NC_OLD170: Mediating Exposure to Environmental Hazards Through Textile Systems
(Multistate Research Project)
Status: Inactive/Terminating
NC_OLD170: Mediating Exposure to Environmental Hazards Through Textile Systems
Duration: 10/01/2002 to 09/30/2007
Administrative Advisor(s):
NIFA Reps:
Non-Technical Summary
Statement of Issues and Justification
Introduction
A variety of human health problems have been attributed to occupational exposure to hazardous environments, including toxic chemicals, especially pesticides; as well as heat/fire; and the damaging ultra violet rays from the sun. Data for pesticides alone exemplify the extent and nature of the effects that can result from such exposure. The Environmental Protection Agency (EPA) estimates that 300,000 farm laborers suffer from pesticide poisonings annually (1). These poisonings can produce both acute and chronic health disorders (2-10). In occupations involving thermal hazards, such as fire fighting and metal smelting, providing protection from external heat sources while allowing for adequate release of body heat remains an ongoing challenge (11-12). In addition, sun exposure accounts for over one million new cases of skin cancer each year in the United States making it the most prevalent form of cancer (13). Despite efforts to find other methods to protect humans from environmental hazards, clothing still remains a key component of most health and safety plans. Thus, in light of new science and technologies, there is cause to re-examine recommendations regarding appropriate clothing to reduce human exposure to the detrimental effects of sunlight, heat/fire and chemicals. Another area of concern is consumer education regarding human health and safety. The proposed project will address the issues that impact human health and safety and lifelong learning as stated in the research priorities of the North Central Regional Association (NCRA). The focus will be on personal protective equipment (PPE) that mitigates the effects of environmental hazards. Importance and Extent of the Problem:
Thousands of workers, engaged in the application and use of pesticides, are vulnerable to chemical exposure. The EPA estimates that in the farm sector alone, some 560,000 sites such as farms, forests, and greenhouses have workers who come in contact with these chemicals during their workday (14, 15). Pesticides are also widely used in other industries, such as lawn care and horticulture, and by homeowners. According to the EPA, 75% of U.S. households use pesticides; annual use in 1997 was about 76 million pounds (16). Moreover, approximately 8,000 commercial establishments handle pesticides during their daily operations. The current NC-170 project (1997-2002) generated scientific knowledge regarding the viability of textile systems for hand and body protection against pesticide chemicals, the effects of use, storage and environmental conditions on product integrity, and the development of a standard method for assessing barrier efficacy of protective materials. The standard method has been approved by the F 23 Committee on Protective Clothing of the American Society for Testing and Materials (ASTM), and was submitted to the International Standards Association (ISO) for review and adoption as a standard. Furthermore, outreach materials were developed and disseminated through cooperative extension programs and websites to encourage better use and care of protective clothing and equipment by various constituencies. However, much work needs to be done to improve PPE performance in relation to human factor criteria such as comfort, and safety; to develop standard performance specifications for screening PPE for specific applications; and to design better educational programs and strategies to assure acceptance of various types of PPE. In occupations where workers are exposed to thermal hazards, a major issue is to maximize protection from flames and radiant heat while minimizing metabolic heat stress (11, 12, 17, 18). Another concern is making sure that the PPE is designed to provide acceptable levels of mobility and range of motion (19, 20). Again, the current NC-170 project provided some data on suitable materials and designs for fire fighter protective jackets and pants. However, field tests suggest some additional design improvements are needed. Also, other elements of the total PPE system, beyond the basic jackets and pants, should be assessed in terms of contributions to thermal protection. Furthermore, data on changes in thermal protection with use, care, and storage are lacking. Impetus for research on UV protective clothing comes from evidence of a steady increase in the incidence of melanoma skin cancer over the past twenty years, at least partially due to lifestyle changes that reflect an emphasis on sunbathing and acquiring a tan. Melanoma is linked particularly to intermittent, high intensity UV exposure during childhood. One or more severe sunburns during youth double the risk of developing melanoma (21). Also, the risk of developing melanoma will increase with further depletion of the ozone layer. Since ozone is an effective UV-absorber in the UV-B region (280-315nm), a subsequent increase in UVB radiation is expected, thus increasing the risks of sunlight exposure in the future (22). The current NC-170 project (1997-2002) initiated research on development and user evaluation of headwear designed for protection from UV radiation, and the development and dissemination of outreach materials through cooperative extension programs and websites to encourage behaviors in support of minimizing exposure to UV radiation. However, there is still a need for additional research in this area. Studies done to date have focused on only one or two aspects of UV protective materials and calculated protection in a variety of ways. A systematic study of the effects of fiber properties, yarn and fabric construction, and various types of dyes along with the potential for a symbiotic relationship between these factors and garment design, needs to be undertaken. Also, no work was found that studied the effect of enzyme processing of textiles on their UV protection characteristics. Since enzyme processing of textiles is projected to increase exponentially in the future due to lower energy requirements and the generation of less environmentally hazardous byproducts, the need for research is apparent. Whatever hazard is being considered, the success of protective clothing is dependent on issues related to garment design. Interactions among anthropometric measures, garment sizing, garment design features, textile properties, garments and equipment, worker acceptance, and cost can affect the performance of protective clothing. Clothing that does not fit well cannot offer protection or safety: clothing that is too tight or binds will affect work performance and may leave areas of the body exposed, clothing that is too loose hampers movement and can catch in equipment. Resolving these complex issues requires prototype development, testing, and redesign in order to find optimum solutions (23-26). Need for Multi-State Cooperative Work:
