249
OCCUPATIONAL EXPOSURES DURING THE PREPARATION OF PSEUDO NARCOTICS FOR CANINE
TRAINING.
C. Dowell, CDC NIOSH, Cincinnati, OH.
NIOSH received a request for a health hazard evaluation at the U.S. Customs and Border Protection’s Canine Enforcement Training Center in Front Royal, Va. The request concerned potential exposures from the preparation of pseudo narcotics.
Seven personal breathing zone (PBZ) air samples were collected for total particulates on workers in the mix room. Nine general area (GA) air samples were collected for total particulates in the mix and package rooms. Two PBZ air samples were collected for acetic acid on workers in the mix room and four GA air samples were collected in the mix and package room. Three GA air samples were collected for benzaldehyde and piperonal and four GA air samples for methyl benzoate in the mix room.
The particulate contained cab-o-sil® and microcrystalline cellulose. All of the total particulate PBZ air samples collected on workers in the mix room exceed the OSHA PEL for particulates not otherwise classified and the ACGIH TLV for cellulose. Their concentrations ranged from 21 to 110 mg/m3 with an average of 43 mg/m3. Workers lean forward and place their heads inside drums, scooping out powder near the bottom. This accounts for the high airborne dust concentrations. One of two acetic acid PBZ air samples collected on workers in the mix room exceed the NIOSH REL, OSHA PEL, and ACGIH TLV. This sample was collected on the worker who measures acetic acid. All other air samples collected were below relevant evaluation criteria.
There is a potential for excessive particulate and acetic acid exposure in the mix room of the pseudo drug building. Based on a description of other work activities not directly observed, there is also a potential for respiratory hazards during the chopping of marijuana bales. Recommendations included ventilation improvements, modified work practices, and use of respiratory protection.
250
OCCUPATIONAL HEALTH AND INDUSTRIAL HYGIENE CONSIDERATIONS RELATED TO CASES OF
HISTOPLASMOSIS AMONG WORKERS AT A CORN PROCESSING FACILITY.
B. King, G. Burr, NIOSH, Cincinnati, OH.
CDC received a request from the Nebraska Health and Human Services System to conduct an investigation of possible cases of histoplasmosis among the employees at a 650-acre corn processing facility in rural Nebraska in February 2004. A site visit was made to address concerns that a second outbreak of histoplasmosis was occurring among the employees at the work site, following one that had occurred in August 2003 in which 43 clinically- or laboratory-confirmed cases were identified. In that outbreak, soil excavated for pipe repair in an area of the facility associated with a large accumulation of bird droppings was a likely cause of aerosolization of H. capsulatum spores and thus, the possible site of the employees’ exposures. CDC/NIOSH representatives participated in the February 2004 investigation by addressing industrial hygiene and occupational health related issues. This included providing guidance to the company to identify worker activities that may be at higher risk for exposure, the proper use of personal protective equipment (PPE) required for these activities, and recommendations for preventing future outbreaks. CDC/NIOSH representatives conducted a walkthrough of facilities to identify accumulations of bird droppings and discuss job activities and protocols with employees at these locations. We met with the health and safety managers to review a draft plan developed to characterize activities regarding the risk for exposure to H. capsulatum spores, and the corresponding PPE that would be required. We also reviewed the adequacy of the written respiratory protection program. Recommendations provided to the company included proper employee training regarding the hazard and the company’s policies on the selection of PPE (particularly respiratory protection) for work categorized as higher/lower/minimal risk; excluding birds from entry to buildings by sealing all entry points; updating their written respiratory protection program; and ensuring proper maintenance of building and ventilation systems.
251
ISOFLURANE EXPOSURE CASE STUDY: ONE COMPANY’S APPROACH.
J. Dunbarr, Chiron Corporation, Emeryville, CA.
The purposes of this case study include (1) measurement of personal and area concentrations where isoflurane is used within the facility, (2) identify trends that may be likely to contribute to increased exposures, (3) identify improvements that can be made within the processes to decrease exposure for employees working around isoflurane, and (4) implementing these improvements into the program and looking ahead to future challenges.
