Cost/benefit justifications are now required for new environmental regulations. The benefit is related to the difference between the currently existing health risk rate and the rate corresponding to the proposed permissible exposure limit. The adoption of many permissible exposure limits has been delayed by the lack of supporting human data and the use of animal data instead. This has resulted in difficulties and controversies not likely to be resolved soon. Meanwhile, a review of currently existing occupational risk rates can provide a perspective for best use of available funds. Tables and text are presented summarizing published occupational risk data for 1996. Transportation incidents cause 42 percent of occupational fatalities. Proper selection and training of workers and proper work rules should be costeffective, also especially in other listed dangerous industries. Annual risk rates per hundred workers for occupational non-fatal injuries and illness were surprisingly high: for manufacturing 10.6, and for the entire private sector, 7.4. Seven worst industries ranged from 25.8 to 30.3. The benefit from controlling such high rates is almost the same whether the final rate is 10-3 or 10-6. Thus, specifying a good low-cost procedure that reduces most of the initial risk can provide the lowest cost/benefit ratio, eligible for priority use of available funds.

Occupational risk of exposure to organic solvents concerned many shoe manufacturing workers. The most common organic solvents found in workplace environments were n-hexane and others hexane isomers. The aim of this study was to evaluate the exposure of shoe manufacturing workers to n-hexane, with 2,5 hexanedione in urine (2,5HD) as a biomarker and to investigate effect in 2,5 HD excretion of the co-exposure to other organic solvents. Post-shift urine samples from workers who performed gluing tasks (n = 45) in five shoe manufacturers were collected, as well as urine samples from a similar number of unexposed controls (n = 51) in the same factories. 2,5 HD was measured by capillary gas chromatography. Air monitoring of organic solvents in the workplaces was performed and the compounds were analyzed by gas chromatography. Significant more 2,5 HD was found in the urine of personnel who performed gluing tasks than in the unexposed workers. A significant correlation was observed between n-hexane exposure and urinary 2,5 HD, with a high correlation coefficient. Multiple regression analysis indicated that n-hexane exposure and co-exposure to others solvents were significant predictors of the concentration of 2,5 HD. Co-exposure led to higher urinary 2,5 HD concentrations. The significant effect of co-exposure reinforces the interest of biological monitoring for n-hexane exposure evaluation. In case of multiple exposures, biological monitoring can be a better predictive measurement for early detection of n-hexane neurotoxic lesions than air monitoring data.

Cost/benefit justifications are now required for new environmental regulations. The benefit is related to the difference between the currently existing health risk rate and the rate corresponding to the proposed permissible exposure limit. The adoption of many permissible exposure limits has been delayed by the lack of supporting human data and the use of animal data instead. This has resulted in difficulties and controversies not likely to be resolved soon. Meanwhile, a review of currently existing occupational risk rates can provide a perspective for best use of available funds. Tables and text are presented summarizing published occupational risk data for 1996. Transportation incidents cause 42 percent of occupational fatalities. Proper selection and training of workers and proper work rules should be cost-effective, also especially in other listed dangerous industries. Annual risk rates per hundred workers for occupational nonfatal injuries and illness were surprisingly high: for manufacturing 10.6, and for the entire private sector, 7.4. Seven worst industries ranged from 25.8 to 30.3. The benefit from controlling such high rates is almost the same whether the final rate is 10(-3) or 10(-6). Thus, specifying a good low-cost procedure that reduces most of the initial risk can provide the lowest cost/benefit ratio, eligible for priority use of available funds.

"North American Industry Classification System - A System for the Future." Applied Occupational and Environmental Hygiene, 16(6), p. 652

Acute cross-shift respiratory changes were evaluated for workers at 25 farms in northeastern Colorado during the summer of 1994 wheat harvest. Information on workers' respiratory health, past occupational exposures, and smoking status was obtained. Each worker was asked to rank eight acute symptoms before he or she began harvest work for the day. Spirometry was also performed before work began. Each participant wore a high-flow personal air sampling pump for the full shift. At the end of the workshift, spirometry and ranking of the eight acute symptoms were conducted again. Total dust exposure was determined gravimetrically. Total endotoxin was measured by the Limulus amoebocyte lysate (LAL) assay. The 98 harvest workers included in the study ranged in age from 18 to 80. Ten percent of the workers had moderate airway obstruction, as indicated by the pre-shift spirometry test results. Fifty percent of the workers were current or ex-smokers. Despite an unusually poor harvest, total dust exposures ranged from 0.09 to 15.33 mg/m3 (geometric mean 0.83 mg/m3), with 8 percent of workers exposed above the American Conference of Government Industrial Hygienists (ACGIH) threshold limit value (TLV) of 4 mg/m3. Total endotoxin exposures ranged from 4.4 to 744.4 EU/m3 (geometric mean 54.2 EU/m3), with 33 percent of workers exposed above 90 EU/m3, the level suggested as a threshold for acute mucous membrane irritation and pulmonary change among cotton workers. Sixty percent of workers experienced a cross-shift change in at least one respiratory symptom. The respiratory index (sum of cross-shift changes in the eight acute respiratory symptoms) was significantly correlated with both total dust and endotoxin exposure. Cross-shift changes in the spirometric variables were associated with smoking status, age, presence of airway obstruction, and history of chronic respiratory symptoms, but not with dust or endotoxin exposure. Peak expiratory flow rate was found to decrease over the workshift in a manner similar to that experienced by cotton workers.

