Work with chemicals on deck of Norwegian chemical tankers

Summary The chemical environment on deck of Norwegian chemical tankers in 1985/1986 is described using information obtained from an interview of 85 seamen. The seamen are exposed to vapours from volatile chemicals during several working operations, such as loading, unloading and cleaning of the tanks. The major exposure is probably to organic solvents and other hydrocarbon compounds, both in the cargo and in the chemicals used in the cleaning processes. Captains experience almost no chemical exposure. Mates, pumpmen and able seaman may receive exposure of a similar kind and magnitude, but there are individual differences within each group of seamen. The eldest seamen seem to be more exposed to chemicals than the younger. Symptoms of acute intoxication occur in 35% of the seamen, related to work with organic solvents, to tank cleaning work and to insufficient use of protective respiratory equipment. Improvements of the chemical environment on board are recommended, to prevent acute and chronic effects of volatile chemical compounds. Better information concerning chemical hazards and prevention of these on chemical tankers seem to be of major importance:     

Acute nonlymphatic leukemia among deck officers on coastal tankers: a report of two cases

Deck officers on coastal tankers may be exposed to high concentrations of cargo vapors during loading and tank-cleaning operations. Two cases of acute nonlymphatic leukemia are described. Both men had worked as chief officers on coastal tankers transporting benzene and other petroleum products.     

Symptoms, lung and liver function, blood counts, and genotoxic effects in coastal tanker crews

 Objective The deck crew on tankers can be exposed to high concentrations of benzene and other chemicals during loading, unloading and tank-cleaning operations. The objective of this study was to investigate whether genotoxic or other early health effects of cargo vapour exposure could be detected in coastal tanker crews. Methods The association between exposure to cargo vapours and clinical symptoms and signs, spirometry, blood cell count, blood tests for liver function, and the frequency of micronuclei and sister chromatid exchanges in peripheral lymphocytes was studied in a cross-sectional investigation of 107 male crew members (66 deck crew and 41 others) on ten coastal tankers. Results Seven of the tankers had automatic cargo level gauging systems but some of the ships still had open hatches during loading and unloading operations. Acute symptoms such as headache, nausea, vertigo, fatigue and dizziness after loading or tank-cleaning operations were reported by 56 of the 66 deck crew members (85%). Irritation of the mucous membrane in eyes and upper respiratory tract by cargo vapours were also common in this group. Obstructive symptoms were more common in the group with the highest exposure to cargo vapours but persistent effects on lung function (vital capacity and forced expiratory volume in l s), nervous system, liver enzymes or blood counts were not found. The frequency of micronuclei after mitotic stimulation with phytohaemagglutinin was higher among the deck crew (mean 4.2, SEM 0.40) than in other crew members (mean 3.6, SEM 0.35), although the difference was not statistically significant. We found no association between exposure and the frequency of sister chromatid exchanges or micronuclei after stimulation with pokeweed mitogen. Conclusion This study indicates that exposure to cargo vapours in coastal tanker crews may cause symptoms in the respiratory and nervous systems. Received: 24 July 1996/Accepted: 20 September 1996     

Cancer incidence among Danish seafarers: a population based cohort study

Aims: Seafarers aboard oil and chemical tankers may be exposed to many chemicals, including substances like benzene that are known to be carcinogenic. Other seafarers are exposed to engine exhaust, different oil products, and chemicals used aboard and some years ago asbestos was also used extensively in ships. The aim of this study was to study cancer morbidity among Danish seafarers in relation to type of ship and job title. Methods: A cohort of all Danish seafarers during 1986–1999 (33 340 men; 11 291 women) registered by the Danish Maritime Authority with an employment history was linked with the nationwide Danish Cancer Registry and followed up for cancer until the end of 2002. The number of person years at risk was 517 518. Standardised incidence ratios (SIR) were estimated by use of the corresponding national rates. Results: The SIR of all cancers combined was higher than expected: 1.26 (95% CI 1.19 to 1.32) for men and 1.07 (95% CI 0.95 to 1.20) for women. This was mainly due to an excess of cancer of the larynx, lung, tongue, mouth, pharynx, oesophagus, pancreas, kidney, urinary bladder, colon, and bone as well as skin melanomas among men (the three latter borderline significantly increased), and an excess of cancer of the lung, rectum, and cervix uteri among women. The differences in risk pattern for lung cancer between the different job categories among men ranged in terms of SIR from 1.2 (95% CI 0.9 to 1.7) (engine officers) to 2.3 (1.6 to 3.3) (engine room crew), and 4.1 (2.1 to 7.4) among maintenance crew. Non-officers had a 1.5 times higher lung cancer risk than officers. No increased occurrence of all lymphatic and haematopoietic malignancies combined was found for employees on tankers, but the number of cases was limited to a total of 7. Conclusions: Danish seafarers, especially men, face an increased overall cancer risk, in particular a risk for lung cancer and other tobacco associated cancers.     