The study was set in our Comparative Medicine Facility and ranges from March 2001 to present. There are approximately 30 employees whom may work with isoflurane at any given time, and 17 rooms within this facility in which isoflurane may be worked with. Many of these employees are working with isoflurane on a daily basis, ranging anywhere from 30 minutes up to four hours, depending on the task. A total of over 100 personal and area samples have been taken within this study. There are eight categories in which sample results have been classified by task. The majority of the work with isoflurane at our facility includes surgeries, injections, blood draws, and microchipping during the studies.
Due to the frequency and quantity of isoflurane used in our facility, it became essential to identify and present any changes that could be recommended to the group and implemented into the process, which would aid in minimizing the employee’s exposure.
This presentation focuses on samples taken, methods, individual and task-related isoflurane results (including averages), lessons learned, and looking ahead.
252
LEAD AND NOISE EXPOSURES DURING OPEN ABRASIVE BLASTING ON TWO STEEL BRIDGES.
C. Kirkham, S. McAllister, Cal/OSHA, San Francisco, CA.
Bridge retrofit work has increased in the last decade. The literature fails to provide sufficient characterization of the seemingly high noise and lead exposures during bridge open abrasive blasting. Blasters on some retrofits are experiencing medical-removal blood lead levels, and hearing loss is often not monitored. PPE is commonly relied upon rather than engineering and administrative controls. Two painting contractors open abrasive blasted on 1940’s-era bridges and were evaluated for noise exposures, lead exposures, and the sufficiency of commonly used blasting PPE. Spot paint removal to “Near White Blast SP10” was conducted using copper slag grit in large negatively-pressurized containments accommodating one to three blasters. Blasters used supplied-air continuous-flow rubberized canvas hood respirators, with an assumed protection factor of 1000, and foam earplugs with NRRs of approximately 30 dB. Calibrated noise dosimeters and 3-mm MCE cassette/pumps were placed outside of all PPE, except during two noise evaluations. All outside-hood 8-h TWA noise exposures were above 100 dBA, and half were between 109 and 115 dBA. Two under-hood 8-h TWAs were 102 and 108 dBA. Using an estimation of workplace attenuation ((NRR–7 dB)/2), earplugs failed to reduce 8-h TWA exposures to less than 90 dBA. Average lead contents of blasted paint samples from bridges #1 and #2 were 29% (3–44%, n = 11) and 22% (10–29%, n = 5) respectively. Of 51 blasting cassettes, 12 were greater than one half the IDLH level of 100,000 ug lead/m3, and five were at or above IDLH. Respirators were not approved for IDLH. The geometric mean of 8-h TWA lead exposures on bridge #1 was 23,371 ug/m3 (9881–56,781 ug/m3, n = 9), and on bridge #2 was 5569 ug/m3 (2197–38,579 ug/m3, n = 7). One of the 16 blaster’s 8-h TWAs exceeded the protective capability of his respirator (50,000 ug/m3) and four exceeded half of that value.
253
WORKER EXPOSURES TO OZONE AND OTHER CONTAMINANTS DURING TIG AND MIG WELDING.
