Skin cancer in people with multiple sclerosis: a record linkage study.

OBJECTIVE: The prevalence of multiple sclerosis (MS) varies with latitude: it increases with distance from the equator in both hemispheres. To seek evidence on whether solar radiation is a protective factor for MS, this study investigated whether skin cancer, as an indicator of solar radiation, is less common in people with MS than in others. DESIGN: Analysis of a database of linked hospital records and death certificates. SETTING: The Oxford Region of the National Health Service, England. SUBJECTS: A cohort comprising all people in the database with MS, and comparison cohorts of people with other diseases. RESULTS: Skin cancer was significantly less common in people with MS than in the main comparison cohort (rate ratio 0.49; 95% confidence interval 0.24 to 0.91). There was no general deficit of cancer in the MS cohort, and no deficit of skin cancer in cohorts of people with other autoimmune or neurological diseases. CONCLUSION: The findings support the hypothesis that solar radiation may have a protective influence on the development of MS.

Health problems in Iraq.

PIP: Iraq is faced with large scale public health problems that have been caused by the destruction to their infrastructure during the Gulf war. Humanitarian aid is needed in order to avoid a large scale human disaster. In 1988 73% of Iraq's population lived in urban areas. The loss of electrical generating capacity has affected hospitals, water purification and sewage treatment. Iraq had made great strides int he health of their people with an infant mortality rate of 42/1000 in 1990 and 52./1000 for children under 5. The international study team's survey of over 9000 households revealed surprising evidence of widespread chronic malnutrition. Based on accepted mortality as a baseline, data suggests that mortality among Iraqi infants and children under 5 doubled in 1991. The current food ration provides only half of the energy requirement and with rapidly accelerating inflation, the cost of food while only make the situation worse. The UN Disaster Relief Office has received $1.059 billion from donor countries; but, only half of the requested $14 million has been funded through Unicef. This money is needed to meet basic requirements for water, sanitation, antibiotics, and vaccines. The UN Security Council approved resolutions 706 and 712 which would have allowed Iraq to sell $1.6 billion for foodstuffs, medicines, and materials and supplies necessary to civilian needs subject to monitoring and supervision to ensure equitable distribution. The Iraqi government has not met the requirements of 706 and 712 because of the monitoring conditions, so no money has been issued. More money is needed if humanitarian organizations are to do their work. Only $29 million of the $145 million needed for the 1st half of this year has been pledged.^ieng

Occupation and five cancers: a case-control study using death certificates.

A case-control approach has been used to examine mortality from five cancers--oesophagus, pancreas, cutaneous melanoma, kidney, and brain--among young and middle aged men resident in three English counties. The areas studied were chosen because they include major centres of chemical manufacture. By combining data from 20 years it was possible to look at local industries with greater statistical power than is possible using routine national statistics. Each case was matched with up to four controls of similar age who died in the same year from other causes. The occupations and industries recorded on death certificates were coded to standard classifications and risk estimates derived for each job category. Where positive associations were found the records of the cases concerned were examined in greater detail to see whether the risk was limited to specific combinations of occupation and industry. The most interesting findings to emerge were risks of brain cancer associated with the production of meat and fish products (relative risk (RR) = 9.7, 95% confidence interval (CI) 2.6-36.8) and with mineral oil refining (RR = 2.9, CI 1.2-7.0), and a cluster of four deaths from melanoma among refinery workers (RR = 16.0, CI CI 1.8-143.2). A job-exposure matrix was applied to the data but gave no strong indications of further disease associations. Local analyses of occupational mortality such as this can usefully supplement national statistics.

Mortality of workers exposed to styrene in the manufacture of glass-reinforced plastics.

