A matched case-control study of convenience store robbery risk factors.

Convenience store clerks have been shown to be at high risk for assault and homicide, mostly owing to robbery or robbery attempts. Although the literature consistently indicates that at least some environmental designs are effective deterrents of robbery, the significance of individual interventions and policies has differed across past studies. To address these issues, a matched case-control study of 400 convenience store robberies in three metropolitan areas of Virginia was conducted. Conditional logistic regression was implemented to evaluate the significance of various environmental designs and other factors possibly related to convenience store robbery. Findings indicate that numerous characteristics of the surrounding environment and population were significantly associated with convenience store robbery. Results also showed that, on a univariate level, most crime prevention factors were significantly associated with a lower risk for robbery. Using a forward selection process, a multivariate model, which included cash handling policy, bullet-resistant shielding, and numerous characteristics of the surrounding area and population, was identified. This study addressed numerous limitations of the previous literature by prospectively collecting extensive data on a large sample of diverse convenience stores and directly addressing the current theory on the robbers' selection of a target store through a matched case-control design.

Adherence to guidelines for antiretroviral therapy and for preventing opportunistic infections in HIV-infected adults and adolescents in Ryan White-funded facilities in the United States.

To determine adherence by health care providers to guidelines for antiretroviral therapy and for prevention of opportunistic infections (OIs) in adults with HIV infection in federally funded facilities in the United States, we reviewed records of HIV-infected adults (>13 years) in 11 Ryan White Title III facilities in four states for information on eight standard-of-care recommendations during November 1996 through September 1997. Eligibility required a visit to the facility within 6 months before record abstraction and a lowest CD4+ lymphocyte count <500 cells/microl. Reviews were completed for 148 patients in Maryland, 355 in New York, 370 in Georgia, and 538 in Illinois. Adherence to prevention measures by health care providers was >85% for HIV plasma RNA testing, prescription of antiretroviral therapy, Pneumocystis carinii pneumonia (PCP) prophylaxis, anti-Toxoplasma antibody testing, and obtaining Papanicolaou (Pap) smears but lower (69%-80%) for Mycobacterium avium complex (MAC) prophylaxis, tuberculin skin testing (TST), and pneumococcal vaccination. Adherence was similar by patient age, gender, racial/ethnic group, urban versus rural, and hospital versus clinic setting but was generally lower for injecting drug users (IDUs) than for patients with other HIV exposures (p < .05 by multivariate analysis for TST, anti-Toxoplasma antibody testing, Pap smear, and measurement of HIV plasma RNA). Adherence by health care providers to guidelines for preventing OIs in these federally funded facilities is generally high but could be improved for some prevention measures, for instance, MAC prophylaxis, TST, and pneumococcal vaccination, especially for IDUs.

Convenience store robberies in selected metropolitan areas. Risk factors for employee injury.

Circumstances of injury were abstracted from police reports for 1835 convenience store robberies that occurred during 1992 or 1993 in selected metropolitan areas of seven eastern states. Subset analyses were performed using the data (758 robberies) from four states with relatively complete risk factor information. The purpose of this study was to estimate the risk of injury in a robbery situation for various risk factors. The overall risk of employee robbery-related injury could not be estimated because the probability of robbery is unknown. Of the 1835 robberies, 59% of the total robberies occurred at nighttime (9 p.m. to 3 a.m.), 47% occurred in stores previously robbed in the study period, 63% involved the use of a firearm, and 12% were associated with an injury to at least one employee. In the subset analysis of 758 robberies in four states, the employee probability of injury in a robbery was lower with firearm use compared with no weapon or use of a blunt instrument, and the probability of severe injury (defined as death, or an injury necessitating a trip to a hospital) was lower with a firearm compared with the use of a blunt instrument. However, all five fatalities were firearm-related. Other factors that were associated with a lower probability of employee injury included robbery occurrence in stores that had been robbed multiple times, compared with stores robbed only once; having 1 to 999 dollars stolen, compared with having no money stolen; and the presence of a customer(s) in the store at the time of the robbery. The employee risk of injury was not significantly different between one- (0.106) and multiple-employee (0.111) stores. Similarly, the employee risk of severe injury was not significantly different between one- (0.029) and multiple-employee stores (0.022). We conclude that there are several potential risk factors for employee injury in convenience store robberies, some of which are amenable to interventions. Further research on these factors and their relationship to employee injury is indicated.