G. Burr, R. Sollberger, C. Achutan, NIOSH, Cincinnati, OH.
NIOSH evaluations were conducted at a company producing oil coolers used in the U.S. Army main battle tank. Workers described health effects during tungsten inert gas (TIG) and metal inert gas (MIG) welding on aluminum oil coolers, including burning eyes, sore throats, headaches, sinus problems, and exhaustion. Employees were also concerned about discoloration on their welding visors. Air sampling was performed for ozone, metals (specifically aluminum), trichloroethylene (TCE, used in a nearby degreaser), and phosgene (a possible combustion product when chlorinated hydrocarbon comes in contact with a flame or very hot metal). During the initial survey the highest exposures were to ozone, ranging up to 0.7 parts per million (ppm) for short-term (five minute) exposures, exceeding the NIOSH ceiling limit for ozone of 0.1 ppm. Higher concentrations were measured during MIG welding (up to 0.7 ppm) compared to TIG welding (< 0.05 to 0.1 ppm). Exposures to other contaminants were well below occupational exposure limits (OELs). A brownish-red residue that accumulated on the welding visors contained iron and copper. During the follow-up survey, full-shift ozone concentrations ranged from not detected to 0.08 ppm, while short-term (five minute) concentrations were not detectable. However, no MIG welding was performed during the follow-up survey. Detector tube samples for TCE revealed short-term concentrations ranging from 5 and 100 ppm in the vicinity of the degreaser. All other contaminant levels were below their OELs. Phosgene was not detected during either survey. Recommendations to reduce ozone exposures included installing engineering controls (more local exhaust ventilation, larger exhaust hoods, and more general room ventilation), limiting the amount of welding during a workday, and using respiratory protection while implementing these engineering or administrative controls. For the degreaser operation recommendations included performing full-shift sampling for TCE and providing additional operator training and personal protective equipment.
254
EXPOSURE TO METAL FUMES DURING SCRAP METAL RECYCLING.
M. Rodriguez, CDC/NIOSH, Cincinnati, OH.
The National Institute for Occupational Safety and Health (NIOSH) received a health hazard evaluation request from a large scrap metal recycling company to evaluate whether their employees were overexposed to lead and other metals and if they needed to comply with the OSHA Lead standard, 29 CFR 1910.1025. Lead and other hazardous metals were suspected in the base metal, alloys, and preservative coatings on the recycled scrap. Contamination of clothing and hands was also a concern since these conditions may create an ingestion hazard and may contaminate the worker’s car, home, and family. The two job categories evaluated were Burners, cutting large pieces of scrap metal usually several inches thick with an oxygen/propane torch, and Plate Cutters, cutting steel plates less than one inch thick with the same type of torch. NIOSH investigators collected 27 personal air samples for elements over three consecutive workdays, 13 on the Burners and 14 on the Plate Cutters. Of the 13 samples collected on the Burners, 12 were over the OSHA permissible exposure limit (PEL) or action level (AL) for lead. Several Burners exceeded the OSHA PEL for cadmium, copper, and arsenic. In addition, three Burners exceeded the NIOSH recommended exposure limit for nickel. One Plate Cutter exceeded the OSHA PEL for lead and four, the AL. Wipe samples were collected from employees’ hands, personal protective equipment (PPE), and work surfaces and analyzed for lead and other metals. Lead was found on the workers’ hands, PPE, and other surfaces in concentrations ranging from none detected to 760 µg per sample. The employer was informed of the requirements in OSHA’s substance-specific standards, specifically the need for engineering controls, use of showers, maintaining clean work surfaces, and use of respiratory protection until engineering controls are implemented.
255
EVALUATION OF WORKER EXPOSURES DURING THE MANUFACTURING OF HIGH QUALITY
CORROSIVE RESISTANT STAINLESS STEEL PRODUCTS AND FABRICATED PIPING SYSTEMS.
R. Hall, D. Rhodes, E. Page, CDC/NIOSH, Cincinnati, OH.
NIOSH conducted a health hazard evaluation of worker exposures during the welding and manufacturing of stainless steel products and fabricated piping systems. Worker representatives expressed concerns about potential carcinogenic effects from exposure to nickel and chromium. Personal breathing zone air sampling was conducted during cutting, welding, and grinding for elements (including nickel and chromium), total welding fumes, hexavalent chromium, ozone, nitrogen dioxide, and carbon monoxide. Samples indicated the potential for some workers to be exposed to nickel and hexavalent chromium concentrations above the NIOSH REL, and to manganese above the ACGIH® TLV®. PBZ results indicated the highest concentrations for nickel, manganese, and hexavalent chromium occurred during welding operations inside large stainless steel pipes or while welding fins on a large stainless steel pipe. Ozone results indicated concentrations exceeded the NIOSH REL ceiling limit, and indicate the potential to exceed ACGIH and OSHA criteria (if consistent welding is accomplished throughout the work shift) during welding operations inside pipes. Although the potential for exposure to Ni and Cr exists, at the time of our evaluation the types of cancers linked to these substances have not been reported among current or former employees. Recommendations were provided to help reduce exposures.
