Dust exposure and impairment of lung function at a small iron foundry in a rapidly developing country

OBJECTIVES—A cross sectional prospective study was carried out among iron foundry workers (exposed) and soft drink bottling and supply company workers (unexposed) to assess their occupational exposure to ambient respiratory dust in their work environment and its effect on their lung function profile.
PARTICIPANTS—Lung function was measured in 81 exposed and 113 unexposed workers. Personal respirable dust concentrations were measured for all the exposed and the unexposed workers. Information on respiratory signs and symptoms was also collected from the participants.
RESULTS—Among the exposed workers, midexpiratory flow (FEF_25-75), forced expiratory volume in 1 second (FEV₁), peak expiratory flow (PEF), FEV₁/FVC, and FEV₁/VC ratios were significantly lower whereas the vital capacity (VC) and forced vital capacity (FVC) were non-significantly higher. Job at the iron foundry was a significant predictor of lung function. Exposure to high concentration of respirable dust at the iron foundry was also a significant predictor. Workers working in high exposure areas (general works, furnace, continuous casting areas, and fabrication workshop) had lower lung function values than workers in medium and low exposure areas. Smoking did not enhance the effects of exposure to dust on lung function.
CONCLUSIONS—Exposure to respirable dust was higher among the iron foundry workers; and among these, general, furnace, rolling mill, and fabrication workers had higher exposures to dust than did workers in continuous casting, the mechanical workshop, and the bottling plant. Job type and exposure to dust were significant predictors of lung function. Implementation of industrial hygiene and proper and efficient use of personal protection equipment while at work could help to protect the respiratory health of industrial workers.


Keywords: lung function; dust exposure; foundry; smoking; personal protection     

Cumulative exposure to dust causes accelerated decline in lung function in tunnel workers

OBJECTIVES—To examine whether underground construction workers exposed to tunnelling pollutants over a follow up period of 8 years have an increased risk of decline in lung function and respiratory symptoms compared with reference subjects working outside the tunnel atmosphere, and relate the findings to job groups and cumulative exposure to dust and gases.
METHODS—96 Tunnel workers and a reference group of 249 other heavy construction workers were examined in 1991 and re-examined in 1999. Exposure measurements were carried out to estimate personal cumulative exposure to total dust, respirable dust, α-quartz, oil mist, and nitrogen dioxide. The subjects answered a questionnaire on respiratory symptoms and smoking habits, performed spirometry, and had chest radiographs taken. Radiological signs of silicosis were evaluated (International Labour Organisation (ILO) classification). Atopy was determined by a multiple radioallergosorbent test (RAST).
RESULTS—The mean exposure to respirable dust and α-quartz in tunnel workers varied from 1.2-3.6 mg/m³ (respirable dust) and 0.019-0.044 mg/m³ (α-quartz) depending on job task performed. Decrease in forced expiratory volume in 1 second (FEV₁) was associated with cumulative exposure to respirable dust (p<0.001) and α-quartz (p=0.02). The multiple regression model predicted that in a worker 40 years of age, the annual decrease in FEV₁ would be 25 ml in a non-exposed non-smoker, 35 ml in a non-exposed smoker, and 50-63 ml in a non-smoking tunnel worker (depending on job). Compared with the reference group the odds ratio for the occurrence of new respiratory symptoms during the follow up period was increased in the tunnel workers and associated with cumulative exposure to respirable dust.
CONCLUSIONS—Cumulative exposures to respirable dust and α-quartz are the most important risk factors for airflow limitation in underground heavy construction workers, and cumulative exposure to respirable dust is the most important risk factor for respiratory symptoms. The finding of accelerated decline in lung function in tunnel workers suggests that better control of exposures is needed.


