Designer incident investigation studies

For how many incidents have the decisions affecting the sociotechni-cal workplace and work methods resulted in situations that are conducive to operator errors In Chapter 14, Incident Investigation Studies of Quality, it was said that in a substantial number of the investigation reports collected by this author, entries suggested that further inquiry should have been made into the design of the workplace or work methods. In many cases, the investigation reports pertained to incidents that occurred in error-provocative situations. Yet, often in those instances, only unsafe acts of employees would be recorded as the incident causal factors. 

Methyl bromide was tested by oral administration in rats and by inhalation in mice and rats. In one 90-day study by oral administration in rats, methyl bromide was reported to produce squamous-cell carcinomas of the forestomach. In a second, 25-week study designed to investigate further the findings of the previous study, early hyperplastic lesions of the forestomach developed after 25 weeks of continuous treatment by gavage. In two inhalation studies in mice, no significant increase in the incidence of tumours was observ ed. In one inhalation study in rats, an increase in the incidence of adenomas of the pituitary gland was observed in high-dose male rats. In another study in rats, no increase in tumour incidence was observed. 

European Prospective Investigation into Cancer and Nutrition (EPIC) Large study (over 500,000 participants) designed to investigate relationship between diet, nutritional status, lifestyle, and environmental factors and incidence of cancer and other chronic diseases. Blood samples are banked for future analyses (IARC 2005). 

If evidence of testicular atrophy was observed, we would be interested in designing a clinical study which would assess reproductive function in the exposed workers. If a two year ingestion study in rats reported a statistically significant incidence of neurotoxicity, we would want to investigate whether neurotoxic effects also were produced in an exposed worker population. 

Why a study of the quality of incident investigation There are three major elements in practice of safety preoperational (in the design process) in the operation mode (integrated within a process of continuous improvement) and post-incident (after a hazards-related incident has occurred). 

Although it is suggested that, in the study proposed, the reality of the design and engineering, operational systems, and cultural causal factors be identified and analyzed, safety professionals should not be surprised if the incident investigation reports are inadequate for in-depth causal factor determination. Mention was made previously of my studies of over 1200 incident investigation reports and that I found, in many instances, that causal factor determination was dismal. 

The hypothesis that dairy foods contain a cholesterol-lowering milk factor evolved from the observation that Maasai tribesmen of East Africa have low serum concentrations of cholesterol and a low incidence of cardiovascular disease in spite of their consumption of 4 to 5 liters/day of fermented whole milk (Mann and Spoerry 1974). Subsequently, sufficient amounts of yogurt, as well as unfermented milk (whole, lowfat, skim), were reported to exhibit a hypocholesterolemic effect both in humans and in laboratory animals in several studies (Mann 1977 Howard and Marks 1977, 1979 Nair and Mann 1977 Kritchevsky et al 1979 Richardson 1978 Hussi etal. 1981). However, not all investigators have observed a hypocholesterolemic effect of milk. This inconsistency may be explained in part by differences in the experimental design and in the specific type of dairy food used by investigators. 

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