistants (3.4) and allied and auxiliary staff (1.0). Doctors had significantly increased risk of NSI compared with allied and auxiliary staff (relative risk [RR] = 20.7, 95% confidence interval [CI] 15.5-27.5), medical assistants (RR = 6.1, 95% CI 4.5-8.2), nurses (RR = 5.7, 95% CI 5.0-6.6), pharmacy staff (RR = 5.0, 95% CI 3.7-6.6) and dental staff (RR = 2.8, 95% CI 2.2-3.5). Significant differences were found in age and sharps- handling experience between occupational subgroups (P < 0.001 for both variables). Male employees had higher risk than females (RR = 1.33, 95% CI 1.18-1.50), with a significant difference seen in their sharps-handling experience (P < 0.01). Important risk factors included unsafe practices such as recapping of needles and their improper disposal. CONCLUSIONS: The national incidence of NSI amongst Malaysian HCWs was lower compared with other countries, but unsafe practices remain an important concern. There is a need to formulate, implement and monitor safe and consistent practices for the different healthcare professionals.

Complications after prominent ear correction: A systematic review of the literature.

BACKGROUND: There is great diversity in reported post-operative outcomes for otoplasty, with the incidence of haematoma or infection ranging from 0% to 15.6% and 0%-10%, respectively. With such variability, it is difficult to determine an overall 'average' incidence of common post-operative complications. METHODS: A systematic review of the most relevant medical databases was conducted for studies available in English published between January 1, 2000, and December 31, 2015. Using the dataset, pooled estimates for the incidence of the primary and secondary outcomes were calculated for all included studies. The primary outcome was haematoma and/or bleeding incidence, and the secondary outcomes included infection, skin/wound healing problems, suture-related problems, scarring, pain and itching, and revision surgeries/recurrence. Comparable sub-group analysis of studies was also performed using calculated pooled proportions. RESULTS: After screening, 28 articles involving 3493 patients were included in the study. Pooled proportions revealed that haematoma and/or bleeding incidence was 2.5% (95% CI: 1.4-3.8%), infection 0.8% (95% CI: 0.4-1.3%), skin/wound healing problems 3% (95% CI: 1.4-5.1%), suture-related problems 1.8% (95% CI: 0.8-3.2%), scarring 1.6% (95% CI: 0.8-2.6%), pain and itching 13% (95% CI: 5.4-23.1%) and revision surgeries/recurrence 5% (95% CI: 2.9-7.7%). CONCLUSIONS: By pooling proportions of reported complications, the results of this study could be useful in the personal audit of practice and will be a point of reference for comparing novel surgical techniques in the future.

Development of an occupational airborne chemical exposure matrix.

BACKGROUND: Population-based studies of the occupational contribution to chronic obstructive pulmonary disease generally rely on self-reported exposures to vapours, gases, dusts and fumes (VGDF), which are susceptible to misclassification. AIMS: To develop an airborne chemical job exposure matrix (ACE JEM) for use with the UK Standard Occupational Classification (SOC 2000) system. METHODS: We developed the ACE JEM in stages: (i) agreement of definitions, (ii) a binary assignation of exposed/not exposed to VGDF, fibres or mists (VGDFFiM), for each of the individual 353 SOC codes and (iii) assignation of levels of exposure (L; low, medium and high) and (iv) the proportion of workers (P) likely to be exposed in each code. We then expanded the estimated exposures to include biological dusts, mineral dusts, metals, diesel fumes and asthmagens. RESULTS: We assigned 186 (53%) of all SOC codes as exposed to at least one category of VGDFFiM, with 23% assigned as having medium or high exposure. We assigned over 68% of all codes as not being exposed to fibres, gases or mists. The most common exposure was to dusts (22% of codes with >50% exposed); 12% of codes were assigned exposure to fibres. We assigned higher percentages of the codes as exposed to diesel fumes (14%) compared with metals (8%). CONCLUSIONS: We developed an expert-derived JEM, using a strict set of a priori defined rules. The ACE JEM could also be applied to studies to assess risks of diseases where the main route of occupational exposure is via inhalation.

Anterior cruciate ligament reconstruction and service in the British Army.