     

Exposure to tremolite asbestos and respiratory health in Swedish dolomite workers

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


Keywords: asbestos tremolite; dolomite; lung function     

Respiratory health effects from exposure to carbon black: results of the phase 2 and 3 cross sectional studies in the European carbon black manufacturing industry

OBJECTIVES—To assess respiratory morbidity over several cross sectional phases in the European carbon black manufacturing industry.
METHODS—Participants completed an amended (and translated) MRC respiratory morbidity questionnaire with additional questions on previous exposures, job history, etc, and spirometry traces in each phase. Concurrent with the health outcome measures, personal exposure to inhalable dust was measured.
RESULTS—Percentage participation rose from 90% in phase 2 (19 factories) to 95% in phase 3 (16 factories). Exposure dropped slightly between the 2 and 3 phases; as did the prevalence of reporting symptoms. Percentage of predicted lung function volumes exceeded 100% for forced expired volume in 1 second (FEV₁) and forced vital capacity (FVC), whereas forced mid-expiratory flow (FEF_25%-75%) and FEV₁/FVC ratio were below 100% in both phases. The multiple linear and logistic regressions showed that carbon black had a significant effect on lung function and on most respiratory symptoms, respectively.
CONCLUSION—Both current and cumulative exposure to carbon black have a deleterious effect on respiratory morbidity. Due to the drop in exposure between phases 2 and 3, recent exposures seem to have less of an impact on the respiratory morbidity in the workers in phase 3 than those in phase 2.


Keywords: carbon black; respiratory morbidity; spirometry     

Crystalline silica exposure and lung cancer mortality in diatomaceous earth industry workers: a quantitative risk assessment

OBJECTIVE—To use various exposure-response models to estimate the risk of mortality from lung cancer due to occupational exposure to respirable crystalline silica dust.
METHODS—Data from a cohort mortality study of 2342 white male California diatomaceous earth mining and processing workers exposed to crystalline silica dust (mainly cristobalite) were reanalyzed with Poisson regression and Cox's proportional hazards models. Internal and external adjustments were used to control for potential confounding from the effects of time since first observation, calendar time, age, and Hispanic ethnicity. Cubic smoothing spline models were used to assess the fit of the models. Exposures were lagged by 10 years. Evaluations of the fit of the models were performed by comparing their deviances. Lifetime risks of lung cancer were estimated up to age 85 with an actuarial approach that accounted for competing causes of death.
RESULTS—Exposure to respirable crystalline silica dust was a significant predictor (p<0.05) in nearly all of the models evaluated and the linear relative rate model with a 10 year exposure lag seemed to give the best fit in the Poisson regression analysis. For those who died of lung cancer the linear relative rate model predicted rate ratios for mortality from lung cancer of about 1.6 for the mean cumulative exposure to respirable silica compared with no exposure. The excess lifetime risk (to age 85) of mortality from lung cancer for white men exposed for 45 years and with a 10 year lag period at the current Occupational Safety and Health Administration (OSHA) standard of about 0.05 mg/m³ for respirable cristobalite dust is 19/1000 (95% confidence interval (95% CI) 5/1000 to 46/1000).
CONCLUSIONS—There was a significant risk of mortality from lung cancer that increased with cumulative exposure to respirable crystalline silica dust. The predicted number of deaths from lung cancer suggests that current occupational health standards may not be adequately protecting workers from the risk of lung cancer.


Keywords: crystalline silica; cristobalite; lung cancer     

Exposure to silica and silicosis among tin miners in China: exposure-response analyses and risk assessment

OBJECTIVES—To investigate the risk of silicosis among tin miners and to investigate the relation between silicosis and cumulative exposure to dust (Chinese total dust and respirable crystalline silica dust).
METHODS—A cohort study of 3010 miners exposed to silica dust and employed for at least 1 year during 1960-5 in any of four Chinese tin mines was conducted. Historical total dust data from China were used to create a job exposure matrix for facility, job title, and calendar year. The total dust exposure data from China were converted to estimates of exposure to respirable crystalline silica for comparison with findings from other epidemiological studies of silicosis. Each worker''s work history was abstracted from the complete employment records in mine files. Diagnoses of silicosis were based on 1986 Chinese pneumoconiosis Roentgen diagnostic criteria, which classified silicosis as stages I-III—similar to an International Labour Organisation (ILO) classification of 1/1 or greater.
RESULTS—There were 1015 (33.7%) miners identified with silicosis, who had a mean age of 48.3 years, with a mean of 21.3 years after first exposure (equivalent to 11.0 net years in a dusty job). Among those who had silicosis, 684 miners (67.4%) developed silicosis after exposure ended (a mean of 3.7 years after). The risk of silicosis was strongly related to cumulative exposure to silica dust and was well fitted by the Weibull distribution, with the risk of silicosis less than 0.1% when the Chinese measure of cumulative exposure to total dust (CTD) was under 10 mg/m³-years (or 0.36 mg/m³-years of respirable crystalline silica), increasing to 68.7% when CTD exposure was 150 mg/m³-years (or 5.4 mg/m³-years of respirable crystalline silica). Latency period was not correlated to the risk of silicosis or cumulative dose of exposure. This study predicts about a 36% cumulative risk of silicosis for a 45 year lifetime exposure to these tin mine dusts at the CTD exposure standard of 2 mg/m³, and a 55% risk at 45 years exposure to the current United States Occupational Safety and Health Administration and Mine Safety and Health Administration standards of 0.1 mg/m³ 100% respirable crystalline silica dust.
CONCLUSIONS—A clear exposure-response relation was detected for silicosis in Chinese tin miners. The study results were similar to most, but not all, findings from other large scale exposure-response studies.


