The epidemiology of microbial keratitis has been investigated in several studies by analysis of organisms cultured from corneal scrapes. However, a comparison of the frequency of different organisms causing keratitis in different parts of the world is lacking. The authors present a review incorporating an analysis of data from studies worldwide. The data provide a comparison of the frequency of culture-positive organisms found in different parts of the world. Associations between a country's gross national income and types of causative organism are explored. The highest proportion of bacterial corneal ulcers was reported in studies from North America, Australia, The Netherlands and Singapore. The highest proportion of staphylococcal ulcers was found in a study from Paraguay, while the highest proportion of pseudomonas ulcers was reported in a study from Bangkok. The highest proportions of fungal infections were found in studies from India and Nepal. The Spearman correlation coefficient demonstrated statistically significant correlations between gross national income and percentages of bacterial (0.85 (95% CI 0.68 to 0.91, p<0.0001)), fungal (-0.81 (95% CI -0.90 to -0.66, p<0.0001)) and streptococcal (-0.43 (95% CI -0.66 to -0.12, p=0.009)) isolates.

The evidence for human carcinogenicity of formaldehyde remains unconvincing. Although a small effect on sino-nasal or nasopharyngeal cancer cannot be ruled out, a possible increase in the risk of lung cancer is a greater concern.

A job-exposure matrix has been applied in a case-control study of lung and bladder cancer on the basis of occupational information abstracted from British death certificates. The expected association between lung cancer and jobs entailing exposure to asbestos was clearly demonstrated (relative risk, 1.5; 95% confidence interval, 1.2-1.9). The effects of three other known industrial carcinogens were not apparent, and reasons for this were discussed. Also included in the matrix were five substances whose carcinogenicity in humans has not been established. Formaldehyde, diesel fumes, and cutting oils were all associated with carcinoma of the bronchus, but the absence of a risk in "high-exposure" occupations was against a causal relationship. Bladder cancer was more common in jobs involving high exposure to printing inks (relative risk, 5.0; 95% confidence interval, 1.0-25.8) and cutting oils (relative risk, 1.5; 95% confidence interval, 0.8-2.8). Use of the job-exposure matrix added considerably to the conventional analysis of cancer risk in individual occupational categories.

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The International Agency for Research on Cancer controversially has classified formaldehyde as causing nasopharyngeal carcinoma and myeloid leukemia. To provide further information on this question, we extended follow-up of a cohort of 14,008 chemical workers at 6 factories in England and Wales, covering the period 1941-2012. Mortality was compared with national death rates for England and Wales, and associations with incident upper airway cancer and leukemia were explored in nested case-control analyses. We observed excess deaths from cancers of the esophagus (100 observed vs. 93.1 expected), stomach (182 vs. 141.4), rectum (107 vs. 86.8), liver (35 vs. 26.9), and lung (813 vs. 645.8), but none of these tumors exhibited a clear exposure-response relationship. Nested case-control analyses of 115 men with upper airway cancer (including 1 nasopharyngeal cancer), 92 men with leukemia, and 45 men with myeloid leukemia indicated no elevations of risk in the highest exposure category (high exposure for ≥1 year). When the 2 highest exposure categories were combined, the odds ratio for myeloid leukemia was 1.26 (95% confidence interval: 0.39, 4.08). Our results provide no support for an increased hazard of myeloid leukemia, nasopharyngeal carcinoma, or other upper airway tumors from formaldehyde exposure. These results indicate that any excess risk of these cancers, even from relatively high exposures, is at most small.

Summary A cohort study was conducted to investigate the mortality of individuals employed by biological research institutes in the UK. The inclusion criteria were met by 12703 individuals, of whom 95% were traced (11 502 alive, 395 deaths, 246 embarkations). All-cause mortality was significantly reduced in men (standardised) mortality ratio (SMR) 55 and women (SMR 52). Mortality was also significantly reduced for circulatory and respiratory diseases, and overall there was low mortality from malignant neoplasms. SMRs exceeded 100, but were not statistically significant, for infective and parasitic diseases. There were no statistically significant raised SMRs for any cancer site. Workers were categorised as ever worked in a laboratory (laboratory workers) and never worked in a laboratory (non-laboratory workers). The all-cause SMR was significantly reduced in both groups, as was mortality from circulatory and respiratory diseases. The SMR for malignant neoplams was also significantly reduced in laboratory workers. On the basis of follow-up to 31 December 1994, there is no evidence of any overall increased risk of mortality in biological research laboratory workers. However, the power of the analysis is limited by the young age of many cohort members and short duration of follow-up. Follow-up is continuing and the data will be reanalysed once more deaths have accumulated.

Farmers are exposed to a wide range of occupational hazards. They are at risk of many forms of injury, particularly from the machinery that they use and the animals that they handle; they work with pesticides and other toxic chemicals; they carry out frequent, heavy manual handling tasks; they are exposed to various allergens in the course of their work; and they Proportional mortality ratios (PMRs) were calculated for each cause of death, with fiveyear age, sex, and social class specific proportions in all occupations combined for the whole of England and Wales providing the standard. For analyses of male and female farmers, the standard comprised all deaths for which an occupation had been recorded on the certificate. For farmers' wives the standard was all deaths in married women whose husbands' occupations had been recorded. Confidence intervals (CIs) for PMRs were derived by the method described by Breslow

Objectives: To investigate the incidence, nature and determinants of non-fatal occupational injuries in British agriculture. Methods: As part of a postal survey, data on lifetime histories of work in agriculture and occupational accidents were obtained from men born between 1933 and 1977 and residing in three rural areas of England and Wales. Incidence rates for different categories of accident were compared with those derived from statutory reporting. Associations with risk factors were explored by Poisson regression, and summarised by incidence rate ratios (IRRs). Results: Of the 10 765 responders (response rate = 31%), 3238 (30%) reported at least one occupational accident at the ages of 14-64 years, leading to absence from work for >3 days, including 1492 accidents that could be linked to a specific job listed in the history of agricultural work. The reported incidence of injuries in agriculture was markedly higher than that derived from statutory reporting, particularly for self-employed farmers. During 1996-2003, the highest rates of agricultural accidents were from handling, lifting or carrying (4.9/1000 person-years), falls from a height (4.6/1000 person-years) and injury by animals (3.4/ 1000 person-years). After adjustment for calendar period and age, the risk of accidents was elevated in men who had only recently entered agricultural work (IRR 3.7, 95% CI 2.7 to 5.1 for men who had worked in agriculture for up to 1 year relative to those who had entered the industry .25 years earlier), and in those who carried out forestry (IRR 1.7, 95% CI 1.5 to 1.9). Conclusion: Our findings confirm the substantial underascertainment of serious accidental injuries in agriculture through statutory reporting, particularly for the self-employed. The risk of accidents is highest in new recruits to the industry and in those undertaking forestry, and these groups should be a target for further preventive action.