Epidemiologic studies have suggested an increased risk of leukemia and lymphoma among workers exposed to styrene. In a further exploration of this possible hazard, an analysis was conducted of the mortality among 7,949 men and women employed during 1947-1984 in eight British companies manufacturing glass-reinforced plastics. The subjects were identified from company files and traced to the end of 1984 through National Health Service and National Insurance records. The overall mortality in the cohort was less than in the national population (693 deaths observed, 830.1 expected) as was mortality from cancer (181 deaths observed, 223.7 expected). In particular, there was a deficit of deaths from lymphoid and hemopoietic cancer (6 observed, 14.9 expected). The small excess of lung cancer (89 deaths observed, 80.1 expected) was not statistically significant and can probably be attributed to chance. Among 3,494 hand laminators (the job with the highest exposure to styrene) there was one death from lymphoma and none from leukemia. The findings do not exclude the possibility that styrene is a human carcinogen, but give no support to the hypothesis that it causes leukemia and lymphoma.

Mortality of workers exposed to 2 methyl-4 chlorophenoxyacetic acid.

The authors examined the mortality and cancer incidence of employees at a company which has manufactured, formulated, and sprayed 2 methyl-4 chlorophenoxyacetic acid (MCPA) and other phenoxy acid herbicides. Ninety-eight percent of the 5,784 men employed by the company during 1947-1975 was traced to the end of 1983. The overall mortality of the cohort was less than that of the national population, as was mortality from cancer. When allowance was made for rural residence, the deficit of cancer deaths became a slight excess, but not statistically significantly so. Among workers whose jobs entailed potential exposure to MCPA, there was one death from soft tissue sarcoma (0.6 expected). No further cases of soft tissue sarcoma were registered among living members of the cohort. Three potentially exposed workers died from nasal carcinoma, but this tumor has not previously been associated with phenoxy herbicides and the cluster of cases may have occurred by chance. The findings do not exclude the possibility that MCPA is a human carcinogen, but they suggest that any risk of soft tissue sarcoma is less than that indicated by earlier studies of 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) and 2,4,5-trichlorophenol and is small in absolute terms.

A survey of cancer and occupation in young and middle aged men. II. Non-respiratory cancers.

In a search for clues to previously unrecognised industrial carcinogens the occupational and smoking histories of young and middle aged men with different types of cancer have been compared. The study population comprised men aged 18-54 and resident in the counties of Cleveland, Humberside, and Cheshire (including the Wirral). Within this population 2942 patients in whom cancers were first diagnosed during the period 1975-80 were identified retrospectively from hospital and cancer registration records. Lifetime occupational and smoking histories were then sought from these subjects (or if they had died by proxy from their next of kin), using a postal questionnaire. The overall response rate was 52.1%. Analysis of limited occupational data obtained from the hospital notes of 89% of the patients suggests that no serious bias arose from the incomplete response to the questionnaire. The present paper describes the findings for non-respiratory cancers. Some tumours did not occur with sufficient frequency to warrant formal statistical analysis. Nevertheless, examination of the histories of patients with these cancers showed several interesting occupational clusters. In particular, five out of 29 patients with acute myeloid leukaemia had worked in electrical trades. The more common cancers were studied by statistical techniques. A large number of possible occupational associations were examined, and some will probably have achieved conventional levels of statistical significance by chance. The results should therefore be interpreted with caution, taking into account evidence from other studies and the biological plausibility of suggested hazards. Among the more interesting findings were an excess of bladder cancer in lorry drivers (RR=1.6, CI 1.0-2.4) and in men employed in the manufacture of vegetable and animal oils and fats (RR = 4.8, CI 1.8-12.9).

A survey of cancer and occupation in young and middle aged men. I. Cancers of the respiratory tract.

