Evaluation of two lead-based paint removal and waste stabilization technology combinations on typical exterior surfaces.

A study was conducted to demonstrate the effectiveness of a wet abrasive blasting technology to remove lead-based paint from exterior wood siding and brick substrates as well as to evaluate the effectiveness of two waste stabilization technologies to stabilize the resulting blast media (coal slag and mineral sand) paint debris thereby reducing the leachable lead content. The lead-based paint removal technology effectiveness was determined by the use of an X-ray fluorescence (XRF) spectrum analyzer (L- and K-shell). The effectiveness of the technologies to stabilize the debris was evaluated through the toxicity characteristic leaching procedure (TCLP). Wet abrasive blasting effectively removed the lead-based paint coating from both the wood and brick substrates to below the US Department of Housing and Urban Development Guideline (1mg/cm(2)) with no minimal or no damage to the underlying substrates (P<0.0001). The mean area air levels of lead-containing particulate generated during paint removal were significantly below the personal exposure limit (PEL) (P<0.0001). However, the mean personal breathing zone lead levels were approximately three times higher than the PEL. Neither of the two stabilization technologies consistently stabilized the resultant paint debris to achieve a leachable lead content below the RCRA regulatory threshold of <5 mg/l.

Use of risk assessment methods in the certification of decontaminated buildings.

Accidental events such as fires, explosions, and leaks often result in large-scale contaminations of buildings with toxic chemicals. After decontamination, the certification for original use requires testing for residual contamination. The two basic kinds of sampling plans in use up to recently both fall short of the required performance. Their deficiencies are analyzed in terms of the scientific questions implicit in both the sampling plan and the subsequent statistical evaluation. A sampling strategy of a new kind is proposed and discussed in the same context. It is motivated by concern for the long-term safety of the building's occupants and is, therefore, based on factors important in risk assessment. Three different sampling plans are derived in the framework of this methodology, two of which have already been used in actual certification proceedings.

Common-source community and industrial exposure to trichloroethylene.

In July 1979, 1,900 gallons of trichloroethylene (TCE) were released into ground and surface water from a pipe manufacturing plant in Montgomery County, Pennsylvania. To evaluate community and occupational exposure to TCE, we conducted environmental and medical surveys. In well water samples obtained in August 1979 within 1 km of the factory, TCE concentrations ranged to 183,000 parts per billion (ppb); EPA's proposed guideline for TCE in drinking water is 5 ppb. Levels of TCE declined with distance from the plant and decreased in the months following the spill. However, lower level TCE contamination was widespread and persistent, suggesting multiple releases. Within the plant, mean time-weighted occupational exposure to TCE of degreaser operators was 205 mg/m3; the recommended time-weighted exposure limit is 135 mg/m3. Mean short-term exposure was 1,084 mg/m3; the recommended short-term limit is 535 mg/m3. Seven of 9 exposed workers reported drowsiness, dizziness, or mental confusion. In exposed workers, mean urinary excretion of TCE metabolites rose from 298 micrograms/L pre-shift to 480 micrograms/L post-shift. On re-evaluation of the factory following improvements in ventilation and work practices, mean time-weighted occupational exposure to TCE had decreased to 84 mg/m3 and short-term exposure to 400 mg/m3; symptom frequency and concentrations of urinary TCE metabolites also were reduced. This episode demonstrates that community and occupational exposure to chemical toxins may share a common origin.

Chronic beryllium disease in a precious metal refinery. Clinical epidemiologic and immunologic evidence for continuing risk from exposure to low level beryllium fume.