This multidisciplinary and multifaceted research program requires intense cooperative efforts among the participating researchers/states because each has unique expertise and associated facilities, as well as similar or complementary expertise. The team has the ability to collect different types of data from their states that can be pooled for comprehensive analyses useful for strong national/international programs. For example, researchers at OK, CA, MI, NY and TX have expertise, facilities and equipment to conduct human factors research. NY has state-of-the-art body scanning equipment to produce fit research for both product development and fit assessment. OK has an Environmental Design Laboratory and equipment in support of conducting controlled environmental thermal comfort studies to obtain subjects physiological and perceptual responses to wearing prototype clothing under selected environmental conditions, as well as assessing mobility, dexterity and movement. OK is obtaining equipment to measure the thermal and evaporative resistance of textiles. TX has equipment to characterize the hand property of textiles (82-86). CA and MI have expertise and facilities in support of conducting socio-psychological human factors assessments. For example, CA has a behavioral laboratory with a one-way mirror and video equipment for focus group interviews. Other laboratories have the expertise to characterize textile materials for physical, mechanical, chemical (IL, MD, NY), sensory (TX), and sun protective (CO) properties; as well as target hazards such as chemicals (IL, MD, NY), and UV radiation (CO). These parameters are useful for assessing protection, developing test protocols, standardizing test methods, and performance specifications. IA, MI and NY researchers have expertise and facilities to conduct surveys and field studies that will complement the work of NC-170 researchers under different objectives, and synthesize data useful for developing educational materials and extension training programs. All participating states will develop and disseminate research and/or educational information to various audiences through multiple media. The diverse types of expertise that will be brought to bear on issues outlined in this proposal result from the different specialties of Technical Committee members. Although all are from textiles and clothing programs, the group is interdisciplinary in that it includes social scientists, physical scientists and engineers, and designers. In addition, committee members plan to draw heavily on advice of faculty members from other disciplines at their respective institutions. Those faculty who are expected to have the greatest input are listed in Appendix E as "Other Collaborators." For example, Charles Schwab (IA), Andrew Landers (NY), and Michael Helms (NY) will contribute their expertise on engineering controls for pesticide applications to the Objective 2 study of applicators' understanding of the relation between engineering controls and PPE. Larry Olsen (MI) will provide advice on selection of pesticides for the pesticide protection studies described under Objective 1. Bob Krieger (CA) will be responsible for the evaluation of pesticide monitoring tools, including biomonitoring, that are integral to the CA field study included in Objective 1. Relationship to Current Priorities:
The proposed research will address the NCRAs research priorities related to human health, safety, and well being under Integrated Pest Management (IPM); and Natural Resources and The Environment. Furthermore, it will contribute strategies/ technologies for lifelong learning of individuals/consumers and also identifying factors related to demand and barriers to demand for products improving human well being under the Social Change and Development priority. Benefits to the Solution:
The proposed project will focus on improving the protection and performance of PPE through product development efforts with emphases on human factors such as comfort, fit, and ease of donning and doffing, and expansion to new protective clothing applications. Also, best strategies for product and practice adoption will be developed including information delivery systems that influence the adoption of safe PPE practices. Furthermore, the current work on standard test methods will be expanded to develop performance specifications (which are based on standard methods) for protective clothing that can be used to classify materials. Lack of standard test methods and performance specifications limits ability to compare results across research projects and to provide the best advice, based on solid scientific evidence, to people selecting PPE. These performance specifications can be used by crop protection companies and manufacturers of PPE for pesticide applicators. Furthermore, these specifications may be used as a basis for PPE recommendations included on the pesticide labels. Thus, the objectives proposed herein are expected to benefit agricultural and other workers as well as the general public exposed to environmental hazards, by considering factors such as thermal protection and heat stress, as well as chemical and UV protection. The potential for benefits to stakeholders such as pesticide applicators and fire fighters as well as general consumers is suggested by the number of times participants in the current project have been contacted to provide information about PPE.