Occupational exposure of deck crews to carcinogenic agents on crude oil tankers

Occupational exposure to carcinogenic agents on the decks on six Norwegian crude oil tankers was examined in five harbors. The purpose of the study was to evaluate the need for improving the working environment on deck on these tankers. Technical arrangments and the work itself on the deck were observed during loading or unloading. Occupational monitoring was performed by active sampling of benzene, polyaromatic hydrocarbons, and some aldehydes. The crew answered a questionnaire concerning their work, use of protective equipment, and occurrence of acute symptoms. The levels of air-borne carcinogenic agents were low, probably due to closed loading systems on all tankers. However, the seamen reported discomfort during the work that may be related to other chemical agents in the cargo. The seamen were frequently painting with lead chromate paint without using personal protective equipment. This type of chemical exposure should be evaluated.     

Testicular cancer among Swedish pulp and paper workers

BACKGROUND: The incidence of testicular cancer has increased in recent decades. The aims of the present study were to elucidate whether Swedish paper and pulp mill workers had an increased incidence of testicular cancer, and to investigate whether certain occupational groups within the pulp and paper mill workforce were at increased risk. METHODS: The study was based on the Swedish Cancer Environment Register, which links the incidence of cancer for the period 1971-1990 with 1960 and 1970 National Census data on specific industries and occupations for all employed subjects in Sweden. RESULTS: Among maintenance workers employed both in 1960 and in 1970 in paper mills there was an increased risk for testicular cancer (standardized incidence ratio (SIR) 7.4, 95% confidence intervals (CI) 1.5-22), especially for seminomas (SIR 10.1, 95% CI 2.1-29). Maintenance workers were also at increased risk when analyzing workers employed in 1960, 1970, or both years. CONCLUSIONS: This study indicates an increased risk for testicular cancer, especially seminomas, among maintenance workers, but not among process workers, in Swedish paper mills.     

An industry wide mortality study of chemical workers occupationally exposed to benzene. I. General results

The cohort (7676) of this historical prospective study consisted of a group of male chemical workers from seven plants who had been occupationally exposed (continuously or intermittently) to benzene for at least six months and a comparison group of male chemical workers from the same plants who had been employed for at least six months during the same period but were never occupationally exposed to benzene. The observed mortality of the cohort, by cause, was compared with the expected based on the US mortality rates, standardised for age, race, sex, and calendar time. Standardised mortality ratios (SMRs) from all lymphatic and haematopoietic (lymphopoietic) cancer combined, leukaemia, non-Hodgkin's lymphoma (lymphosarcoma, reticulosarcoma, and other lymphoma), and non-Hodgkin's lymphopoietic cancer (non-Hodgkin's lymphoma and leukaemia) for the exposed group were slightly, but not significantly, raised above the national norm. These SMRs were considerably higher than those in the comparison group. When the group with no occupational exposure was used for direct comparison, the continuously exposed group experienced a relative risk from lymphopoietic cancer of 3.20 (p less than 0.05). Furthermore, the Mantel-Haenszel chi-square showed that the association between continuous exposure to benzene and leukaemia was statistically significant (p less than 0.05).     

An industry wide mortality study of chemical workers occupationally exposed to benzene. I. General results.