     

Symptoms, airway responsiveness, and exposure to dust in beech and oak wood workers

OBJECTIVES—To investigate the relation between levels of cumulative exposure to wood dust and respiratory symptoms and the occurrence of bronchial hyperresponsiveness among beech and oak workers.
METHODS—114 Male woodworkers from five furniture factories and 13 male unexposed controls were examined. The unexposed control group was supplemented by 200 male historical controls. Statistical analyses were performed excluding and including the historical controls. Dust concentration was measured by personal sampling methods. Cumulative exposure to dust was calculated for each woodworker by multiplying the duration of the work by the intensity of exposure (years.mg/m³). Bronchial hyperresponsiveness was assessed by the methacholine bronchial challenge test. Subjects were labelled methacholine bronchial challenge positive if forced expiratory volume in 1 second (FEV₁) fell by 20%. The linear dose-response slope was calculated as the last dose divided by the total dose given.
RESULTS—443 Dust samples were collected. The median cumulative exposure to dust was 110 years.mg/m³ with lower and upper quartiles at 70 and 160 years.mg/m³ Overall, no declines in FEV₁ and forced vital capacity (FVC) were found with increasing exposures. A dose-response relation was found between intensity of exposure on the one hand, and sore throat, increased prevalence of positive methacholine bronchial challenge tests, and steeper dose-response slope, on the other.
CONCLUSION—Exposure to oak and beech dust may lead to the development of sore throat and bronchial hyperresponsiveness.


Keywords: bronchial hyperresponsiveness; wood dust; beech; oak     

Prevalence of airway symptoms among hairdressers in Bergen, Norway

OBJECTIVE—To assess respiratory symptoms among hairdressers in Norway.
METHODS—The study was based on a questionnaire sent to 100 hairdressers (91% responding) and 95 office workers (84% responding). The questionnaire sought information about allergy, respiratory symptoms in the past year, and symptoms after exposures to different types of pollutants, working conditions, and smoking habits. A population based control group was established because the hairdressers and office workers differed in age and smoking habits.
RESULTS—The prevalence of respiratory symptoms in the past year did not differ significantly between hairdressers and office workers after adjusting for age, atopy, and smoking. The hairdressers over 40 years of age reported significantly more symptoms—such as wheezing and breathlessness—in the past year than the office workers of the same age. Compared with the population based control group, both hairdressers younger than 30 and those over 40 reported more symptoms—such as breathlessness in the past year. The oldest hairdressers reported such symptoms as wheezing and breathlessness more often than did the younger hairdressers. These differences in breathlessness were significant after adjusting for smoking and wheezing. The same trend was not found among the office workers. The hairdressers reported significantly more wheezing, breathlessness, runny eyes, and blocked or runny nose from exposure to hair dyes, permanent oils, bleaching powder, and other chemicals used in a hairdressing salon, compared with the office workers. Prevalence of symptoms during exposure to other types of generel pollutants was similar in the two groups.
CONCLUSIONS—Hairdressers are exposed to low levels of various irritating chemicals every day. The prevalences of acute symptoms related to the exposure of hairdressers to hairdressing chemicals are very high. Hairdressers, especially the oldest hairdressers, have more asthma-like symptoms than the control groups.


