J. Morrison, Wisconsin Division of Public Health, Madison, WI.
On July 19, 2005, a tire fire occurred at a 12 acre recycling facility in southeastern Wisconsin. The smoke plume was visible for over 30 miles and readily apparent on satellite imagery. Response involved 106 fire departments, as well as local, state and federal health and environmental agencies. Concerns arose immediately about health impacts associated with the smoke. Communication with nearby residents occurred through door-to-door contact and local media. Voluntary evacuation was implemented to minimize exposure. Nonetheless, many remained near the scene including responders, support staff and community members. Respiratory protection needs for those near the scene posed a number of challenges. Particulate exposure was the primary health concern. Average particulate levels as high as 3,471 µg/m3 were observed near the fire scene and 185 µg/m3 as far as 0.50 miles from the scene. Average particle diameters ranged from 0.029 µm to 1.232 µm. Direct-reading monitoring stations indicated limited toxic gas exposures with maximum values of 50 ppm carbon monoxide, 5 ppm nitric oxide and 0.4 ppm hydrogen sulfide. Volatile organic compound (VOC) levels were variable and generally less than 10 ppm. Levels as high as 11,000 ppm were observed near the fire scene. Benzene, trimethylbenzene and 1,3-butadiene were present in laboratory analyzed samples. Gas and VOC emissions were highest during application of fire suppressant. Plume characteristics varied with the intensity of the fire and climatic conditions. Plume direction changed 270 degrees during the five-day fire and was close to ground level at times. Monitoring data suggests that large areas can be affected by particulate emissions and in some cases by VOCs. Preparations should be made to communicate directly with nearby residents and to address the respiratory protection needs of communities affected by such fires.
M. Van Dyke, J. Martyny, S. Arbuckle, N. Erb, National Jewish Medical and Research Center, Denver, CO.
The increasing prevalence of clandestine methamphetamine drug manufacturing and the chemicals used in this process lead to a great concern regarding chemical exposures to first responders and susceptible third parties. While many of these exposures have been previously documented, there is currently no information on the persistence of the exposures or the physical characteristics of the methamphetamine aerosol. The current study was designed to measure exposures and contamination up to 24 hours after a controlled methamphetamine cook. Measurements included airborne levels of iodine, hydrogen chloride, and volatile organic compounds, as well as, both airborne and surface levels of methamphetamine. The design of the study was intended to simulate the exposures that may be encountered by the inhabitants of a clandestine laboratory during average living conditions such as walking through the house, crawling on the floor, and vacuuming the carpet. In addition, cyclone and cascade impactor samples were collected during all phases of the experiment to measure the particle size distribution of the methamphetamine aerosol. The day after the cooking process, average iodine concentrations ranged from 0.002 ppm to 0.005 ppm depending on the level of activity in the structure. Average hydrogen chloride concentrations ranged from 0.002 ppm to 0.005 ppm and airborne methamphetamine from 70 µg/m3 to 210 µg/m3. Cascade impactor samples indicated that during the cook an average of 79% of the methamphetamine was collected as particles less than 0.1 µm in diameter. This percentage increased to 97% the day after the cooking process. These data suggest that low level exposures to methamphetamine and manufacturing related chemicals continue up to 18 hours after a cooking process. Particle size data indicate that methamphetamine is readily respirable and likely present as a vapor rather than a particulate aerosol.
J. Mustard, P. Hansen, Pacific Environmental, North Vancouver, BC, Canada; G. Wedman, Pacific Environmental, Nanaimo, BC, Canada.
In British Columbia there are an estimated 15,000 to 20,000 illegal marijuana grow operations. The majority of these operations occur in single-family homes that are often sold to unsuspecting buyers. When police terminate the operations, the occupancy permits are withdrawn by the municipalities pending an environmental assessment to ensure the building is safe for occupancy. Environmental problems associated with buildings occupied by grow-ops include fungal contamination due to high humidity, heat and excess use of water, as well as potential chemical contamination from the use of pesticides and fertilizers. Either prior to, or following remediation, a hygienist becomes involved to ensure the building is safe for occupancy. The initial condition of the building may vary significantly and the extent of remediation carried out may not be known to the homeowner or hygienist retained by the owner. Following a visual inspection, which indicates contamination has been remediated, sampling is conducted according to municipal requirements. This may include fungal spores in air (spore trap sampling), pesticide contamination (surface wipes), and fertilizer contamination (surface wipes). The objective of this paper is to compare the residual contamination in former grow-ops where the remediation history is unknown, with properties where a hygienist was involved prior to the clean-up and where the extent of remediation is known. Sampling has been conducted in approximately 70 homes formerly used as marijuana grow operations. Summary results of pesticide, fertilizer, and spore-trap sampling (by genus) will be presented.