256
DIESEL-POWERED VEHICLE EXHAUST VOLUMES IN U.S. ARMY MAINTENANCE FACILITIES.
G. Berckman, U.S. Army CHPPM-North, Fort George G. Meade, MD.
The currently-used guidance for local exhaust ventilation (lev) design in diesel-powered vehicle maintenance facilities was extrapolated from empirically determined data collected at some point in the past. Diesel technology has come a long way since these standards were written, especially with the advent of the wide-spread use of turbochargers, and it is unclear whether these currently-used designs are adequate for proper contaminant removal. The first step in validating the efficacy of the current designs (or in devising new ones) is to determine exhaust flow volumes from the vehicles whose emissions we are attempting to control. This volumetric flow data can be used to validate currently-used design criteria or to prepare new lev standards for such vehicle emissions. Based upon the data collected during this project, the currently-used criteria for lev for turbocharged diesel-powered vehicles in Army maintenance facilities is excessive. Such criteria should be revised downward to a lev flow rate of 1320 cfm for most facilities which service commonly used vehicles such as commercial utility cargo vehicles, high-mobility military vehicles, and M816 wreckers. For shops that service larger equipment, such as M916 20-ton tractors, the required lev flow rate should be revised to 1740 cfm. It is the author’s intent that these data will be used, as stated above, to validate currently-used design criteria, or, failing that, to prepare new lev standards for such vehicle emissions.
257
AIRPORT “CHECKED BAGGAGE” SCREENER EXPOSURE TO INTERNAL COMBUSTION ENGINE
EXHAUST PRODUCTS.
M. Methner, NIOSH, Cincinnati, OH; L. Delaney, NIOSH, Atlanta, GA.
The Transportation Security Administration (TSA) requested the National Institute for Occupational Safety and Health (NIOSH) to evaluate airport “checked baggage” screeners’ exposure to diesel particulate matter (DPM), carbon monoxide (CO), nitric oxide, nitrogen dioxide, and other products of combustion. Exposures were believed to be related to internal combustion baggage tug engines operating near the screeners. Four international airports (Palm Beach, Miami, Baltimore-Washington, and Dulles) were selected for air monitoring studies. The selection criteria included the following: (1) prior complaints from TSA workers regarding exhaust emissions; and (2) the location and arrangement of the check baggage stations (open verses enclosed screening areas). Each airport study was designed to collect the same information so that air monitoring data could be compared across airports. Personal breathing zone (PBZ) and ambient air samples were collected and analyzed in accordance with appropriate NIOSH methods. All PBZ measurements were compared to their respective occupational exposure limits. No respiratory protection was worn by any worker in any of the airports studied. Only 2 of the 72 (3%) DPM samples exceeded 20 micrograms per cubic meter (ug/m3), (the former ACGIH exposure limit and the current California limit for DPM). Average DPM values ranged from 6–14 ug/m3. Average CO levels ranged from 0.6 to 5.3 parts per million (ppm), well below the NIOSH Recommended Exposure Limit of 35 ppm. Samples collected for other substances of interest ranged from very low to nondetectable. Exhaust emission testing on tugs at two airports found high levels of hydrocarbons and CO, which was related to poor maintenance.
258
NOISE EXPOSURE ASSESSMENT OF AIRPORT SCREENERS DURING CHECKED BAGGAGE SCREENING.