The cohort (7676) of this historical prospective study consisted of a group of male chemical workers from seven plants who had been occupationally exposed (continuously or intermittently) to benzene for at least six months and a comparison group of male chemical workers from the same plants who had been employed for at least six months during the same period but were never occupationally exposed to benzene. The observed mortality of the cohort, by cause, was compared with the expected based on the US mortality rates, standardised for age, race, sex, and calendar time. Standardised mortality ratios (SMRs) from all lymphatic and haematopoietic (lymphopoietic) cancer combined, leukaemia, non-Hodgkin's lymphoma (lymphosarcoma, reticulosarcoma, and other lymphoma), and non-Hodgkin's lymphopoietic cancer (non-Hodgkin's lymphoma and leukaemia) for the exposed group were slightly, but not significantly, raised above the national norm. These SMRs were considerably higher than those in the comparison group. When the group with no occupational exposure was used for direct comparison, the continuously exposed group experienced a relative risk from lymphopoietic cancer of 3.20 (p less than 0.05). Furthermore, the Mantel-Haenszel chi-square showed that the association between continuous exposure to benzene and leukaemia was statistically significant (p less than 0.05).     

Case-control study on the association between a cluster of childhood haematopoietic malignancies and local environmental factors in Aalsmeer, The Netherlands.

STUDY OBJECTIVE AND DESIGN--In Aalsmeer, a horticultural community near the main international airport in The Netherlands, a more than fourfold increase in the incidence of haematopoietic malignancies in young people was observed between 1980 and 1985. In a population based case-control study, the association with local environmental factors was investigated. PARTICIPANTS--For each patient younger than 40 years of age (n = 14) diagnosed between 1975 and 1989, four age and sex matched controls were selected via local general practitioners. METHODS--All parents of patients and controls completed a questionnaire on their lifestyle, living conditions, and health, for several years preceding each individual diagnosis. Odds ratios (ORs) with 95% confidence intervals (CI) were calculated, matched, and, if necessary, stratified for neighbourhood. MAIN RESULTS--Increased ORs were recorded for intensive use of petroleum products and pesticides by the patients themselves and their fathers: OR petroleum products: 8.0 (95% CI 2.2, 129.9) and 9.0 (1.0, 66.1) respectively; OR pesticides: 6.0 (0.6, 49.3) and 3.2 (1.0, 10.1) respectively. Swimming in a local pond was also significantly associated with the disease: OR = 5.3 (1.3, 17.4). In the 1970s this pond had been polluted by petroleum products and pesticides. CONCLUSIONS--The increased incidence of childhood haematopoietic malignancies in Aalsmeer may have been associated with several specific local environmental factors. Interpretation of the results, however, should take into account the fact that confidence intervals were wide because of the limited number of cases.     

Gliomas among men employed in the Swedish pulp and paper industry

OBJECTIVES: This study investigated whether previous findings of an increased risk of gliomas among workers in some pulp and paper mills could be confirmed for all Swedish pulp and paper mill workers and whether the increase could be attributed to certain occupational groups. METHODS: The study was based on the Swedish Cancer Environment Register, which links the incidence of cancer from 1971 to 1990 and the 1960 and 1970 census data on codes of occupation and industry for the whole population. Standardized incidence ratios (SIR) were used to estimate the risks for men in different occupations in pulp (N = 28,142) and paper (N = 39,169) mills in 1960, 1970 or both years as compared with those of all gainfully employed men in Sweden. RESULTS: Maintenance workers employed in pulp or paper mills in 1960, 1970 or both years, as well aspulp workers, showed an increased incidence of gliomas in 1971-1990 [SIR 1.5, 95% confidence interval (95% CI) 1.1-2.1 and SIR 1.5,95% CI 1.0-2.2, respectively], whereas the incidence among process workers in paper mills was lower than expected (SIR 0.6, 95% CI 0.3-0.9). Taken together, all employed men in the pulp mill industry had an increased incidence of gliomas (SIR 1.3, 95% CI 1.0-1.7). CONCLUSIONS: Pulp mill workers, but not paper mill workers, were found to have more gliomas in 1971-1990 than expected. There was an increased risk of gliomas among maintenance workers in both pulp and paper mills. Few risk factors for brain tumors are recognized, and the causes of the increase are not obvious.     

Cancer incidence of workers in the Swedish petroleum industry.

