Sample Accident Report

Figure 4.4 (a) Fatal and major injuries per thousand employees, (b) Accidents reported per thousand employees among CIA members (voluntary sample). 

Descriptive statistics are techniques used to describe a population or sample. One cannot draw conclusions using descriptive statistics. For example, suppose a safety manager collects information from accident report forms about the age of workers that suffered a back injury. The average age for the sample was found to be 45 years old. The only conclusion the safety manager can make is that the average age of those persons from which the sample was selected is 45 years old. He or she cannot conclude that the average age for all people ever suffering from a back injury is 45 years... 

The variance of a distribution is a measure of how much the individual data points vary from the distribution mean, i.e., how spread out the data is. The variance is the average of the squared deviations from the mean and is calculated using the formula presented below. Using the data for the number of hazards identified in various locations above, the variance provides an indication as to how much the number of accidents reported differs from the average. (When the variance is calculated for a sample, as is the case in this example, the sum of the squared deviation scores is divided by N - 1, where N is the number of observations. When the variance is calculated for an entire population, the sum of the squared deviation scores is divided by N.)... 

The book includes helpful resources in the appendices, such as a nurse safety perception survey, an accident causal factor chart, sample ergonomics symptoms report, sample TB exposure control plan, and a model respirator plan for small organizations. Complete with review exercises in each chapter, this book is ideal for certification training in nursing programs and as a reference for developing nursing in-service safety sessions. 

FIG. 3.2. Sample mine training bulletin. This document shows trainers how to structure accident report narratives. Source U.S. Department of the Interior, Bureau of Mines (1993, p. 55). 

Trend analysis can be confused or invalidated by a sample that is too small. If the charting or analysis is limited only to major incidents, there will often be too few within a period to arrive at meaningful conclusions. For example, a facility with one thousand employees may experience only one or two serious incidents per year, and several years worth of data would be needed to make any meaningful statistical analysis. Minor incidents and near misses can be as useful in trend analysis and preventive prediction as major incidents. All process incidents should be reported, classified, and investigated as appropriate. The severity of an incident is frequently more a function of chance than actual fundamental system differences among accidents and near misses. 

GHB can be formed from GABA and is found naturally in human tissues. In non-GHB users, however, GHB is usually not detected in blood or urine samples. Also, since GHB appears to form in blood postmortem, a finding of GHB is not indicative of use unless there is evidence of oral intake. Because of its short half-life, GHB is not found in blood 8 hours after use or in urine after 24 hours. However, lack of GHB after these intervals is not indicative that GHB was not used in an alleged rape. There are many reports of GHB being involved in overdoses, motor vehicle accidents, and deaths. 

The discovery happened by accident. Lewis and Anders were frustrated by their failure to find the carrier of anomalous xenon in carbonaceous chondrites. They decided to try an extreme treatment to see if they could dissolve the carrier. They treated a sample of the colloidal fraction of an Allende residue with the harshest chemical oxidant known, hot perchloric acid. The black residue turned white, and to their surprise, when they measured it, the anomalous xenon was still there The residue consisted entirely of carbon, and when they performed electron diffraction measurements on it, they found that it consisted of tiny (nanometer sized) diamonds. After a detailed characterization that included chemical, structural, and isotopic studies, they reported the discovery of presolar diamond in early 1987 (Lewis et al., 1987). The 23-year search for the carrier of CCFXe (Xe-HL) was over, and the study of presolar grains had begun. 

Certain widely used solvents such as diethyl ether or methylene chloride are highly volatile. Excess pressure buildup may cause rapture of the separatory funnel. Many accidents have been reported. It is important to vent out the excess pressure, especially after the first time shaking the sample with the solvent. Before extraction, rinse the separatory funnel with a few milliliters of the solvent. A glass container that has even a slight crack should not be used for extraction. 

Crooks, R.N., Glover, K.M., Haynes, J. W., Osmond, R.G. Rogers, F.J.G. (1959) Alpha activity on air filter samples collected after the Windscale accident. AERE Report R-2952. HMSO, London. 

Endocrine Effects. No biochemical evidence of thyroid dysfunction, as evaluated by serum levels of T4, triiodothyronine, and TSH, were reported in a group of 18 workers examined 17 years after an industrial accident during the manufacture of 2,4,5-T (Jennings et al. 1988). The small sample size, the fact that no measure of exposure was provided, and the long period of time between exposure and examination preclude any conclusion regarding possible effects of 2,3,7,8-TCDD. Zober et al. (1994) found a significant increase in the incidence of thyroid disease (no further details provided) 35 years after the BASF accident. An increased incidence of diabetes and subclinical decreases in thyroid function were found in Vietnam veterans who participated in operation Ranch Hand (USAF 1991). 

Individuals exposed through industrial accidents or environmental contamination. Very extensive residential contamination by 2,3,7,8-TCDD occurred in Seveso, Italy, when a 2,4,5-TCP reactor exploded in 1976 (Mocarelli et al. 1991). The contaminated area was divided into three zones based on the concentration of 2,3,7,8-TCDD in the soil. Families in zone A, the most heavily contaminated area based on soil 2,3,7,8-TCDD levels, were evacuated within 20 days of the explosion and measures were taken to minimize exposure of residents in nearby zones. A recent analysis of 19 blood samples from residents of zone A, which were collected and stored shortly after the accident, showed serum lipid levels of 2,3,7,8-TCDD that ranged from 828 to 56,000 ppt. These serum lipid levels are among the highest ever reported for humans (Mocarelli et al. 1991). 

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