Sick Building Syndrome remains a prevalent problem with patient complaints similar to typical allergy symptoms. Unlike household allergens typically found in domestic reservoirs, the allergen from a common fungus like Aspergillus fumigatus (i.e., Asp f 1) is conceivably widespread in the work environment. This project surveyed airborne levels of the Asp f 1 allergen in office and non-industrial occupational environments, as well as the dust reservoirs of A. fumigatus believed to be responsible for those levels. Airborne and bulk dust samples were collected, extracted, and assayed for Asp f 1. Concurrently, bulk dusts collected from the same locations were selectively cultured for A. fumigatus, and mesophilic fungi and bacteria. Samples were collected during both wet and dry climatological conditions from paired wet and dry building locations to examine the possibility of Asp f 1 increases due to fungal growth blooms. Very low levels of Asp f 1 were detected but only in the airborne samples (2/120 positive samples, with 3.6 ng/m3 and 1.8 ng/m3; LOD < 1.2 ng/m3). No dust samples showed even detectable traces of the allergen (LOD = 5 ng/g dust). Although A. fumigatus counts from dusts fluctuated significantly with exterior moisture events, analysis of wet versus dry period samples showed no differences in Asp f 1 levels. These results indicate that even in the presence of measurable fungal concentrations, background levels of Asp f 1 are low. Nonindustrial office buildings devoid of indoor air quality issues were not observed to have significant levels of the Asp f 1 allergen in the geographical region studied.

Beryllium is an ubiquitous element in the environment, and it has many commercial applications. Because of its strength, electrical and thermal conductivity, corrosion resistance, and nuclear properties, beryllium products are used in the aerospace, automotive, energy, medical, and electronics industries. What eventually came to be known as chronic beryllium disease (CBD) was first identified in the 1940s, when a cluster of cases was observed in workers from the fluorescent light industry. The U.S. Atomic Energy Commission recommended the first 8-hour occupational exposure limit (OEL) for beryllium of 2.0 microg/m3 in 1949, which was later reviewed and accepted by the American Conference of Governmental Industrial Hygienists (ACGIH), the American Industrial Hygiene Association (AIHA), the American National Standards Institute (ANSI), the Occupational Safety and Health Administration (OSHA), and the vast majority of countries and standard-setting bodies worldwide. The 2.0 microg/m3 standard has been in use by the beryllium industry for more than 50 years and has been considered adequate to protect workers against clinical CBD. Recently, improved diagnostic techniques, including immunological testing and safer bronchoscopy, have enhanced our ability to identify subclinical CBD cases that would have formerly remained unidentified. Some recent epidemiological studies have suggested that some workers may develop CBD at exposures less than 2.0 microg/m3. ACGIH is currently reevaluating the adequacy of the current 2.0 microg/m3 guideline, and a plethora of research initiatives are under way to provide a better understanding of the cause of CBD. The research is focusing on the risk factors and exposure metrics that could be associated with CBD, as well as on efforts to better characterize the natural history of CBD. There is growing evidence that particle size and chemical form may be important factors that influence the risk of developing CBD. These research efforts are expected to provide data that will help identify a scientifically based OEL that will protect workers against CBD.

The occupational exposure limit of 2.0 microg/m3 for beryllium has been used in the workplace since the late 1940s. In particular, the adequacy of the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value (TLV) for beryllium has recently come into question. The symposium "Beryllium: Effect on Worker Health" was convened in September 1999, to bring together leading scientists to present and discuss current research activities on beryllium exposure and chronic beryllium disease (CBD). One of the key questions to be resolved at the symposium was, "Is there a sufficient understanding of exposure and the cause of CBD that would allow us to develop a TLV that we believe would prevent disease?" Seven scientists presented information regarding the current understanding of the disease, possible causes, and ongoing research. The topics were (1) biomonitoring approaches and their relationship with clinical effects, (2) historical and current exposure assessments, (3) sampling methods and aerosol characterization, and (4) epidemiology. Six basic hypotheses regarding the relationship between exposure to beryllium and CBD were generated from the information presented at the symposium. The six hypotheses that are related to issues such as beryllium form, particle size, industrial hygiene practices, extrapulmonary routes of exposure, and genetic susceptibility also appear to be the focus of ongoing and likely future research initiatives. This article summarizes both the presentations made at the meeting and the hypotheses generated. It is expected that an understanding of these issues should explain the inconsistent dose-response relationship observed between exposure and CBD. The ongoing and planned research is anticipated to provide sufficient data within two to three years to develop one or more scientifically sound TLVs for the different chemical forms of beryllium.