Keywords: hairdresser; allergy; asthma     

Sensitisation to enzymes in the animal feed industry

OBJECTIVES—To assess the prevalence of enzyme sensitisation in the animal feed industry.
METHODS—A cross sectional study was conducted in four animal feed factories, where several enzymes had been used in powder form for 7-9 years. Before this study, enzymes in liquid form had started to be used. Sensitisation to enzymes was examined by skin prick and radioallergosorbent (RAST) tests. Altogether 218 workers were tested; 140 people in various tasks in manufacturing, where exposure to various organic dusts and to enzymes was possible, and 78 non-exposed office workers. The workers were interviewed for work related respiratory and skin symptoms. Total dust concentrations were measured by a gravimetric method. The concentrations of protease and α-amylase were measured with catalytic methods and that of xylanase with an immunological method.
RESULTS—Ten workers (7%) were sensitised to enzymes in the exposed group of 140, whereas none were sensitised in the non-exposed group. Six of the sensitised people had respiratory symptoms at work: two of them especially in connection with exposure to enzymes. Enzyme concentrations in the air varied greatly: xylanase from less than 0.8 ng/m³ up to 16 ng/m³, α-amylase from less than 20 ng/m³ up to 200 ng/m³, and protease from less than 0.4 ng/m³up to 2900 ng/m³. On average, highest xylanase and α-amylase concentrations were found in the various manufacturing sites, whereas the highest protease concentrations were found in areas of high total dust.
CONCLUSIONS—Industrial enzymes may cause allergies in the animal feed industry. There is a need to assess exposure to enzymes at various phases of production, and to minimise exposures.


Keywords: animal feed; enzyme allergy; occupational exposure     

Epidemiological survey of workers exposed to inorganic germanium compounds

OBJECTIVES—To assess occupational exposure to inorganic germanium (Ge) in workers from a producing plant, and to assess the health of these workers, with a special focus on respiratory, kidney, and liver functions.
METHODS—Cross sectional study of 75 workers exposed to Ge and 79 matched referents. Exposure was characterised by measuring air and urine concentrations of the element during a typical working week, and health was assessed by a questionnaire, clinical examination, lung function testing, chest radiography, and clinical chemistry in serum and urine, including high and low molecular weight urinary proteins.
RESULTS—Airborne concentrations of Ge (inhalable fraction) ranged from 0.03 to 300 µg/m, which was reflected by increased urinary excretion of Ge (0.12-200 µg/g creatinine, after the shift at the end of the working week). Lung, liver, and haematological variables were not significantly different between referents and workers exposed to Ge. A slightly higher urinary concentration of high molecular weight proteins (albumin and transferrin) was found in workers exposed to Ge, possibly reflecting subclinical glomerular changes. No relation was found between the intensity or duration of exposure and the urinary concentration of albumin. No difference between referents and workers exposed to Ge was found for other renal variables.
CONCLUSIONS—Measurement of urinary Ge can detect occupational exposure to inorganic Ge and its compounds. It is prudent to recommend the monitoring of renal variables in workers exposed to Ge.


Keywords: inorganic germanium; occupational exposure; biological monitoring     

Erionite bodies and fibres in bronchoalveolar lavage fluid (BALF) of residents from Tuzköy, Cappadocia, Turkey

OBJECTIVES—The high incidence of malignant mesothelioma in some villages of Cappadocia (Turkey) is due to environmental exposure to erionite fibres. The aim was to evaluate the fibre burden in bronchoalveolar lavage fluid (BALF) from inhabitants of an erionite village and compare it with Turkish subjects with or without environmental exposure to tremolite asbestos.
METHODS—Ferruginous bodies (FBs) and fibres were measured and analyzed by light and transmission electron microscopy (TEM) in the BALF of 16 subjects originating from Tuzköy.
RESULTS—FBs were detected in the BALF of 12 subjects, with concentrations above 1 FB/ml in seven of them. Erionite was the central fibre of 95.7% of FBs. Erionite fibres were found in the BALF of all subjects, by TEM, and these fibres were low in Mg, K, and Ca compared with erionite from Tuzköy soil. The mean concentration of erionite fibres in BALF was similar to that of tremolite fibres in Turks with environmental exposure to tremolite. The proportion of fibres longer than 8 µm in BALF represented 35.6% for erionite compared with 14.0% for tremolite. The asbestos fibre concentrations in erionite villagers was not different from that in Turks without environmental exposure to tremolite.
CONCLUSION—Analysis of BALF gives information about fibre retention in populations environmentally exposed to erionite for whom data on fibre burden from lung tissue samples are scarce. This may apply to exposed Turks having emigrated to other countries.