BACKGROUND: In 2005, British Army recruiting policy was revised to permit applicants with a history of anterior cruciate ligament reconstruction (ACLR) to be accepted for an initial period of engagement. AIMS: To determine whether personnel with an ACLR history are more likely to be medically discharged due to further injuries and complications than those without. METHODS: A retrospective study of personnel commissioned or enlisted into the British Army between January 2006 and July 2009. ACLR cases were identified from personnel and medical records and were age and sex matched to randomly selected controls. Reasons for discharge were identified. RESULTS: A total of 69 cases and 140 controls were included. A significant increase in risk of medical discharge was found in those with ACLR (incidence risk ratio was 3.04; 95% confidence interval 1.24-7.45). Sixty-one per cent of cases experienced complications linked to their previous surgery. CONCLUSIONS: The current British Army policy on recruitment of those with a history of ACLR should be reviewed in terms of fitness for service and risk of foreseeable harm in these individuals.

Voice disorders in Nigerian primary school teachers.

BACKGROUND: The prolonged use or abuse of voice may lead to vocal fatigue and vocal fold tissue damage. School teachers routinely use their voices intensively at work and are therefore at a higher risk of dysphonia. AIMS: To determine the prevalence of voice disorders among primary school teachers in Lagos, Nigeria, and to explore associated risk factors. METHODS: Teaching and non-teaching staff from 19 public and private primary schools completed a self-administered questionnaire to obtain information on personal lifestyles, work experience and environment, and voice disorder symptoms. Dysphonia was defined as the presence of at least one of the following: hoarseness, repetitive throat clearing, tired voice or straining to speak. RESULTS: A total of 341 teaching and 155 non-teaching staff participated. The prevalence of dysphonia in teachers was 42% compared with 18% in non-teaching staff. A significantly higher proportion of the teachers reported that voice symptoms had affected their ability to communicate effectively. School type (public/private) did not predict the presence of dysphonia. Statistically significant associations were found for regular caffeinated drink intake (odds ratio [OR] = 3.07; 95% confidence interval [CI]: 1.51-6.62), frequent upper respiratory tract infection (OR = 3.60; 95% CI: 1.39-9.33) and raised voice while teaching (OR = 10.1; 95% CI: 5.07-20.2). CONCLUSIONS: Nigerian primary school teachers were at risk for dysphonia. Important environment and personal factors were upper respiratory infection, the need to frequently raise the voice when teaching and regular intake of caffeinated drinks. Dysphonia was not associated with age or years of teaching.

Protection afforded by controlled application of a barrier cream: a study in a workplace setting.

BACKGROUND: Skin protective creams (PCs) are used widely in industrial work environments to prevent irritant contact dermatitis. However, workplace studies remain equivocal in terms of their effectiveness, which may be partly owing to whether the PC remains on the skin. OBJECTIVES: To assess the practicability of using skin occlusion testing in a workplace as a method to determine whether PCs applied under controlled conditions can reduce skin damage against known irritants. This study also compares two methods of skin evaluation: clinical dermatological assessment and bioengineering techniques. METHODS: Daily occlusion testing for 1 h (over two consecutive weeks) was conducted in an engineering company on the volar forearm of 21 healthy volunteer engineers with sodium lauryl sulfate (SLS) and a PC that was used on site. The engineers conducted their normal work activities during the occlusion testing period. The skin areas tested were assessed using transepidermal water loss (TEWL), Chroma Meter and by visual dermatological scoring. RESULTS: Testing with PC and SLS together showed that PC does not prevent irritant contact dermatitis but significantly reduced skin damage compared with SLS alone (P < 0.01). The changes in skin were evident earlier with the biophysical measurements when compared with the dermatological assessment. CONCLUSIONS: Occlusion testing is a useful method for assessing the potential effectiveness of protective creams and can be used in a workplace without affecting work practices. TEWL and the Chroma Meter provide useful objective information and should be used in combination with dermatological examinations.

Hearing loss in British Army musicians.

