AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
A Comparison of Respirable Welding Fume Aerosol Exposure Reduction by Low-cost and Commercial Local Exhaust Ventilations
JUN WANG, Heng Wang, Marcio Bezerra, University of Oklahoma
Abstract Number: 68 Working Group: Control and Mitigation Technology
Abstract Most welders experience fume exposure which leads to serious adverse health effects, due to the presence of particulate toxic metals and gaseous pollutants in the welding fume. The high concentration of welding fume aerosols existing in the welder’s breathing zone created a challenge to the conventional general exhaust ventilation. In addition, most welding activities occur in poorly to none ventilated areas. Local exhaust ventilation (LEV) is an emission point fume removal device to control the occupational exposures to airborne toxins. The portable nature of LEV made it a desirable device to reduce welding fume exposure. However, the cost of commercially available LEV is still high ($2,000~$10,000 per workstation) and thus limiting its application. Meanwhile, low-cost LEV can be made through retrofitting inexpensive shop vacuum which is commonly seen in small businesses. The study aimed to evaluate the fume aerosol removal performance of a low-cost LEV and a commercial LEV. A welder wore a cyclonic respirable particulate sampler while performing gas metal arc welding on stainless steel metal plates. The ventilation rates of both LEVs were examined using a hot-wire anemometer. The amount of fume collected on the filters were gravimetrically determined, while the carcinogen content such as hexavalent chromium was digested and analyzed by an ion chromatograph. In additional to the personal breathing zone sampling, real-time particle concentration and size distribution measurement were made with several GRIMM aerosol spectrometers located next to the welding area. The results showed low-cost LEV in the circulating mode was not as effective as the commercial LEV. The low-cost LEV in the exhaust mode can perform at the same level of commercial LEV as the welder’s exposure was reduced to 90% of the control non-ventilated condition. However, certain measures should be taken when modifying shop vacuum to reduce risks of flammability and penetration of nano-sized fume aerosols.