Employee injuries and convenience store robberies in selected metropolitan areas.

The number of robberies and robbery-related injuries to employees in convenience stores (C-stores) during 1992 or 1993 were estimated for selected metropolitan areas around Miami and Tampa, Florida; Atlanta, Georgia; Chicago, Illinois; Baltimore, Maryland; Boston, Massachusetts; Detroit, Michigan; Pittsburgh and Philadelphia, Pennsylvania; Charleston, Columbia, Greenville, and Spartanburg, South Carolina; and Arlington, Chesterfield, and Henrico counties, Virginia. Of the 1835 C-store robberies that occurred during 1992 or 1993 in all selected areas (excluding Atlanta and Chicago), there were 12 homicides of C-store employees; 219 nonfatal injuries of C-store employees; 1071 robberies in which there were no injuries but a weapon was used, displayed, or implied toward a C-store employee; and 132 robberies in which there was no injury and no weapon used, but an employee was struck, pushed, or shoved. Corresponding figures for the 238 robberies that occurred in Chicago during January to June 1993, and for which victim employment status was unknown (customer or employee) were three homicides, 53 nonfatal injuries, 120 attacks in which a weapon was used but there was no injury, and 57 attacks in which a person was struck, pushed, or shoved but there was no injury. The proportion of robberies that resulted in a homicide or injury to an employee varied among selected areas from .03 to .25. The proportion of homicides and injuries to an employee was. 14 or higher for target areas in Baltimore (.24), Detroit (.25), and Virginia (.14); the proportion to an employee or customer was .24 in Chicago. The conclusions from these data are that the risk of employee injury in C-store robberies was high in selected metropolitan areas. This underscores the need for effective robbery prevention programs to reduce injury. In addition, further research is needed to determine the effectiveness of prevention programs in the C-store industry and the application of these programs to other retail industries.

Reevaluation of the effectiveness of environmental designs to reduce robbery risk in Florida convenience stores.

Prevention of intentional injuries to convenience store workers has focused on prevention of robbery. Data from a cross-sectional study of the effectiveness of environmental designs to deter robbery in Florida convenience stores were reanalyzed in order to determine the effect of confounding from local crime risk factors and other environmental designs on robbery rate. Results of this reanalysis were applied to a review of the literature. Of 14 store design factors and 5 local crime risk factors considered, concealed access/escape routes, cash register located at the back or the side of the store, high county crime rate, and high county population size were significantly associated with increased robbery rate. Poor cash handling policy was significantly related to a decreased robbery rate. Results also indicated that local crime factors and some environmental designs confound the relationship between other environmental designs and robbery rate. Conclusions from this reanalysis indicated that studies of the effectiveness of environmental designs to deter robbery must adjust for confounding. Although environmental design tends to be an effective robbery deterrent strategy, results from studies have been inconsistent as to the effectiveness of specific design factors. This inconsistency is partially explained by lack of adjustment for confounding from local crime risk factors and multiple environmental design factors. Areas for further research are discussed.

Silicosis and lung cancer among workers in North Carolina dusty trades.

In 1940-1983, 760 cases of silicosis were identified among male North Carolina (NC) workers in dusty trades. Vital status was ascertained through 1983 for 714 silicotics, and death certificates were obtained for 546 of the 550 decedents. The standardized mortality ratio (SMR) for lung cancer based on United States rates was 2.6 [95% confidence interval (95% CI) 1.8-3.6] for whites, 2.3 (95% CI 1.5-3.4) for whites unexposed to other known occupational carcinogens, and 2.4 (95% CI 1.5-3.6) for whites with no other exposure and diagnosed with silicosis while still employed in dusty trades. In addition, the age- and smoking-adjusted rate for silicotics was 3.9 times higher (95% CI 2.4-6.4) than that of nonsilicotic metal miners. This analysis effectively controlled for confounding by age, cigarette smoking, exposure to other occupational carcinogens, and detection bias. The results congrue with the hypothesis of an association between silicosis and lung cancer.

Reevaluation of silicosis and lung cancer in North Carolina dusty trades workers.

