Development and Field Evaluation of Summer Garments for California Agricultural Workers.

摘要

California's agriculture industry is the largest in the country due to the vast expanse of fertile land and suitable climate. The produce feeds people in all parts of the country and world. Consequently, the industry is also one of the largest employers in the state as hundreds of thousands of workers earn a living from agriculture.;While California's climate allows for a variety of crops to grow and flourish, it also presents challenges or potential hazards to farmworkers. One example is heat stress in summer since they are working outside in the fields for hours in the sun and a temperature exceeding 100 degrees Fahrenheit. This, combined with workers' own heightened metabolic heat production produced in the body from physical exertion, can have deadly outcomes. Heat stress is explained as strain in the body affecting physiological processes occurring when internal body temperature rises above 98.6 degrees Fahrenheit. The internal systems are unable to get rid of the excess heat fast enough. Heat can transfer from the body through conduction, convection, radiation, and evaporation paths. Among these, evaporation is the most important and effective one when the external temperature exceeds body temperature. Convection can also be a significant method when wind or air movement is involved.;Generally speaking, the clothing we wear has a significant impact on our thermal comfort, by insulating our body to some degree. Wearing less or lighter clothing is an option to most people in the summer. However, farmworkers are required to be protected from exposure to pesticides by wearing long pants and long sleeve shirts, which could be another barrier to heat loss. However, clothing design can have an impact on the heat lost from the body and certain design features will allow for greater evaporative cooling and convection, which can more effectively cool the body. This can lead to the development of the optimal garments for California agriculture workers with reduced risk of heat stress.;The purpose of this research was to determine how functional garment design can help to reduce heat stress in farm workers. In order to determine how to reduce heat stress in agricultural workers through clothing, the research was conducted in four parts: material selection and testing, garment design and development, garment laboratory tests on a thermal manikin at Boise State University, and field tests on participants working at the UC Davis Student Farm. The results show that garments with increased ventilation features and highly air permeable fabrics will have higher heat loss compared to standard work wear currently on the market. Subjective feedback from participants in a field test also were consistent with the scientific measurements. By wearing functional garments as mentioned, farmworkers have an easy, effective, and economical way to stay cooler in the summer while working. It is recommended that outdoor workers in California be educated on the clothing design features that can benefit their comfort and productivity by reducing heat stress.