OBJECTIVES: To estimate the risk of cancer due to occupational exposure to petroleum products in the Swedish transport and refinery industries. METHODS: In a retrospective cohort study the cancer incidence in 4128 men and 191 women, who had worked for at least one year in the petroleum industry, was compared with the incidence in the general population. The job titles and employment times for each person were found in personal files in the industries. The men had on average worked in jobs exposed to petroleum for 11.6 years at the end of the observation period. The cases of cancer were identified by record linkage with the Swedish cancer register. RESULTS: In total there were 146 cases of cancer v 157.6 expected (standardised mortality ratio (SMR) 0.93 90% confidence interval (90% CI) 0.80 to 1.1). Operators at refineries had an increased risk of leukaemia (6 cases v 1.7 expected, 90% CI of relative risk (RR) 1.5 to 7.0). Five of the six cases had started to work at the refineries in the 1950s or later. No other significantly increased risk of cancer was found. Distribution workers had a decreased incidence of lung cancer (no cases, 90% CI of RR 0 to 0.4). CONCLUSIONS: Operators at Swedish refineries had an increased risk of leukaemia. A possible cause is exposure to benzene. There was no increased risk of leukaemia in distribution workers. Distribution workers had a decreased risk of lung cancer.     

Exposure of the deck crew to carcinogenic agents on oil product tankers

Work on deck on eight oil product tankers was examined. The purpose was to evaluate the need for improvement of the working environment to reduce the risk of occupational cancer. Benzene, polyaromatic hydrocarbons (PAHs) and organic lead compounds were sampled, and the crew answered a questionnaire on acute health effects. By area monitoring, benzene was generally found to be in the range from the detection limit, of 0.01 ppm, up to 1.15 ppm, but one tanker which loaded gasoline with the hatches open had levels up to 55 ppm. Personal monitoring showed exposure levels in the range 0.01–1.15 ppm. The PAH-levels and the levels of organic lead were low. No seamen were observed using respiratory protective equipment. Central nervous system symptoms were reported by the crew with the highest exposures to benzene although benzene may not be the only cause. The exposure to benzene and other hydrocarbons on the deck of oil product tankers ought to be reduced.     

Leukemia risk associated with low-level benzene exposure

BACKGROUND: Men who were part of an Australian petroleum industry cohort had previously been found to have an excess of lympho-hematopoietic cancer. Occupational benzene exposure is a possible cause of this excess. METHODS: We conducted a case-control study of lympho-hematopoietic cancer nested within the existing cohort study to examine the role of benzene exposure. Cases identified between 1981 and 1999 (N = 79) were age-matched to 5 control subjects from the cohort. We estimated each subject's benzene exposure using occupational histories, local site-specific information, and an algorithm using Australian petroleum industry monitoring data. RESULTS: Matched analyses showed that the risk of leukemia was increased at cumulative exposures above 2 ppm-years and with intensity of exposure of highest exposed job over 0.8 ppm. Risk increased with higher exposures; for the 13 case-sets with greater than 8 ppm-years cumulative exposure, the odds ratio was 11.3 (95% confidence interval = 2.85-45.1). The risk of leukemia was not associated with start date or duration of employment. The association with type of workplace was explained by cumulative exposure. There is limited evidence that short-term high exposures carry more risk than the same amount of exposure spread over a longer period. The risks for acute nonlymphocytic leukemia and chronic lymphocytic leukemia were raised for the highest exposed workers. No association was found between non-Hodgkin lymphoma or multiple myeloma and benzene exposure, nor between tobacco or alcohol consumption and any of the cancers. CONCLUSIONS: We found an excess risk of leukemia associated with cumulative benzene exposures and benzene exposure intensities that were considerably lower than reported in previous studies. No evidence was found of a threshold cumulative exposure below which there was no risk.     

An updated cohort mortality study of workers exposed to styrene in the reinforced plastics and composites industry.