We previously reported on the lung cancer mortality through 1983 of 760 males who were diagnosed with silicosis during 1930-1983 by the State of North Carolina's medical examination program for dusty trades workers. The lung cancer SMR (95% confidence interval) was 2.6 (1.8-3.6) among 655 white members of this group. In this paper, we report the results of a reanalysis of mortality among a subgroup for whom chest radiographs were currently available for rereading. Technically acceptable radiographs were available for 306 white males and were independently reclassified for pneumoconiosis by 3 "B" readers using the 1980 ILO Classification. Lung cancer SMRs were 1.7 (0.8-3.1) for the entire group of 306 white males, 2.5 (1.1-4.9) for 143 subjects reclassified as simple silicosis, and 1.0 (0.1-3.5) for 96 subjects whose radiographs were reclassified as ILO category 0. There were no lung cancer deaths among 67 subjects whose radiographs were reclassified as progressive massive fibrosis. Corresponding lung cancer SMRs for subjects who had never been employed in a job with exposure to known occupational carcinogens were 1.2 (0.2-4.4) for those reclassified as category 0, and 2.4 (1.0-5.0) for those reclassified as having simple silicosis. The age-adjusted lung cancer rate ratio among subjects with simple silicosis compared to those with category 0 was 1.5 (0.4-5.8). Our findings from this reanalysis, which effectively controls for misclassification of silicosis due to errors in radiograph interpretation by North Carolina program readers, offer additional evidence consistent with the hypothesis of an association between silicosis and lung cancer in this study group.

Silicosis and lung cancer in North Carolina dusty trades workers.

Since 1940, 760 cases of silicosis have been diagnosed as part of the State of North Carolina's (NC) pneumoconiosis surveillance program for dusty trades workers. Vital status was ascertained through 1983 for 714 cases that had been diagnosed since 1940 and death certificates were obtained for 546 of the 550 deceased. Mortality from tuberculosis, cancer of the intestine and lung, pneumonia, bronchitis, emphysema, asthma, pneumoconiosis, and kidney disease was significantly increased in whites. Mortality from tuberculosis, ischemic heart disease, and pneumoconiosis was significantly increased in non-whites. The standardized mortality ratio (95% CI) for lung cancer based on U.S. rates was 2.6 (1.8-3.6) in whites, 2.3 (1.5-3.4) in those who had no exposure to other known occupational carcinogens, and 2.4 (1.5-3.6) in those who had no other exposure and who had been diagnosed for silicosis while employed in the NC dusty trades. Age-adjusted lung cancer rates in silicotics who had no exposure to other known occupational carcinogens were 1.5 (.8-2.9) times higher than that in a referent group of coal miners with coalworkers' pneumoconiosis (CWP) and 2.4 (1.5-3.9) times higher than that in a referent group of non-silicotic metal miners. Age- and smoking-adjusted rates in silicotics were 3.9 (2.4-6.4) times higher than that in metal miners. This analysis effectively controls for confounding by age, cigarette smoking, and exposure to other known occupational carcinogens, and it is unlikely that other correlates of silica exposure could explain the excess lung cancer mortality in the silicotics.

Respirable dust exposures in U.S. surface coal mines (1982-1986).

Exposure of miners to respirable coal mine dust and to respirable quartz silica at surface coal mines in the United States during 1982-1986 were evaluated by job category using data collected by coal mine operators and Mine Safety and Health Administration (MSHA) inspectors. Average coal mine dust concentrations were usually well below the MSHA Permissible Exposure Limit (PEL) for all job categories, but at least 10% of the samples obtained from some coal preparation plant job areas and most drilling job areas had concentrations that exceeded the 2.0 mg/m3 limit. In contrast, a very high proportion of samples from surface mine driller areas exceeded the quartz PEL. Of all samples collected for highwall drill operators and helpers, 78% and 77%, respectively, were greater than the 0.1 mg/m3 quartz exposure limit (average concentrations were .32 and .36 mg/m3, respectively). Although MSHA compliance data may not be entirely adequate for assessing chronic exposure to quartz, these data and the results of other NIOSH studies nonetheless indicate excessive exposure to silica in a group of surface coal miners.

Health status of anthracite surface coal miners.