L. Delaney, NIOSH, Atlanta, GA; R. Tubbs, M. Methner, NIOSH, Cincinnati, OH.
Background. Beginning in 2003, Transportation Security Administration (TSA) employees began inspecting all airline passengers and property for explosives and incendiaries. Most checked passenger bags are screened in the ramp area of the airports in areas previous not occupied by employees for a full eight-hour shift. A series of conveyor belts deliver bags to the various baggage areas where TSA employees manually load them onto a conveyor that routes each bag through an Explosive Detection System. After examination, airline personnel transfer the bags to carts attached to tugs for delivery to the aircraft. TSA employees and management were concerned about exposures to high noise levels generated from tugs, jets, conveyor belts, and baggage carousels in the checked baggage screening area. Methods. Four airports were selected for inclusion in the study based on size, location of screening areas, and baggage screening volume. Full-shift personal noise monitoring was conducted in the areas of concern and area noise measurements were collected to characterize the noise source. Findings and Conclusions. Of the 56 personal full-shift samples for noise, none exceeded the Occupational Safety and Health Administration’s Permissible Exposure Limit. There were 12 instances where the 8-hr TWA exposures exceeded the National Institute for Occupational Safety and Health criterion. Generally, the noise exposures to which TSA employees were subjected during their work activities did not pose a risk for occupational noise-induced hearing loss. Major noise sources identified were the ventilation system, aircraft, airline tugs and carts, and the movement of luggage from conveyors onto the screening machines and from the machines to tables for additional inspection, or onto the airlines’ conveyors for delivery to the aircraft. Recommendations to further reduce noise levels were provided to attempt to help improve communication between employees.
259
DETERMINING SOUND ATTENUATION CHARACTERISTICS OF HPDS EXPOSED TO IMPULSE NOISE.
D. Carpenter, P. Parrish, D. DeCamp, S. Purdy, I. Rybczynski, R. Shumate, A. Wells, AFIOH, San Antonio, TX.
Impulse noise presents unique problems for hearing protection use. Current hearing protective devices (HPDs) are typically assigned an attenuation rating (Noise Reduction Rating or NRR) for use in determining the attenuation characteristics with continuous noise levels. Regulatory guidance has identified impulse levels that are considered to be hazardous. However, there are no established attenuation values (NRR) for HPDs tested against an impulse noise stimulus and no defined method for the selection of appropriate HPDs for a given impulse noise level.
This study utilized an acoustic manikin (B&K Type 4128C) to measure the attenuation values of various HPDs, including earmuffs and earplugs. The manikin was exposed to controlled presentations of impulse noise in an outside environment. The HPD attenuation levels were determined by measuring the differences in sound pressure levels (SPLs) at the manikin’s eardrum microphone with and without the HPDs in place. The SPLs were captured and analyzed by use of a high-speed data acquisition board utilizing software that simulates a digital storage oscilloscope, producing “snapshots” of the noise pulses. The results of this study characterized the manufacturer reported NRR of various HPDs to continuous and impulse noise.
260
ASSESSING HEALTH AND SAFETY OF HEALTH CARE WORKERS—EVALUATION OF SURVEY METHODS
IN A REGIONAL MEDICAL CENTER.
G. Piacitelli, J. Boiano, K. Sieber, NIOSH, Cincinnati, OH; J. Catalano, N. Heyer, B. Payn, Battelle, Seattle, WA.
The National Exposures at Work Survey is intended to collect descriptive data from employees regarding occupational health and safety practices and perceptions, potential exposures, and interventions. The feasibility of collecting this information within the health care industry using a self-administered employee questionnaire was evaluated in a medical center. The questionnaire consisted of a core module addressing general issues (e.g., violence, stress, sharps) and 10 hazard-specific modules (e.g., hazardous drugs, anesthetic gases, sterilants). The questionnaire could be completed using either a multimodule paper version or a seamless web-based version. Approximately 750 employees were divided into three groups. “Targeted” employees (Group 1, n = 295), determined a priori to have potential exposure to targeted hazards (e.g., oncology nurses to hazardous drugs), received a letter with a core module and one or more hazard modules in paper version. “Non-targeted” employees received either a letter with a paper core module (Group 2, n = 229) or only a letter with instructions for requesting the paper core (Group 3, n = 224); both of these groups were instructed to request appropriate hazard modules based upon screening questions. All three groups received instructions for alternatively accessing the web-based version. Overall, 53% of sampled employees completed the survey; response rates among common occupations ranged from 47 (pharmacy personnel) to 58% (medical supply technicians). When provided, an employee was more likely to complete the paper version rather than accessing the web-version (76 versus 24%). However, 89% of employees who received only a letter tended to choose the web-based questionnaire. If an employee was instructed to obtain hazard modules after completing screening questions in the paper core module, only 7% did so. This was not a problem in the web-based version, which was seamless with respect to additional modules. These results suggest a self-administered web-based survey is an accepted and efficient method to query workers.