Keywords: ferruginous body; asbestos body; environmental exposure; mesothelioma     

Reconstruction of occupational mercury exposures at a chloralkali plant

OBJECTIVE—To reconstruct historical workplace exposure to mercury (Hg) from 1956 to 1994 at a large chloralkali factory for use in a current epidemiology study of the factory.
METHODS—All job activities of the employees were classified into one of 16 exposure categories, and the dates of changes in the processes were identified. Exposures to Hg for each job category, at each period of the plant''s operation, were then reconstructed from several data sources. A job-time period-exposure matrix was created, and the individual exposures of former workers were calculated. Data on exposure to Hg in air were compared with modelled concentrations of Hg in air and data on urinary Hg of the employees.
RESULTS—Within an exposure category, concentrations of Hg in air were fairly constant for the first 20 years of the factory''s operation, but began to increase in the late 1970s. Employees working in the cell room had the greatest exposures to Hg. The exposure estimates had significant correlations (p<0.001) with the urinary data and were well within the modelled range of concentrations of Hg in air.
CONCLUSIONS—The highest exposures occurred from 1987 until the plant closed in early 1994 with some exposure categories having time weighted average exposures to Hg greater than 140 µg/m³.


     

Occupational exposure to carcinogens in the European Union

OBJECTIVES—To construct a computer assisted information system for the estimation of the numbers of workers exposed to established and suspected human carcinogens in the member states of the European Union (EU).
METHODS—A database called CAREX (carcinogen exposure) was designed to provide selected exposure data and documented estimates of the number of workers exposed to carcinogens by country, carcinogen, and industry. CAREX includes data on agents evaluated by the International Agency for Research on Cancer (IARC) (all agents in groups 1 and 2A as of February 1995, and selected agents in group 2B) and on ionising radiation, displayed across the 55 industrial classes. The 1990-3 occupational exposure was estimated in two phases. Firstly, estimates were generated by the CAREX system on the basis of national labour force data and exposure prevalence estimates from two reference countries (Finland and the United States) which had the most comprehensive data available on exposures to these agents. For selected countries, these estimates were then refined by national experts in view of the perceived exposure patterns in their own countries compared with those of the reference countries.
RESULTS—About 32 million workers (23% of those employed) in the EU were exposed to agents covered by CAREX. At least 22 million workers were exposed to IARC group 1 carcinogens. The exposed workers had altogether 42 million exposures (1.3 mean exposures for each exposed worker). The most common exposures were solar radiation (9.1 million workers exposed at least 75% of working time), environmental tobacco smoke (7.5 million workers exposed at least 75% of working time), crystalline silica (3.2 million exposed), diesel exhaust (3.0 million), radon (2.7 million), and wood dust (2.6 million).
CONCLUSION—These preliminary estimates indicate that in the early 1990s, a substantial proportion of workers in the EU were exposed to carcinogens.


     

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 µg/m³ 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 µg/m³ respectively, compared with United Kingdom users of latex powdered gloves,who had GM concentrations of 0.5 µg/m³. 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.


     

Risk of enzyme allergy in the detergent industry

OBJECTIVES—To assess the prevalence of enzyme sensitisation in the detergent industry.
METHODS—A cross sectional study was conducted in a detergent factory. Sensitisation to enzymes was examined by skin prick and radioallergosorbent (RAST) tests. 76 Workers were tested; 40 in manufacturing, packing, and maintenance, and 36 non-exposed people in management and sales departments. The workers were interviewed for work related respiratory and skin symptoms. Total dust concentrations were measured by a gravimetric method, and the concentration of protease in air by a catalytic method.
RESULTS—Nine workers (22%) were sensitised to enzymes in the exposed group of 40, whereas none were sensitised in the non-exposed group. All the sensitised people had symptoms at work; all had rhinitis and one had asthma.
Protease concentrations were generally <20 ng/m³, but occasional peak values up to 80 ng/m³ were detected in the packing and maintenance tasks, and high values of >1 µg/m³ in the mixing area.
CONCLUSION—Despite the use of encapsulated enzyme preparations, high enzyme concentrations in workplace air are possible, resulting in a higher risk of sensitisation than expected.