In a search for clues to previously industrial carcinogens the occupational and smoking histories of young and middle aged men with different types of cancer were compared. The study population comprised men aged 18-54 and resident in the counties of Cleveland, Humberside, and Cheshire (including the Wirral). From hospital and cancer registration records 2942 members of the study population in whom cancers were diagnosed during the period 1975-80 were identified retrospectively. The occupational and smoking histories of these patients were sought by a postal questionnaire addressed either to the patients themselves or, if they had died, to their next of kin. The overall response rate to the questionnaire was 52.1%. Additionally, limited occupational information was obtained for 89% of cases from their hospital notes. Analysis of these data suggests that no serious bias arose as a consequence of the incomplete response to the questionnaire. This paper concentrates on the results for cancers of the respiratory tract and mesothelioma. Mesothelioma was found to cluster in laggers, electricians, and shipyard workers, and nasal carcinoma in woodworkers. Carcinomas of the larynx and of the bronchus were examined by formal statistical techniques, each being compared with a control group made up of all other cancers combined. Several interesting occupational and industrial associations were shown, in particular, an excess of bronchial carcinoma in the leather industry (RR = 2.6, CI 1.2-6.0), in building labourers (RR = 1.7, CI 1.0-2.9) and other construction workers (RR = 1.8, CI 1.0-3.0), in bakers and pastry cooks (RR = 3.6, CI 1.3-10.4). and in cooks (RR = 2.5, CI 1.2-5.1). In addition, a small cluster of lung tumours was observed in men who had worked as dental mechanics.

AIDS: a challenge for the public health.

KIE: While the number of cases of acquired immunodeficiency syndrome (AIDS) has been increasing worldwide, the incidence in the United Kingdom (UK) is substantially lower than in the United States (US) and several other European countries. In the UK and US, the infection is confined largely to homosexual and bisexual men, persons who abuse drugs by injection, hemophiliacs, and sexual partners of members of these groups, including heterosexual men and women. Public education must focus on methods of transmission and control of the disease. The efficacy of testing for antibodies to the HTLV-III infection is questionable because there is no cure at present. Issues of confidentiality and denial of insurance or other support to persons who test positive must be considered.^ieng

PIP: This discussion of acquired immune deficiency syndrome (AIDS) covers the incidence of AIDS in Europe and the US, the means of spread, the pattern of incidence of aids within the population, prevalence of specific antibodies, heterosexual transmission, AIDS and HTLV-III infection in Central Africa, control of spread of the infection (public education, counseling, treating for antibodies to HTLV-III, control of nonsexual transmismission, and surveillanc); and confidentiality and other social issues. To judge by reported cases, the incidence of AIDS in the UK is at present substantially lower than in the US and in several other European countries. Up until September 30, 1985, the UK ranked 9th among 21 reporting European countries. Cumulative incidence rates almost 3 times the UK rate of 4.0 cases/million population have been reported Belgium (11.9), Denmark (11.2), and Switzerland (11.8). At a comparable date the cumulative incidence in the US was about 55/million. In the K as in the US, the infection is at present largely confined to homosexual and bisexual men, persons who abuse drugs by injection, Hemophiliacs, and sexual partners of these groups. Yet, since transmission can occur as a result of vaginal intercourse, public health policy must take into account the fact that heterosexual men and women in general also may possibly be risk. In view of the long latent period, the pattern of occurrence of positive antibody tests is a better guide to the future course of the epidemic than the number of cases of AIDS. The British serological data show that HTLV-III infection has increased in prevalence among homosexuals both in London and elsewhere. The average figure for 1984-85 in male homosexual attenders at genitourinary medicine was 21%. In drug abusers the comparable figure is lower (10%), but the recent report of prevalence rates in excess of 50% in Edinburgh drug addicts is an ominous development. The prevalence of antibody in hemophiliacs (31%) has not increased since 1984. In the absence of a vaccine or effective antiviral agents, public education to help people avoid risky sexual behavior and drug abuse is the mainstay of a policy for controlling the spread of infection. Such programs must meet the different needs of the general population, of the risk groups, and of adolescents. They also must include facts about how HTLV-III is and is not transmitted, practical advice on its avoidance, and advice to infected persons to help them avoid infecting others. If the use of serotesting is to be promoted for the control of infection, there willneed to be prior agreement about its efficacy.^ieng

Mortality study of workers in the man-made mineral fiber production industry in the United Kingdom.