261
DUPONT BLADDER CANCER SCREENING FOR POST-EXPOSURE COHORTS.
B. Dawson, DuPont Company, Wilmington, DE; T. Mason, University of South Florida, Tampa, FL.
This paper reports results of a bladder cancer screening program for pensioners/post-exposure active employees from three manufacturing groups: dyes, aramids, and elastomers with previous potential exposure to benzidine, beta-naphthylamine, alpha-naphthylamine, 4-ADP, MOCA, 4-nitrophenyl, or o-toluidine. The annual screening includes 14 consecutive days of self-testing for hematuria using a chemically-treated paper strip. Urine, collected on day 1 of screening, is sent to one central laboratory facility for quantitative assessment of hematuria and cytologic classification. Participants are referred for urologic diagnostic evaluation if any of the following results are found: three or more red blood cells per high-powered field, Class 3 or greater cytology, and/or at least one day positive for hematuria during the 14-day self-testing. To date, 1012 persons from four sites have been notified, and 785 have enrolled (77.5%). Seventy-four percent of the enrollees are 60 years of age or older. This presentation will report on two cycles of screening. In year one, 28.7% of the participants tested positive and were referred for diagnostic evaluation. In year two, this percentage was 23.5. For quantitative hematuria, the percents positive were 11.3 (year 1) and 8.7 (year 2). For urinary cytology, the percents positive were 7.5 (year 1) and 5.6 (year 2). Final diagnoses among those referred for year 1 are: three incident transitional cell carcinomas of the bladder, 18.9% were “serious but treatable conditions;” for year 2, one incident and one recurrent transitional cell carcinoma of the bladder, 15.8% were “serious but treatable.” Results to date are consistent with previous screens among active employees. We maintain a high participation rate owing to personal follow-up by our team, as well as a 24/7 toll-free number that is available to all participants. Our results, we believe, will encourage reconsideration of recommended screening programs for workers who have been exposed.
262
NORTH CAROLINA: TRENDS IN AGRICULTURAL COMPLIANCE, 2000–2004.
R. Luginbuhl, North Carolina Department of Labor, Raleigh, NC.
The Agricultural Safety & Health Bureau of the North Carolina Department of Labor has conducted inspections of farm worker migrant housing since 1990. Inspections are conducted prior to housing occupancy. These inspections are regarded as consultative visits. No fines or citations are issued as a result of these inspections; the owner/operator is required to come into compliance in order to be certified. Over 1600 sites in 88 N.C. counties are certified annually under this program.
In addition to preoccupancy inspections, compliance inspections are also conducted by this Bureau. These inspections include agricultural fatalities, accidents, complaints, and referrals. These inspections may carry citations and monetary penalties. General schedule inspections have been added to the compliance list, primarily in response to complaints and referrals regarding lack of field sanitation, OSHA PART 1928.110. Computer generated random samples were selected from the computer database of registered growers for the past three years. Approximately 60 general schedule compliance inspections are conducted annually, in addition to the other agricultural compliance inspections. Inspectors are each given a number of the general schedule inspections to complete during the months of July, August, and September. While on the inspection, questions regarding housing and pesticide application, OSHA PART 1910.1200, are made in addition to the field sanitation. If workers make complaints regarding their farmworker housing, provided as a condition of farm work, or pesticide application, the inspection is expanded to accommodate their workplace safety concerns. This poster will illustrate the Bureau compliance findings during the past five years, 2000–2004. Summary graphs and explanations are shown listing compliance findings and trends for this period. Recommendations are made concerning future compliance efforts based on these results. Comments and concerns of both farm workers and members of the grower community are provided as well, indicating the education/outreach efforts needed.