Keywords: detergent enzymes; occupational exposure; allergy     

Mortality experience among employees at a hydrometallurgical nickel refinery and fertiliser complex in Fort Saskatchewan, Alberta (1954-95)

OBJECTIVE—To study the mortality experience of workers at a hydrometallurgical nickel refinery and fertiliser complex in Fort Saskatchewan, Alberta, Canada.
METHODS—A total of 1649 male employees of Sherritt International who worked for at least 12 continuous months during the years 1954 to 1978 at the Fort Saskatchewan, Alberta hydrometallurgical nickel refinery and fertiliser complex were followed up for an additional 17 years. Mortality was ascertained from the Canadian mortality data base maintained by Statistics Canada and covered the years 1954-95. Statistics were analysed with Monson's computer program.
RESULTS—Total mortality, when compared with the Canadian population, was significantly below expectation. Fewer deaths were found for circulatory disease, ischaemic heart disease, respiratory disease, neoplasms, digestive cancer, and accidents, poisonings, and violence. Among the 718 men in the group exposed to nickel, there were no deaths due to nasal cavity or paranasal sinus cancer. Fewer deaths were found for all causes, circulatory disease, ischaemic heart disease, neoplasms and digestive cancer. Lower death rates were observed than expected for respiratory malignancies and cancer of the bronchus and lung.
CONCLUSION—No association was found in this study between exposure to nickel concentrate or metallic nickel in the hydrometallurgical refining process and the subsequent development of respiratory cancer.


Keywords: epidemiology; nickel workers; mortality     

Short term respiratory effects of acute exposure to chlorine due to a swimming pool accident

OBJECTIVE—Acute exposure to chlorine causes lung damage, and recovery may proceed slowly for several weeks. The short term respiratory effects of acute chlorine inhalation during a swimming pool accident were examined.
METHODS—A total of 282 subjects (134 children, aged <14 years) inhaled hydrogen chloride and sodium hypochlorite during an accident caused by a malfunction of the water chlorinating system in a community pool in Rome in 1998. Most people received bronchodilators and cortisone at the emergency room; five children were admitted to hospital. A total of 260 subjects (92.2%) were interviewed about duration of exposure (<3, 3-5, >5 minutes), intensity of exposure (not at all or a little, a moderate amount, a lot), and respiratory symptoms. Lung function was measured in 184 people (82 children) after 15-30 days. The effects of exposure to chlorine were analysed through multiple linear regression, separately in adults and in children.
RESULTS—Acute respiratory symptoms occurred among 66.7% of adults and 71.6% of children. The incidences were highest among those who had chronic respiratory disease and had a longer duration of exposure. In about 30% of the subjects, respiratory symptoms persisted for 15-30 days after the accident. Lung function levels were lower in those who reported a high intensity of exposure than in those who reported low exposure, both in children and in adults (mean (95% confidence interval (95% CI)) differences in forced expiratory volume in 1 second (FEV_1,) were −109 (−310 to 93) ml, and −275 (−510 to −40) ml, respectively).
CONCLUSION—Persistent symptoms and lung function impairment were found up to 1 month after the incident. Although community pool accidents happen rarely, the medical community needs to be alerted to the possible clinical and physiological sequelae, especially among susceptible people.