Mortality data have been updated for a further 12 years for a cohort of workers in the reinforced plastics and composites industry with exposures to styrene monomer and other chemicals. The cohort consisted of 15,826 male and female employees who were exposed to styrene for at least six months between 1948 and 1977 at 30 participating manufacturing plants in the United States. A total of 1628 deaths were reported during the extended observation period, 1948-89. Mortality from several causes showed significant increases--namely, all causes, all cancers, oesophageal cancer, lung cancer, cancer of the cervix uteri, cancer of other female genital organs, hypertensive heart disease, certain non-malignant respiratory diseases, motor vehicle accidents, and homicides. When, however, mortality data were examined in terms of duration of employment, durations of styrene exposure, and cumulative styrene exposure no upward trend was detected in any of these causes of death. Most of the increases in mortality were among workers who were employed for only six months to a year or who had very low cumulative exposure (< 10 ppm-years). Therefore, the increased mortality was not likely to be related to exposure to styrene. Several explanations for the increased mortality are offered, including low socioeconomic class, smoking, and lifestyle factors characteristic of short term workers. There was no increased mortality from lymphatic and haematopoietic cancers overall or from any specific haematological malignancies. In particular, no increase in mortality from non-Hodgkin's lymphoma, Hodgkin's disease, multiple myeloma, or leukaemia was found. Furthermore, detailed exposure-response analyses did not show any relation between exposure to styrene and any of these haematological malignancies. The lack of an exposure-response relation further supports the conclusion that workers in the reinforced plastics industry in this study did not experience any increased risk of lymphatic and haematopoietic cancers as a result of their exposure to styrene.     

Railways and asbestos in Japan (1928-1987)--epidemiology of pleural plaques, malignancies and pneumoconioses-

Asbestos has been an indispensable insulating material for railway industries, especially steam locomotives (SLs). This review (1928-1987) consists of three parts. 1) Pleural plaques: Since the 1970s, pleural plaques have been regarded as evidence of past asbestos inhalation, and more recently recognized as a risk factor of asbestos-related malignancies. For diagnostic criteria on plain radiographs, the modified ILO 1980 International Classification of Radiographs of Pneumoconioses was used. Most cases had pleural plaques with normal lungs. Large plant workers showed a significantly higher rate of plaques than workers in smaller plants. Bilateral plaques were dominant followed by the left, then the right lung, and chest wall plaques were dominant over the diaphragm. The manifestation of pleural plaques was more correlated to years since the onset of the asbestos exposure than the sum of asbestos work years, although the result was not significant. The boilermen of railway ferry steamers had a significantly higher plaque rate than other seamen. CT studies on plaques started in 1978. 2) Asbestos-related malignancies: Five retrospective cohort studies 1960-1970 were made on primary lung cancer incidence and mortality among 350,000 active railway men with smoking information. The follow-up period was 20 yr at the longest. Almost all plant workers showed a tendency of higher incidence or mortality than the controls. Two cases of mesothelioma were reported in 1980. 3) Pneumoconioses: Most studies (1928-1975) had relatively low prevalence rates among SL-related workers.     

Non-Hodgkin's lymphoma and exposure to benzene in a multinational cohort of more than 308,000 petroleum workers, 1937 to 1996

Petroleum workers are exposed to benzene or benzene-containing petroleum products. As such, studies of these workers provide an opportunity for investigating the relationship between benzene and non-Hodgkin's lymphoma (NHL). However, few cohort studies of petroleum workers report results of NHL separately. One reason is that NHL is usually grouped with other lymphopoietic cancers in the analysis. Another reason is the relatively small number of NHL cases in some studies. To determine the risk of NHL in petroleum workers, we identified 26 cohorts of petroleum workers in the United States, the United Kingdom, Canada, Australia, Italy, and Finland. Authors of the original studies were contacted, and data on the number of observed deaths and person-years of observation were requested. Data from these studies were reviewed individually as well as combined in a pooled analysis (meta-analysis). In particular, results for individual cohorts, most of which had never been reported before, were presented. The combined multinational cohort consisted of more than 308,000 petroleum workers (6.6 million person-years), and the observation period covered an interval of 60 years from 1937 to 1996. A total of 506 NHL deaths were observed, compared with 561.68 expected. The standardized mortality ratio was 0.90 and the 95% confidence interval was 0.82 to 0.98. Analyses were performed by type of facility and industrial process. Stratum-specific standardized mortality ratios (95% confidence intervals) were 0.96 (0.86 to 1.07) for US refinery workers, 1.12 (0.90 to 1.37) for non-US refinery workers, 0.64 (0.50 to 0.82) for product (gasoline) distribution workers, and 0.68 (0.47 to 0.95) for crude oil workers. When individual cohorts were stratified by length of observation, no pattern was detected. In general, exposure levels before 1950 were much higher than thereafter. However, analysis of workers by hire date (< 1950, > or = 1950) revealed no difference in NHL mortality. Furthermore, none of the individual studies showed significant exposure-response relations. In summary, results from individual studies, as well as from the pooled analysis, indicated that petroleum workers were not at an increased risk of NHL as a result of their exposure to benzene or other benzene-containing petroleum products in their work environment. This conclusion was supported by cohort studies of workers in other industries who were exposed to benzene as well as by population-based case-control studies of NHL and occupational exposures.     