The workforces of two factories in the United Kingdom have been followed up to the end of 1984 as part of the collaborative European study of the health of workers in the man-made mineral fiber industry. In the cohort from an English glass-wool plant there was no suggestion of any excess mortality compared to national or local rates, except for lung cancer among men in comparison to the national level. However, the data indicate that the workers were largely local persons by place of birth, occupation, and death, and they therefore suggest that the national comparison was inappropriate. Lung cancer mortality showed little relationship to length of employment, duration of time since first exposure, occupational classification, or level of exposure. In the cohort from a continuous-filament plant in Northern Ireland no excess mortality from cancer was found. There were, however, raised death rates from violent causes and cardiovascular disease, but these rates were not exceptional for the area of the country in which the factory was located. No deaths from mesothelioma were reported in either cohort.

A job-exposure matrix for use in population based studies in England and Wales.

The job-exposure matrix described has been developed for use in population based studies of occupational morbidity and mortality in England and Wales. The job axis of the matrix is based on the Registrar General's 1966 classification of occupations and 1968 classification of industries, and comprises 669 job categories. The exposure axis is made up of 49 chemical, physical, and biological agents, most of which are known or suspected causes of occupational disease. In the body of the matrix associations between jobs and exposures are graded to four levels. The matrix has been applied to data from a case-control study of lung cancer in which occupational histories were elicited by means of a postal questionnaire. Estimates of exposure to five known or suspected carcinogens (asbestos, chromates, cutting oils, formaldehyde, and inhaled polycyclic aromatic hydrocarbons were compared with those obtained by detailed review of individual occupational histories. When the matrix was used exposures were attributed to jobs more frequently than on the basis of individual histories. Lung cancer was significantly more common among subjects classed by the matrix as having potential exposure to chromates, but neither method of assigning exposures produced statistically significant associations with asbestos or polycyclic aromatic hydrocarbons. Possible explanations for the failure to show a clear effect of these known carcinogens are discussed. The greater accuracy of exposures inferred directly from individual histories was reflected in steeper dose response curves for asbestos, chromates, and polycyclic aromatic hydrocarbons. The improvement over results obtained with the matrix, however, was not great. For occupational data of the type examined in this study, direct exposure estimates offer little advantage over those provided at lower cost by a matrix.

The mortality of boot and shoe makers, with special reference to cancer.

The study describes the mortality of 5 017 men known to have been employed in the boot and shoe manufacturing industry in three towns in Great Britain in 1939. At the end of 1982, 97.5% of the men were traced, and 3 434 (68.4%) were known to be dead. Expected numbers were calculated according to the person-years method and were adjusted according to the standardized mortality ratios of the counties in which the towns were situated. The mortality experience of the men for all causes, all cancers combined, and all other causes was favorable. The anticipated excess of deaths from nasal cancer (10 observed, 1.87 expected) was found, and the excess was significant for workers in the finishing room. Deficits were found for other types of respiratory cancer. An excess mortality from leukemia was found for workers in one town (7 observed, 3.0 expected), and the excess was significant for workers in the lasting and making room, where glues and solvents, including benzene, were known to have been used. An excess mortality from rectal cancer was found for workers in two towns (61 observed, 47.6 expected), and it was significant for workers in the lasting and making rooms (25 observed, 12.4 expected). Some supporting evidence for a risk of rectal cancer in this industry was found in the literature.

Mortality of tanners.

The mortality of 833 male tannery workers known to have been employed in the industry in 1939 and who were followed up to the end of 1982 was studied. A total of 573 men had been employed in making leather tanned by vegetable extracts for soles and heels, and 260 men had used chrome tanning to make leather for the upper parts of shoes. No significant excesses of deaths were found for any of the common sites of cancer in either group of workers. One death from nasal cancer (0.21 expected) was reported among the men who worked with sole and heel leather.