C. Marlowe, Camp Dresser & McKee, Scotch Plains, NJ.
Until recently, decisions on water disinfection systems were made solely on the basis of reliability and feasibility. After the Process Safety Management standard and Risk Management Program Rule were promulgated, risk entered into the decision process. Decisions, however, are not often made in a systematic way. Factors that enter into the decision, and perhaps should not, include: the age of the system, the income of the nearby residents (and their access to lawyers), the general personality of the decision maker, and the state in which the disinfection system will be installed. The use of gaseous chlorine, in particular, presents hazards that can remain in control only with an active control system. Many facilities have written programs that document such active control systems and implement those programs faithfully. Some others do not. Of even greater concern are small systems, many of them rather old, that use gaseous chlorine, but are not subject to any control program at all. Although most such small systems are exempt from federal regulations, they still handle an extremely hazardous substance that could negatively affect employee and community health. This paper will document an approach that incorporates the: Water treatment goals, in terms of purity and contact time; Size of the disinfection facility; Capital budget limitations; Operating cost limitations; Floor plan limitations; Chemical shipping cost considerations; Number of employees at facility; Occupants of the surrounding area; Sophistication of facility management; and Applicable regulations.
D. Sterling, F. Serrano, A. Hobson, Saint Louis University, St. Louis, MO.
La Oroya is a town of 35,000 located at 14,000 feet in the Peruvian Andes; an area rich in lead, copper, zinc, silver, and gold. Extraction and smelting of these metals has been the primary economic activity since the 1920s. Several investigations have documented severe environmental contamination. In 1999 the Peruvian Ministry of Health found that 99.1% of children suffered from lead poisoning; with 20% of these children needing urgent care. A 2002 report “La Oroya Cannot Wait” described the levels of ambient contamination of air, soil, and water. The report indicates that over 80% of blood lead levels in children were two and three times greater than the level of concern of 10 µg/dl established by the CDC. The report found that arsenic, cadmium, suspended particles, and sulfur dioxide (SO2) exceeded international acceptable levels and posed serious health risks to the community.
A study to address the following questions was performed in August 2005 in collaboration with investigators from the United States and Peru:
Random sampling of of over 250 residents and their homes was performed on both La Oroya and a control city over a four-day period. This included completion of a questionnaire, basic medical evaluation and blood and urine samples from up to four age ranges within a residence, and environmental samples of drinking water, soil, and handwipes of various surfaces and childrens hands. Cultural, language, and social situations made this a unique collaborative effort with grassroots and faith-based organizations and application of exposure assessment and subject recruitment methods.
W. Colter, Dynamic Ventilation, LLC, Jamestown, NY.
This paper presents a varying speed fan method for general ventilation of hot factories so as to provide control of thermal conditions and general indoor air quality, during all seasons of the year. Roof-mounted propeller fan assemblies are used. The fans are mounted centrally in the building in the horizontal plane on steel beams above the roof. A flat roof is installed above the fan. A horizontal splash-plate diffuser, approximately 18 foot x 18 foot, is installed below the fan-roof opening. The fan speed and direction is controlled by a variable speed drive (VFD). An electronic room temperature controller is used as the primary input to the VFD for fan speed control. An outdoor temperature switch is used to provide input to the VFD for fan rotation direction control. During warm and hot outdoor conditions, the fans operate as standard roof-mounted exhaust fans, at 60 Hz, bringing the coolest air into the building through open doorways and exhausting the hottest air out of the ceiling space. When outdoor temperatures fall to approximately 60 degrees F, the fans are automatically switched into reverse direction. In this direction, the fans supply outdoor air into the hottest areas of the building, being distributed radially and mixing into the ceiling space by the splash-plate diffuser. As outdoor temperatures cool, the fans automatically reduce speed to maintain the setpoint of the room temperature controller. Air goes out the open doorways limiting uncomfortable incoming cold drafts, and negative building pressure is avoided. Because high volume flow rates are required, and because of economies of scale, large fans are used: 12 foot diameter/250,000 CFM/25 HP; 10 foot diameter/200,000 CFM/20 HP. VFD use reduces electrical operating costs.This ventilation design is disclosed in United States Patents US 6,241,604 B1 and US 6,375,563 B1.
Posted May 30, 2006