Haematological malignancies in childhood in Croatia: Investigating the theories of depleted uranium, chemical plant damage and ‘population mixing’

Some of potential causes proposed to explain the reported increase of haematological malignancies in childhood during or after the war period in several countries include depleted uranium, chemical pollution and population mixing theory. The aim of this study was to define the population of Croatian children aged 0-14 years who were potentially exposed to each of those risks during the war and to investigate any possible association between the exposure and the incidence of haematological malignancies. The authors analyzed the data reported by the Cancer Registry of Croatia during the pre-war period (1986-1990), war period (1991-1995) and post-war period (1996-1999). In the group of 10 counties potentially exposed to depleted uranium and two counties where chemical war damage occurred, no significant difference in incidence of the studied haematological malignancies was noted in comparison to pre-war period. The incidence of lymphatic leukaemia significantly increased in four counties where population mixing had occurred during the war period, supporting the 'mixing theory'. In those counties, the incidence of Hodgkin's lymphoma decreased during and after the war. In Croatia as a whole, decreases in incidence of myeloid leukaemias during war and non-Hodgkin lymphoma after the war were noted.     

Lymphohaematopoietic cancer risk among chemical workers exposed to benzene

Aims: To determine cause specific mortality in a cohort of 2266 chemical workers exposed to benzene in various manufacturing processes after 1935.

Methods: The cohort has accumulated over 80 000 person-years of observation; about 70% of the workers were followed for more than 30 years since first exposure.

Results: Mortality from non-malignant diseases of the blood was increased (SMR 2.17, 95% CI 0.87 to 4.48), and correlated with duration of benzene exposure, although risk had decreased from the previous investigation of this cohort. The risk for leukaemia was slightly above background (SMR 1.14, obs 12, 95% CI 0.59 to 1.99) but has also decreased since the earlier study of this cohort. SMRs for acute non-lymphocytic leukaemia (ANLL), chronic lymphatic leukaemia, and non-Hodgkin's lymphoma were 1.11, 0.42, and 1.06 respectively. There was evidence of a weak trend of increasing SMRs for leukaemia and possibly ANLL with increasing low-level cumulative exposure but not with other measures.

Conclusion: Leukaemia and ANLL results were consistent with the mildly increased risk estimates from lower exposure subgroups of the Pliofilm cohort.

     

Practice area and work demands in nurses' aides: a cross-sectional study

Background

This paper examines the association between use of protective devices, frequency of acute health problems and health-protection information received by participants engaged in the Prestige oil spill clean-up in Asturias and Cantabria, Spain.

Methods

We studied 133 seamen, 135 bird cleaners, 266 volunteers and 265 paid workers selected by random sampling, stratified by type of worker and number of working days. Information was collected by telephone interview conducted in June 2003. The association of interest was summarized, using odds ratios (OR) obtained from logistic regression.

Results

Health-protection briefing was associated with use of protective devices and clothing. Uninformed subjects registered a significant excess risk of itchy eyes (OR:2.89; 95%CI:1.21–6.90), nausea/vomiting/dizziness (OR:2.25; 95%CI:1.17–4.32) and throat and respiratory problems (OR:2.30; 95%CI:1.15–4.61). There was a noteworthy significant excess risk of headaches (OR:3.86: 95%CI:1.74–8.54) and respiratory problems (OR:2.43; 95%CI:1.02–5.79) among uninformed paid workers. Seamen, the group most exposed to the fuel-oil, were the worst informed and registered the highest frequency of toxicological problems.

Conclusion

Proper health-protection briefing was associated with greater use of protective devices and lower frequency of health problems. Among seamen, however, the results indicate poorer dissemination of information and the need of specific guidelines for removing fuel-oil at sea.