BACKGROUND: Military musicians increasingly fulfil front line roles. Existing literature suggests that musicians are at greater risk of hearing loss than the general population. It is important to ascertain whether these findings apply to military musicians if they are to be placed in operational acoustically hazardous environments. AIMS: To compare hearing loss between groups of British Army musicians and with their administrative (non-musician) counterparts. METHODS: Routine health surveillance audiometric data for a group of military musicians were compared with military administrative staff during the first 8-12 years of their careers. Structured interviews were used to identify those meeting the study inclusion criteria (8 year minimum service, no significant, relevant medical history, no previous extraordinary loud noise exposure, service within study employment group throughout military career), and to clarify the instrument played. RESULTS: Eighty-four musicians and 44 administrators participated. Using the Health & Safety Executive's (HSE's) age- and gender-correcting system, 12 (14%) musicians and 9 (20%) non-musicians had a deterioration in hearing. The overall odds ratio for developing hearing loss in musicians was 0.65 (95% CI 0.25-1.68). Compared with woodwind instrumentalists, the odds ratio for hearing loss in brass instrumentalists was 2.00 (95% CI 0.85-3.44) and for percussionists 1.83 (95% CI 0.77-2.90). CONCLUSIONS: The findings suggest that military musicians are at no greater risk of hearing loss than their administrative counterparts after 8-12 years in service. This may represent a healthy-worker effect. There is no statistically significant differential risk of hearing loss between different instrumental groups.

Risks of cataract in Nigerian metal arc welders.

BACKGROUND: Occupational exposure to ultraviolet (UV) radiation from welding is considered a risk factor for cataract and other eye disorders, but the evidence for such effects is limited. AIMS: To identify any increased risk of developing cataract from metal arc welding and to investigate the associated risk factors. METHODS: A cross-sectional study was carried out on male welders and control subjects (not engaged in welding) from five fabrication and construction companies in Port Harcourt, Nigeria. A questionnaire was used to gather information regarding their demography and lifestyle, along with their occupational, medical and ocular histories. Cataract was identified by external examination and ophthalmoscopy. RESULTS: A total of 117 welders and 105 controls participated. There was no statistically significant increase in the risk of cataract in welders after adjusting for age, smoking status, family history of cataract, outdoor work and history of eye injury. There was a strong association between work-related eye-injury history and cataract. Only 60% of welders were wearing eye protection when the eye injury occurred. The majority of the eye injuries (72%) occurred during welding and grinding operations. CONCLUSIONS: The findings of this study suggest that the main occupational risk factor for cataract was a history of eye injuries. The role of UV (or optical) radiation appeared to be less important than impact eye injuries associated with welding-allied processes. It is therefore important that welders are provided with different types of eye protection and are informed about which type should be used, and when, so that they can be protected against optical and impact injuries.

Respiratory symptoms and lung function impairment in underground gold miners in ghana.

SUMMARY BACKGROUND: This is the first study in Ghana in the Obuasi gold mines where the silica content of the respirable dust is 10%, less than in previously studied gold mines, with only 23% of the miners having ever smoked. OBJECTIVES: The study was to assess the prevalence of respiratory impairment in the Ghanaian gold miner and to quantify the effects of the respirable dust on pulmonary function DESIGN: A cross sectional epidemiological study METHOD: The study was carried out using MRC respiratory symptoms questionnaire, spirometry, and personal respirable dust measurements. RESULTS: A total of 1236 miners were studied. The mean age was 39.7 +/-5.8 (SD) years with a mean of 12.6 +/- 6.7 (SD) years underground service and a mean total cumulative exposure to dust of 10.34 +/-5.61 (SD) mg.m(-3).years. The prevalence of chronic bronchitis was 21.2% and not clearly related to cumulative exposure. MRC breathlessness grade>/=2 was 31.3%, significantly related to cumulative respirable dust exposure after adjustment of age and smoking. There was however significant reduction in FEF(25-75%) with increasing dust exposure and an interaction with ever smoking. There was no correlation between cumulative exposure to respirable dust and FEV(1) % predicted in any group, suggesting that exposure to respirable silica at a mean level of 0.06 mg/m(3) had no deleterious effect on FEV(1) in a population with little tuberculosis, good housing and a low level of cigarette smoking. CONCLUSION: The prevalence of chronic bronchitis in the Ghanaian gold mine is related more to smoking than any occupational factors.

Low back pain in underground gold miners in ghana.