In 1984-1985, medical examinations consisting of a chest radiograph, spirometry test, and questionnaire on work history, respiratory symptoms, and smoking history were administered to 1,061 white males who were employed at 31 coal cleaning plants and strip coal mines in the anthracite coal region of northeastern Pennsylvania. The prevalence of radiographic evidence of International Labour Office (ILO) category 1 or higher small opacities was 4.5% in 516 men who had never been employed in a dusty job other than in surface coal mining. Among these 516 workers, all 4 cases of ILO radiographic category 2 or 3 rounded opacities and 1 case of large opacities had been employed as a highwall drill operator or helper. The prevalence of category 1 or higher opacities increased with tenure as a highwall drill operator or helper (2.7% for 0 y, 6.5% for 1-9 yr, 25.0% for 10-19 y, and 55.6% for greater than or equal to 20 y drilling). Radiographic evidence of small rounded opacities, dyspnea, and decreases in FEV1.0, FVC, and peak flow were significantly related to tenure at drilling operations after adjusting for age, height, cigarette smoking status, and exposures in dusty jobs other than in surface coal mining. However, tenure in coal cleansing plants and other surface coal mine jobs were not related to significant health effects. The apparent excess prevalence of radiographic small rounded opacities in anthracite surface coal mine drillers suggests that quartz exposures have been increased. Average respirable quartz concentrations at surface coal mine drilling operations should be evaluated to determine whether exposures are within existing standards, and dust exposures should be controlled.

Dust exposures at U.S. surface coal mines in 1982-1983.

Exposures to British Mining Research Establishment corrected respirable dust and respirable quartz at U.S. surface coal mines during 1982-1983 were evaluated from coal mine operator and Mine Safety and Health Administration (MSHA) inspector samples. The average respirable quartz concentration from inspector samples ranged from .34-.49 mg/m3 for drilling jobs and .18 mg/m3 for bulldozer operators. For most other surface coal mine jobs, the average respirable quartz concentration was less than .1 mg/m3, and the average respirable dust concentration was less than 2 mg/m3. The results from the analysis of quartz exposures are consistent with epidemiological results for an increased silicosis risk among drillers. It is unclear, however, whether the MSHA samples provide a representative estimate of the average annual quartz concentration for drillers. Results suggest the need for a greater number of quartz samples to be taken on strip coal miners, particularly on drillers and bulldozer operators.

The morbidity and mortality of vermiculite miners and millers exposed to tremolite-actinolite: Part II. Mortality.

The vermiculite ore and concentrate of a mine and mill located near Libby, Montana was found to be contaminated with a fiber of the tremolite/acetinolite series. A study was conducted to estimate the exposure-response relationship for mortality for 575 men who had been hired prior to 1970 and employed at least 1 year at the Montana site. Individual cumulative fiber exposure (fiber-years) was calculated. Results indicated that mortality from nonmalignant respiratory disease (NMRD) and lung cancer was significantly increased compared to the U.S. white male population. For those workers more than 20 years since hire, the standard mortality rate (SMR) for lung cancer (ICDA 162-163) was 84.7, 225.1, 109.3, and 671.3 for less than 50, 50-99, 100-399, and more than 399 fiber-years respectively. Corresponding results for NMRD (ICDA 460-519) were 327.8, 283.5, 0, and 278.4. Based on a linear model for greater than 20 years since hire, the estimated percentage increase in lung cancer mortality risk was 0.6% for each fiber-year of exposure. At 5 fiber-years, the estimated percentage was 2.9% from an unrestricted (nonthreshold) linear model and 0.6% from a survival model.

The morbidity and mortality of vermiculite miners and millers exposed to tremolite-actinolite: Part I. Exposure estimates.

The vermiculite ore and concentrate of a mine and mill near Libby, Montana, was found to be contaminated with fibrous tremolite-actinolite. Of 599 fibers (length greater than 5 microns and width greater than 0.45 micron) counted in eight airborne membrane filter samples, 96% had an aspect ratio greater than 10 and 16% had an aspect ratio greater than 50. Additionally, 73% of the fibers were longer than 10 microns, 36% were longer than 20 microns, and 10% were longer than 40 microns. Estimates of exposure before 1964 in the dry mill were 168 fibers/cc for working areas, 182 fibers/cc for sweepers, 88 fibers/cc for skipping, and 13 fibers/cc for the quality control laboratory. In 1964-1971, exposure estimates for these areas were 33, 36, 17, and 3 fibers/cc, respectively. Estimates of exposures in the mine before 1971 ranged from 9-23 fibers/cc for drillers and were less than 2 fibers/cc for nondrilling jobs. All 8-hr TWA job exposure estimates decreased from 1972-1976, and from 1977-1982 were less than 1 fiber/cc.