Five workers at a precious metal refinery developed granulomatous lung disease between 1972 and 1985. The original diagnosis was sarcoidosis, but 4 of the workers were subsequently proved to have hypersensitivity to beryllium by in vitro proliferative responses of lymphocytes obtained by bronchoalveolar lavage. Review of medical records of coworkers and extensive industrial hygiene surveillance of the plant demonstrated that 4 cases occurred in the furnace area where air concentrations of beryllium fume were consistently below the permissible exposure limit of 2 micrograms/M3. A single case has been recognized from parts of the refinery where exposures to cold beryllium dust often exceeded the standard by as much as 20-fold. These data demonstrate that chronic beryllium disease still occurs and confirm the importance of specific immunologic testing in patients suspected of having sarcoidosis but with potential exposure to beryllium. The data raise concern about the adequacy of modern industrial controls, especially in the setting of exposure to highly respirable beryllium fume.

Failure of enzyme encapsulation to prevent sensitization of workers in the dry bleach industry.

BDE added to dry bleach have been associated with immunologic sensitization and development of clinical allergic disease in detergent workers and occasionally in consumers. However, improved dust control and modification of the manufacturing process through encapsulation of enzyme were believed to have reduced or eliminated these problems. To determine whether or not immunologic sensitization could still develop in the detergent industry, we studied employees of a dry bleach manufacturing plant that incorporated encapsulated BDE into a consumer product. We performed air sampling for enzyme dust and total particulates, administered questionnaires, conducted physical examinations, and spirometry in 13 currently exposed, two previously exposed and nine nonexposed, employees. To assess sensitization status, RAST and ELISA were performed. Air concentrations of enzyme dust ranged from 0.002 to 1.57 micrograms/m3; all of these levels were below the TLV of 3.9 micrograms/m3. Positive BDE-specific RAST results (3.4%, 4.4%, and 8.0% binding) were obtained in three of 12 currently exposed workers. Results of personal breathing-zone air sampling indicated that these workers had high dust-exposure levels. Specificity of RAST was verified by RAST inhibition with BDE. BDE-RAST binding was not significantly elevated in the nonworkers (range: 0.6% to 1.4% binding). Positive results for specific IgG by ELISA were obtained in four of 12 currently exposed and in one of two previously exposed workers but in none of the nonexposed workers. We conclude that immunologic sensitization can develop after occupational exposure to encapsulated BDE in the dry bleach industry. We have not proved, however, that this immunologic reactivity is related to clinical sensitivity.

Worker exposure to organic vapors at a liquid chemical waste incinerator.

The extent of employee exposure to organic vapors at a liquid/fluid chemical waste incinerator facility was assessed by means of a preliminary survey. The study was conducted at a facility owned by the Metropolitan Sewer District of Greater Cincinnati, Cincinnati, OH. The incineration unit employs a rotary kiln and a cyclone furnace (liquid injection) with a common combustion chamber. A wide variety of liquid industrial chemical wastes are accepted in tank truck quantities. Low flow air pumps were used to collect breathing zone and general area samples on standard 150-mg charcoal tubes. The samples were analyzed by a gas chromatograph equipped with a flame ionization detector. Benzene, methyl ethyl ketone (MEK), toluene and xylene, solvents common to many of the wastes accepted, were selected for determination. The data indicate that the routine operation of this liquid industrial waste incinerator facility results in worker exposure considerably less than the action level (50% of the health standard) for all compounds tested, except benzene. Some workers were at risk of overexposure to benzene if the NIOSH-recommended criteria are used, but not when the OSHA and ACGIH criteria are used. The highest exposure routine operations were cleaning pump strainers after receiving wastes and benzene distillations conducted in the laboratory. The non-routine operation of storage tank entry, which occurred once during the study, resulted in the highest potential exposure of any operation.

The efficacy of a population-based comparison group in cross-sectional occupational health studies.