Keywords: accidental exposure; chlorine gas; lung function     

Low level exposure to cadmium and early kidney damage: the OSCAR study

OBJECTIVES—To study the dose-response relation between cadmium dose and renal tubular damage in a population of workers and people environmentally or occupationally exposed to low concentrations of cadmium.
METHODS—Early kidney damage in 1021 people, occupationally or environmentally exposed to cadmium, was assessed from cadmium in urine to estimate dose, and protein HC (α₁-microglobulin) in urine to assess tubular proteinuria.
RESULTS—There was an age and sex adjusted correlation between cadmium in urine and urinary protein HC. The prevalence of tubular proteinuria ranged from 5% among unexposed people to 50% in the most exposed group. The corresponding prevalence odds ratio was 6.0 (95% confidence interval (95% CI) 1.6 to 22) for the highest exposure group, adjusted for age and sex. Multiple logistic regression analysis showed an increasing prevalence of tubular proteinuria with urinary cadmium as well as with age. After adjustment to the mean age of the study population (53 years), the results show an increased prevalence of 10% tubular proteinuria (taking into account a background prevalence of 5%) at a urinary cadmium concentration of 1.0 nmol/mmol creatinine.
CONCLUSION—Renal tubular damage due to exposure to cadmium develops at lower levels of cadmium body burden than previously anticipated.


Keywords: cadmium; environmental; tubular damage     

Occupational exposure to cis-1,3-dichloropropene: biological effect monitoring of kidney and liver function

OBJECTIVES—To investigate the possible effects of occupational exposure to the nematocide cis-1,3-dichloropropene (cis-DCP) on function of the kidney and liver in the starch potato growing region in The Netherlands.
METHODS—The study involved 13 commercial application workers exposed to cis-DCP for 117 days, and 22 matched control workers. The inhalatory exposure of the application workers was estimated from biological monitoring data. All workers collected urine and serum samples before, during, and after the fumigation season for monitoring of variables for kidney and liver function. Renal effect variables were alanine aminopeptidase (AAP), N-acetyl-β-D-glucosaminidase (NAG), retinol binding protein (RBP), and albumin (ALB) in urine, and β₂-microglobulin (β₂M-S) and creatinine in serum (Creat-S). Liver variables were alanine aminotransferase (ALAT), aspartate aminotransferase (ASAT), γ-glutamyltranspeptidase (GGT), alkaline phosphatase (ALP), and total bilirubin (TBIL) in serum and the urinary ratio of 6-β-hydroxycortisol to free cortisol (βOHC/COR).
RESULTS—The geometric mean exposure of the application workers was 2.7 mg/m³ (8 hour time weighted average (8 hour TWA)); range 0.1-9.5 mg/m³. No differences were found between the values of the renal effect variables or the liver variables of the exposed group and the control group, except a lower urinary ratio of βOHC/COR in the exposed group. This was not considered to be related to the exposure to cis-DCP. No dose-effect relations were found between the exposure indices and the effect variables.
CONCLUSIONS—The present study does not provide evidence that occupational exposure to cis-DCP in the starch potato growing region causes adverse effects on the kidney or liver at 8 hour TWA exposure concentrations below 9.5 mg/m³ (2 ppm).


Keywords: cis-1,3-dichloropropene; occupational exposure; kidney; liver     

Impairment of colour vision in workers exposed to organic solvents

OBJECTIVES—To investigate loss of colour vision related to exposure to solvents and the role of three enzyme polymorphisms in modifying the risk in exposed workers.
METHODS—A sample was studied of 68 male dockyard workers and 42 male community controls with and without neuropsychological symptoms from a previous cross sectional study. Indices of cumulative and intensity based exposure to solvents were calculated for all subjects. Alcohol, drug, and smoking histories were obtained. Colour vision was tested by Lanthony D15d colour vision test. Genotype of glutathione S-transferase M1 and T1 and N-acetyltransferase 2 polymorphisms were determined.
RESULTS—The relation between impairment of colour vision and exposure to solvents was investigated with multiple regression techniques. Increasing annual exposure to solvents was significantly associated with reduced colour vision (p=0.029). Impairment of colour vision was not associated with neuropsychological symptoms as measured by the Q16 solvent symptom questionnaire. No significant association was found between acquired impairment of colour vision and genetic polymorphisms when GSTM1, GSTT1 or NAT2 phenotypes were included in the analyses.
CONCLUSIONS—Exposure to mixed solvents is associated with impairment in colour vision, the risk increases with increasing exposure. The risk of impairment of colour vision was not altered in this study by the presence of different GSTM1, GSTT1 or NAT2 polymorphisms.


Keywords: colour vision; organic solvents; genetic polymorphisms