Increasing the number of poststerilization purge cycles is a simple approach to eliminating extremely high exposure during unloading. Improvements to ventilation, particularly in the aeration area and warehouse, were also effective in minimizing worker exposures. Use of effective respirator is recommended until the EO exposure levels, averaging 3.41 ppm after the controls, fall below the permissible exposure limit.

Heating, ventilating, and air-conditioning (HVAC) systems ensure indoor air quality and provide a comfortable environment. However, the conventional HVAC systems only provide indoor ventilation and adjust temperature and humidity. This work removes indoor volatile organic compounds (VOCs) using a feasible and novel air-cleaning for an HVAC system, to remove indoor VOCs. An activated carbon-fiber (ACF) filter calcined with copper oxide (CuO) catalyst, called a CuO/ACF catalyst filter, was the developed kit. Formaldehyde, a major VOC, was chosen as the target pollutant. Experiments were performed to confirm the filtration ability of the CuO/ACF catalyst filter in removing formaldehyde in a stainless-steel chamber equipped with a simplified HVAC system. Total air exchange rate (ACH) was controlled at 0.5 and 1.0 h À1 , the fresh ACH was 0.15 and 0.30 h À1 , and relative humidity (RH) was set at 30 and 70%. A first-order decay of formaldehyde existed in the controlled chamber when the two pretreated CuO/ACF catalyst filters were employed. Experimental results demonstrate that the CuO/ACF catalyst filters removed formaldehyde effectively. The decay constant was 0.425 and 0.618 h À1 for 0.5 and 2.0 ppm formaldehyde, respectively. Moreover, the formaldehyde decay rate increased as total ACH, fresh ACH, RH, and the Cu(NO 3 ) 2 concentration for calcination of CuO/ACF catalyst filter increased.

The higher urinary 2,5-DCP concentration in exposed (105.38 μg/L) than non-exposed (1.08 μg/L) workers suggests that 1,4-DCB exposure may increase the 2,5-DCP concentration in urine. Moreover, exposure to 1,4-DCB may also increase WBC count and ALT activity, and PPE may protect workers from 1,4-DCB exposure.

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This study used data obtained from the Taiwan Environmental Protection Administration to measure the dioxin exposure and the body burden for residents living in the vicinity of 19 municipal waste incinerators (MWIs). A survey was conducted in 1999-2003 for the residents. Approximately 16 ambient air samples and a 60-ml blood samples of 84 to 92 residents aged 18-65 yr were collected randomly in four zones (A, B, C, D) for each MWI site based on the atmospheric dispersion model (ADM). Zone A was defined with the highest pollution level, followed by zones B and C, and zone D (background level). Congeners of 17 polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were determined for each sample. We summarized the PCDD/Fs levels in air samples and serum specimens by zone for these 19 sites. The mean ambient levels of PCDD/Fs fitted the ADM, the highest from zone A and the lowest from zone D (2.74 vs. 0.13 pg I-TEQ/Nm3). However, the mean serum concentration in zones A was not distinct from that in zones D (18.7 vs. 19.0 pg WHO-TEQ/g lipid). The age-specific average serum concentration increased from 13.27 pg WHO-TEQ/g in 18- to 25-yr-old subjects to 23.46 pg WHO-TEQ/g lipid in 56- to 65-yr-old subjects. In conclusion, the serum PCDD/Fs levels among residents did not adhere to the dispersion model for incineration emissions. The dose-response of serum PCDD/Fs by age suggests that the body burden of the chemicals is mainly associated with other sources instead of with inhalation.

The purpose of this study was to inactivate indoor bioaerosols using carbon nanotube corona discharge plasma technology. Escherichia coli, Bacillus subtilis, and l virus bioaerosols were generated using a Collison nebulizer. The effect of various factors, including the flow rate (30, 60, and 90 lpm) and the operating voltages (À1.5, À3.0, À4.5, À6.0, and À7.5 kV), on bioaerosol reduction was examined. The results indicated that the corona discharge using the carbon nanotube electrodes decreased the threshold voltage of plasma. The inactivation efficiencies of E. coli bioaerosols using the carbon nanotube corona discharge system at discharge voltages of À1.5, À3.0, À4.5, À6.0, and À7.5 kV were 57, 61, 71, 93, and 97%, respectively. The corona discharge system using carbon nanotube electrodes had higher bioaerosol inactivation efficiency than the corona discharge system using stainless steel electrodes. The results further demonstrated that the inactivation efficiency decreased with an increasing flow rate. The inactivation efficiencies of E. coli, B. subtilis, and l virus bioaerosols using carbon nanotube corona discharge plasma were 93, 88, and 81%, respectively.

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