The morbidity and mortality of vermiculite miners and millers exposed to tremolite-actinolite: Part III. Radiographic findings.

A study was conducted to estimate the exposure-response relationship for tremolite-actinolite fiber exposure and radiographic findings among 184 men employed at a Montana vermiculite mine and mill. Workers were included if they had been employed during 1975-1982 and had achieved at least 5 years tenure at the Montana site. Past fiber exposure was associated with an increased prevalence of parenchymal and pleural radiographic abnormalities. Smoking was not significantly related to the prevalence of small opacities. However, the number of workers who had never smoked was small, and this prevented measurement of the smoking effect. Under control for smoking and age, the prevalence of small opacities was significantly greater for vermiculite workers with greater than 100 fiber/cc-years exposure than for comparison groups (cement workers, blue collar workers, and coal miners) who had no known occupational fiber exposure. A logistic model predicted an increase of 1.3% in the odds ratio for small opacities at an additional exposure of 5 fiber-years.

Mortality from stomach cancer in United States cement plant and quarry workers, 1950-80.

In 1978 a study of the mortality of United States cement plant and quarry workers was initiated. The vital status of a cohort of 5292 men who had been employed for at least five years in a cement plant between 1950 and 1980 was traced to 1 January 1980. The mortality experience was evaluated for 4231 white men for whom complete work histories and demographic information were available. Deaths from stomach cancer were significantly increased during 1965-9 but not over the entire follow up period (1950-80). Additionally, stomach cancer mortality was not significantly associated with tenure under separate control for age at follow up, latency, nativity, or year of birth. Evidence from this and other epidemiological studies has not confirmed an association between the constituents of cement plant dust exposure and death from stomach cancer.

A re-evaluation of radiological evidence from a study of U.S. strip coal miners.

In 1972, the U.S. Public Health Service examined 1438 workers employed at seven bituminous and one anthracite U.S. strip coal mines. One conclusion from the study was that workers without previous dust exposures were not at risk of category 2 or higher pneumoconiosis from their strip coal mining environment. Because of recent concerns for silicosis among strip coal miners, the radiographs were reinterpreted and the data re-evaluated. In addition, data from respirable coal mine dust samples collected from 1972 to 1979 in all surface coal mines were analyzed. The results showed that category 2 or higher pneumoconiosis was prevalent among strip coal miners with experience in an underground coal mine. Among those without underground coal mine experience, category 2 or higher was prevalent among anthracite strip miners, but not among bituminous strip miners. Average respirable coal mine dust exposures in the anthracite mine were less than 1 mg/m3 prior to 1975 and, coupled with the radiographic findings, suggest further study of the efficacy of the 2 mg/m3 U.S. Federal surface coal mine dust standard in anthracite coal mines.

Respiratory status of surface coal miners in the United States.

The United States Public Health Service examined 1,438 surface coal miners to determine the prevalence of coal worker's pneumoconiosis (CWP), chronic bronchitis, and ventilatory impairment among them. Four percent (fifty-nine individuals) showed some roentgenographic evidence of pneumoconiosis, but only seven miners had films interpreted as CWP of category 2 or greater (according to the UICC/Cincinnati classification system). Moreover, most of the affected miners had worked in underground coal mines for prolonged periods. Significant decrements in pulmonary function to increasing exposure to surface mine dust were demonstrated only in the forced vital capacity of smokers. Increased prevalence of chronic bronchitis with increasing exposure was found in all smoking categories. However, significant airway obstruction was an uncommon finding (6.6%) in nonsmoking miners. Employment in surface mining was not likely to cause either the development of CWP or clinically significant respiratory impairment.

Significance of irregular small opacities in radiographs of coalminers in the USA.

The purpose of this study was to determine the factors that are associated with the occurrence of small irregular opacities in the chest radiographs of coalminers, and whether the lung function of miners with irregular opacities differed from that of miners with small rounded opacities, a mixture of small rounded and irregular opacities, or an absence of opacities. A subsample of 6166 coalminers was selected from 9076 miners who had been examined by the US Public Health Service as part of the National Study of Coalworkers' Pneumoconiosis. The subsample consisted of 4479 smokers and 1687 non-smokers. The chest radiograph of each miner was classified according to the UICC/Cincinnati Classification.