263
TRANSFORMATION OF DI-ETHANOLAMINE (EA) AND TRI-EA INTO EAS WITH LOW MOLECULAR
WEIGHT IN SOLUBLE METALWORKING FLUIDS.
D. Park, Korea National Open University, Seoul, Republic of Korea; S. Kim, Wonjin Institute of Occupational and Environmental Health, Seoul, Republic of Korea.
Alkanolamines or ethanolamines (EA)-triEA (TEA), di-EA(DEA), and mono-EA(MEA) are used in soluble metalworking fluids (MWFs) to stabilize pH or inhibit corrosion. These EAs have similar chemical structure except for molecular weight. Two kinds of experimental studies were conducted to examine if EAs were vaporized and transformed to other EAs with lower molecular weight. Vaporization test using thermostat bath found that only MEA could be vaporized at a temperature lower than 60°C. The vaporization rate of MEA increased markedly from 0.19 mg/m2.min at 23.5°C to 8.04 mg/m2.min at 60°C. This result indicated that MEA might be vaporized even at work operations where MWFs are running around room temperature. Closed chamber test that was used to test the vaporization and degradation of EAs under high temperature found that most of MEA injected was completely recovered. However, only 13.32% of DEA and no TEA was recovered. EAs that never injected were newly detected, which concluded that EAs with high molecular weight could be transformed to new EAs with low molecular weight due to degradation by extreme heat. Further field study is needed to identify physical factors that can cause the formation of new EAs in work conditions or operations generating extreme heat.
264
ASSOCIATION OF AIR TOXICS EXPOSURE AND ASTHMA HOSPITALIZATION IN NEW JERSEY.
S. Tsai, S. Miller, J. Fagliano, M. Berry, J. Wallace, NJ DHSS, Trenton, NJ; L. Lim, NJ Department of Environmental Protection, Trenton, NJ.
Withdrawn
265
CARBON DIOXIDE INFILTRATION INTO A HOME.
J. Harrison, C. Rao, L. Benaise, NIOSH, Morgantown, WV.
NIOSH received a technical assistance request in December 2003 to assist with the investigation of a home built above an abandoned coal mine and on a reclaimed surface mine. The residents reported new-onset shortness of breath, lightheadedness, dizziness, poor concentration, and blurry vision while in the basement. Their symptoms resolved within minutes after leaving the basement. Investigators found an oxygen-deficient environment in the basement and crawlspace areas of the home. Carbon monoxide and methane were not detected, which led investigators to suspect that carbon dioxide (CO2) could be displacing oxygen in the basement and crawlspace.
A direct-reading CO2 monitor was used for short-term sampling. Concentrations of CO2 were as high as 9.5% in the home’s crawlspace, 11% in the crawlspace gravel, and 12% inside a floor drain (outside air was 0.035%). CO2 levels in the living areas of the home were greater than 1% (10,000 ppm). Oxygen concentration in the basement was intermittently deficient, with levels measuring as low as 14% in the crawlspace (normal range = 19.5 and 23.5%). Air and soil gas samples analyzed for carbon isotopic composition indicated that the CO2 infiltrating into the house was likely from a carbonate source.
Others have reported similar events in homes built above abandoned coal mines in England, Russia, and the U.S. Preventive measures for mining-related indoor air quality problems include sealing cracks, maintaining positive pressure in relation to the ground, and ventilating subsurface areas in a manner similar to that used for radon mitigation. In affected homes, homeowners, public utility workers, and remediation workers could be overexposed to CO2 and in an oxygen-deficient environment. This dictates efforts to increase public awareness of the potential hazards and to appropriately educate people who may be potentially exposed.
Posted May 30, 2005