SUMMARY BACKGROUND: Biomechanical lumbo-spinal strain and intense physical work are the characteristic hallmarks of mining work. OBJECTIVES: To determine the prevalence and predisposing factors for Low Back Pain (LBP) among male underground gold miners at the Obuasi gold mine in Ghana. METHODS: This is a cross sectional study on 280 male underground gold miners from June to October 2001 with a structured questionnaire administered through interviews. RESULTS: The twelve months prevalence of low back pain among miners was 67%. The mean age of the workers was 40 years (+/- 5.6, ranging from 27 to 53 years). Increasing age was significantly associated with low back pain, (P=0.05) OR 2.07 (95% CI 0.99 to 4.34) after adjustment for smoking and occupation. Prevalence of LBP was highest among workers performing engineering (82%) duties. Heavy physical work (77%), was identified as a major cause of LBP, which could be prevented by the use of lifting aids (16%). CONCLUSION: The prevalence of low back pain in this group is comparable with that obtained from other studies in Africa and Europe. Training and education as a means of reducing LBP was suggested by just a few of the respondents.

Polycyclic aromatic hydrocarbon emissions from clinical waste incineration.

Since the introduction of the Environmental Protection Act in the UK, there are few reports of PAH emissions from clinical waste incinerators (CWIs) operating to improved performance standards. The main aim of this study is to determine PAH emissions from a state-of-the-art CWI focusing on the effects of reactive gases and operating variables on emissions. This was carried out by collection of stack samples over three phases of operation. At stack conditions, most PAHs are predicted to be in the vapour phase. Reactive losses of PAHs were closely correlated by rank with expected reactivities from laboratory studies. Estimates of emissions incorporating sampling losses were derived, although no correlation was found between PAH losses and the modest levels of reactive stack gases. PAH concentrations were one to two orders of magnitude lower than earlier reports from incinerators without effective air pollution control equipment (APCE). The low levels of carbon monoxide recorded were not correlated with any PAHs. This study demonstrates the impact of efficient combustion conditions and APCE on PAH emissions from a CWI.

Occupational exposure to diesel exhaust fumes.

There is currently no OEL for diesel fumes in the UK. This study reports parallel measurements of airborne levels of diesel fume pollutants in nine distribution depots where diesel powered fork-lift trucks (FLTs) were in use. Correlations between individual pollutants are assessed as well as their spatial distribution. Samples were collected on board FLTs and at background positions at nine distribution depots. Substances measured and the range of exposures by site were: respirable dust (n = 76) GM

Polycyclic aromatic hydrocarbons in solid residues from waste incineration.

Polycyclic aromatic hydrocarbons (PAH) levels in solid residues from clinical waste incineration were measured using HPLC with fluorescence detection. PAH mass emission rates and emission rates as a function of waste burned are also reported. For bottom ash, PAH levels and physical properties were found to be quite consistent. Levels of high molecular mass PAHs were comparable to levels previously reported in the literature when adjusted for differences in sample preparation techniques. However, levels of low molecular mass PAHs were considerably elevated in this study. Possible reasons for this finding include the composition of the waste, combustion conditions and methods of sample preparation. In contrast, no PAHs were found in fly ash, an unexpected finding which is probably attributable to matrix effects resulting from a surfeit of lime in the fly ash. Factors effecting the partitioning of PAHs and their environmental fate are also discussed.

Workers' understanding of chemical risks: electroplating case study.

BACKGROUND: There is limited research concerning how small companies in particular, respond to health and safety messages. AIMS: To understand individuals' knowledge and beliefs about chemical risks and to compare these with those of experts. METHODS: The use of chromic acid in particular, and also other chemicals associated with chrome plating were studied. All chromium plating firms were based in the West Midlands. The methodology involved initial face to face interviews (n = 21) with chromium platers, structured questionnaires (n = 84) to test the prevalence of beliefs identified in the interviews, an expert questionnaire, and a workshop to discuss findings. The responses of platers were compared with those of occupational health and safety experts. RESULTS: Although chromium platers appeared to understand the short term adverse effects of the chemicals to which they are exposed, their understanding of long term, or chronic effects appeared to be incomplete. They had good knowledge of acute effects based primarily on experience. Platers were aware of the hazardous nature of the chemicals with which they work, but did not draw distinction between the terms "hazards" and "risks". They had difficulties articulating the effects of the chemicals and how exposure might occur; although it is inappropriate to equate this with lack of knowledge. A significant minority of platers displayed deficiencies in understanding key technical terms used in Safety Data Sheets. CONCLUSIONS: This study provides a method which can be used to gain some understanding of workers' knowledge and beliefs about risks that they are exposed to in the workplace. The study also identifies gaps between the platers' knowledge and beliefs and those of experts. New risk information needs to be designed which addresses the information needs of platers using language that they understand.