The availability and the choice of appropriate comparison groups are essential for valid occupational epidemiologic studies. Too often, however, adequate comparison groups cannot easily be found within a workplace environment or extracted from the general population. An evaluation of the efficacy of using a pool of comparison subjects from the health and Nutrition Examination Survey (HANES) was performed on data gathered by the National Institute for Occupational Safety and Health in 1979. Comparison groups from the HANES pool were derived for 246 workers at four different commercial/industrial facilities in the Niagara Falls, New York, area and the comparability between the groups was assessed for several demographic, behavioural, and biomedical variables. The HANES groups exhibited a high degree of comparability with regard to most variables, excluding ancestry. The HANES pool may serve as a useful source of subjects to allow for the comparison of disease rates where occupational exposure is the key distinguishing feature between groups.

Red spots among flight attendants: observation--a valuable investigative tool.

The National Institute for Occupational Safety and Health and the Bureau of Epidemiology of the Center for Disease Control investigated episodes of red spots appearing on the skin of flight attendants during various Eastern Airlines flights in the first three months of 1980. Review of 132 cases reported during January and February showed that 91 different flight attendants had been affected; 96% of cases had occurred on flights between the New York and Miami metropolitan areas, and 90% on a single type of aircraft. Although some reports mentioned burning, nausea, and headache in association with spots, most reports involved only the occurrence of bright red spots that could be wiped or washed off. Studies of work practices and procedures of flight attendants revealed that the red spots were caused by red ink flaking off the life vests during demonstrations of the use of the vests in preflight safety instructions. The demonstration vests were labelled with ink containing a litholrubine chrome molybdate orange pigment. Following removal of the implicated vests from all Eastern Airlines aircraft, no further cases have appeared.

Occupational exposure to hexachlorocyclopentadiene. How safe is sewage?

In March 1977, a large volume of the industrial chemical hexachlorocyclopentadiene (HCCPD) was dumped into a municipal sewage system in Kentucky. We evaluated the health effects of exposure to HCCPD in 145 sewage treatment plant workers. We found that 85 (59%) had noted eye irritation, 65 (45%) had headaches, and 39 (27%) had throat irritation. Symptoms occurred throughout the plant; however, highest attack rates occurred in primary sewage treatment areas. Medical examination of 41 employees three days after the plant was closed showed proteinuria and elevation of serum lactic dehydrogenase levels; these findings were not present three weeks later. This episode demonstrates the toxicity of HCCPD and emphasizes the vulnerability of sewage workers to chemical toxins in wastewater systems.

Phototoxicity occurring during the manufacture of ultraviolet-cured ink.

Four workers employed in the manufacture of ultraviolet-cured inks complained of photosensitivity characterized by an intense burning sensation during sun exposure. Three of these workers developed dermatitis on exposed areas following sun exposure. Six compounds used as photoinitiators in the ink formulations were found to absorb solar ultraviolet radiation. Two preparations of mixed isomers (ortho and para) of amyl dimethylaminobenzoate were found to be phototoxic to Ehrlich ascites cells in vitro and to produce diphasic phototoxic reactions in vivo after topical application on symptomatic workers, asymptomatic workers, or previously unexposed subjects. These responses could be prevented in two subjects by the application of a 10% sulizobenzone sunscreen prior to sun exposure. Two other photoinitiators, Michler's ketone and thioxanthone were phototoxic in vitro but not after topical application in vivo.

Allergic contact dermatitis from ultraviolet cured inks. Allergic contact sensitization to acrylates.

Eight men employed in the manufacture of ultraviolet cured inks developed allergic contact dermatitis predominantly on the exposed areas. Patch testing revealed sensitization to trimethylol propane triacrylate in seven employees, to 1,6-hexanediol diacrylate in six employees, to pentaerythritol triacrylatylate in four employees and to epoxy acrylate oligomers in three employees. Either cross-sensitization or concomitant sensitization may have accounted for the multiple reactions in several employees. One sensitized employee was patch tested with four different commercially available epoxy acrylate oligomers and reacted only to two, suggesting that variations possibly in chain length between these oligomers are important variables in the allergic reactions. The polyfunctional acrylic monomers and certain epoxy acrylate oligomers should be handled carefully to avoid the development of allergic contact dermatitis.