Noise exposure and hearing loss among student employees working in university entertainment venues.

OBJECTIVES: Most studies to date on sound levels in entertainment establishments have concentrated on exposure levels for the attending public, rather than employees who may be at greater risk of hearing loss. Of particular concern are young employees. The aim of this pilot study was to (i) estimate typical sound levels in different areas where amplified music was played, (ii) measure temporary threshold shift (TTS) and (iii) estimate the dependence of hearing threshold shifts on measured noise levels. METHODS: This study focused on students working part-time (up to 16 h/week) in music bars and discotheques in a university entertainment venue. All 28 staff were invited to participate in the study. Pre- and post-exposure audiometry was used to determine hearing threshold at both high and low frequencies. Personal dosemeters and static measurements were made to assess noise levels and frequency characteristics. A questionnaire was used to determine patterns of noise exposure and attitudes to noise levels and hearing loss. RESULTS: Of the 28 student employees working in the three areas, 14 (50%) agreed to take part in the study, giving 21 pre- and post-shift audiograms. The mean personal exposure levels for security staff were higher than those of bar staff, with both groups exceeding 90 dB(A). The maximum peak pressure reading for security staff was 124 dB. Although TTS values were moderate, they were found to be highly significant at both low and high frequencies and for both ears. Twenty-nine per cent of subjects showed permanent hearing loss of more than 30 dB at either low or high frequencies. The correlation between TTS and personal exposure was higher at 4 kHz than the low and high frequencies. CONCLUSIONS: Contemporary music may be an important yet little considered contributor to total personal noise exposure, especially amongst young employees. Employees need to be better informed of risks of hearing loss and the need to report changes in hearing acuity. Suggestions are made on strategies for improving the assessment of noise exposure in entertainment venues.

Occupational asthma caused by chloramines in indoor swimming-pool air.

The first series of three workers who developed occupational asthma following exposure to airborne chloramines in indoor chlorinated swimming pools is reported. Health problems of swimmers in indoor pools have traditionally been attributed to the chlorine in the water. Chlorine reacts with bodily proteins to form chloramines; the most volatile and prevalent in the air above swimming pools is nitrogen trichloride. Two lifeguards and one swimming teacher with symptoms suggestive of occupational asthma kept 2-hourly measurements of peak expiratory flow at home and at work, analysed using the occupational asthma system (OASYS) plotter, and/or had specific bronchial challenge testing to nitrogen trichloride, or a workplace challenge. Air measurement in one of the pools showed the nitrogen trichloride levels to be 0.1-0.57 mg x m(-3), which was similar to other studies. Two workers had peak expiratory flow measurements showing occupational asthma (OASYS-2 scores 2.88 and 3.8), both had a positive specific challenge to nitrogen trichloride at 0.5 mg x m(-3) with negative challenges to chlorine released from sodium hypochlorite. The third worker had a positive workplace challenge. Swimming-pool asthma due to airborne nitrogen trichloride can occur in workers who do not enter the water because of this chloramine. The air above indoor swimming pools therefore needs to be assessed and managed as carefully as the water.

Occupational health research priorities in Malaysia: a Delphi study.

OBJECTIVES: As part of a consultancy project on occupational health, the Delphi method was used to identify research priorities in occupational health in Malaysia. METHODS: Participation was sought from government ministries, industry, and professional organisations, and university departments with an interest in occupational and public health. Two rounds of questionnaires resulted in a final list of priorities, with noticeable differences between participants depending on whether they worked in industry or were from government organisations. RESULTS: The participation rate of 71% (55 of 78) was obtained for the first questionnaire and 76% (72 of 95) for the second questionnaire. The participants identified occupational health problems for specific groups and industries as the top research priority area (ranked as top priority by 25% of participants). Ministry of Health participants placed emphasis on healthcare workers (52% ranking it as top priority), whereas those from industry identified construction and plantation workers as groups, which should be accorded the highest priority. Evaluation of research and services was given a low priority. CONCLUSIONS: The priorities for occupational health determined with the Delphi approach showed differences between Malaysia, a developing country, and findings from similar European studies. This may be expected, as differences exist in stages of economic development, types of industries, occupational activities, and cultural attitudes to occupational health and safety. Chemical poisonings and workplace accidents were accorded a high priority. By contrast with findings from western countries, workplace psychosocial problems and musculoskeletal injuries were deemed less important. There also seemed to be greater emphasis on adopting interventions for identified problems based on experience in other countries rather than the need to evaluate local occupational health provisions.

Sensitisation to natural rubber latex: an epidemiological study of workers exposed during tapping and glove manufacture in Thailand.

OBJECTIVES: To estimate the prevalence of sensitisation to natural rubber latex in latex tappers and latex glove factory workers, and to relate this to airborne exposure to latex. METHODS: Five hundred workers employed in three latex glove factories, 314 tappers, and 144 college students (control group) were studied. The workers in the glove factories were classified into three exposure groups; high, moderate, and low. Personal exposures to natural rubber latex aeroallergens were measured by immunoassay. Symptom questionnaires and skin prick tests with latex allergens (Stallergènes 1:200 w/v) and other common environmental allergens were performed. The criterion for positivity was a wheal reaction at least 3 mm in diameter greater than that to a diluent control. RESULTS: The geometric mean (GM) concentration of latex in air was 15.4 microg/m(3) for those employed in glove stripping, glove inspections, and packing of powdered gloves. The moderate exposure glove manufacturing group and the tappers had GM concentrations of 2.3 and 2.4 microg/m(3) respectively, compared with United Kingdom users of latex powdered gloves,who had GM concentrations of 0.5 microg/m(3). The prevalence of sensitisation to latex in the tappers and latex glove factory workers was 1.3% and 1.7% respectively. No positive cases were found among the college students. Workers who showed a positive skin prick test to latex were more likely to be atopic. Work related respiratory and dermatological symptoms were found in about 20% of each population studied, but were not related to the presence of positive latex prick tests. CONCLUSIONS: This study suggests that in the Thai latex industries, latex sensitisation is rare despite high concentrations of airborne exposure and is less prevalent than in the healthcare sector in Europe where skin exposure is greater.

Natural rubber latex aeroallergen exposure in rubber plantation workers and glove manufacturers in Thailand and health care workers in a UK hospital.

OBJECTIVES: To estimate personal airborne natural rubber latex (NRL) concentrations for three occupational exposure groups; rubber plantation workers and NRL glove manufacturers in Thailand and health care workers in the UK. To utilise these data to classify the populations into appropriate exposure groups for the exposure-response analysis in the epidemiological study on latex allergy. METHODS: Two rubber plantations (110 workers), three NRL glove manufacturing factories (583 workers) in Thailand and one UK hospital (490 workers) were selected for the study. A preliminary workplace survey was carried out at each workplace in order to assign job titles subjectively in to high, moderate or low exposure groups for the purpose of sample selection. Between 5 and 20% of workers from each group for the three populations were then selected randomly for personal measurement of latex airborne allergens. Personal sampling was conducted using a 25 mm PTFE filter loaded in to an IOM sampling head at 2 l. min(-1). NRL aeroallergens were measured by an inhibition assay with NRL-specific IgE antibodies from NRL-sensitised people. RESULTS: A total of twenty-two personal samples were collected from plantation workers, sixty-one samples from the glove manufacturer employees and twenty seven from health care workers. The highest geometric mean (GM) NRL aeroallergen concentration was found in the glove manufacturing factories (7.3 microg m(-3)), followed by the rubber plantations (2.4 microg m(-3)) and the UK hospital (0.46 microg m(-3)). Amongst the NRL glove factories, the NRL aeroallergen concentrations were highest for those conducting the following tasks; glove stripping, glove inspections and packing of powdered gloves. The GM NRL aeroallergen for these tasks were in the range of 12.9 to 17.8 microg m(-3). CONCLUSIONS: In the process from tapping and manufacture of latex gloves through to their use the highest exposure to NRL aeroallergens is likely to occur in the manufacturing factories. Exposure to aeroallergens for the plantation workers was considered to be moderate and that of health care workers to be low.