Related, Current and Previous Work
Regional Project NC-170, Occupational Safety and Health Through the Use of Protective Clothing (October 1, 1997, through September 30, 2002) focused on the following four objectives:
- Assessing the viability of various textile systems for hand and body protection for selected occupations.
- Evaluation of the effects of environmental exposure, use and storage conditions on the functional integrity of PPE for selected occupational settings.
- Assessing policies, regulations and practices for environmentally sound disposal of PPE.
- Proposing standard methodology for industry-wide consensus standards for chemical protective clothing.
Objectives
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To improve protection and human factor performance of PPE through product development.
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To examine acceptance and barriers to acceptance of PPE products and practices.
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To develop performance specifications for protective clothing materials.
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Methods
Objective 1: To improve protection and human factor performance of PPE through product development.Participating states: CA, CO, IA, MI, NE, NY, OK, TX
Product Development Studies
Developing new materials, new finishes for materials, and prototype garments will constitute the work to be accomplished in the product development studies. TX and CO will cooperate on developing nonwoven materials for UV radiation protection. TX has acquired a state-of-the-art HI technology needleloom which will be used to develop nonwoven substrates from fibers varying in type and linear density. TX will be the first and only facility in the US to house the modern needleloom. HI technology webs have been found to have higher strengths and web cohesiveness compared to conventional needle webs. These webs might offer more penetration resistance to UV radiation. The webs will be tested for their ultraviolet protective factor (UPF) by CO. CO will investigate use of advanced chemical finishing techniques to enhance materials UPF or UV protection characteristics. (UPF indicates how many times longer a person can be in the sun wearing a fabric, compared to not wearing the fabric, before the onset of skin reddening.) The chemical finishing techniques include treatment with fluorescent whitening agents and application of UV absorbers and other additives. UV absorbers possess chemical groups that effectively absorb radiation in the UV region, enabling them to maximize the absorption of UV radiation on textiles. The efficacy of UV absorbers with different functional groups will be studied and their mode of application on fabrics and garments defined. NE will explore mechanical finishing technologies for fabrics, such as sanding and compacting, as methods of modifying the surface structure of non-woven fabrics. Such modifications may decrease the penetration of UV radiation through protective clothing. CO will also investigate the use of environmentally friendly enzymes in finishing and their effect on UV protection. The new non-woven substrates developed by TX will be considered as potential candidates for COs enzymatic treatments. Enzyme processing of textiles necessarily results in changes in tactile properties such as hand, which will be investigated by TX (see Human Factor Studies below). NY will develop prototype garments in a 3-step process. Step 1 will include development of an activities matrix to identify typical activities performed by users from selected occupations. Step 2, the design research stage, will be accomplished with researchers from several states participating in a video conference to generate design ideas to accommodate the activities identified in step 1, with NY developing patterns for the resultant designs. A fit test will be conducted for step 3 as outlined under Human Factor Studies. The garments barrier properties will be assessed through testing conducted by IA and CA (see Protection Studies below). User acceptance of the garments will be evaluated by different states under objective 2 and the results of both evaluation studies will be used to redesign as necessary.
Protection Studies
Protection studies are planned for three hazard categories, UV radiation, chemical and fire/flame. CO will measure UPF values of the fabrics in the MD database, as well as the UPF values of materials being promoted for sun protection. The UPF values will be measured using a Labsphere UV-100F Ultraviolet Transmission Analyzer. The instrument software calculates the average value for the UVB (280-315nm) and UVA (315-400 nm) spectral regions and converts the data to give a UPF rating for the fabrics ultraviolet blocking ability. An advantage of this instrument is that it is not affected by fluorescence in assessing the UV protection offered by optical brightening agent (OBA) treated fabrics, and it can quantify the OBA concentration in fabrics. Two different approaches will be used to assess UV exposure of human subjects. MI and OK will conduct a field experiment using personal dosimetry to quantify UV exposure using spectrophotometric techniques. Participants will be extension personnel or campus pesticide applicators. Dosimeters made of polysulfone film will be used to measure the effectiveness of various clothing systems. Specifically, when dosimeters are placed on body sites under clothing, such as on the head and neck, the effectiveness of garment design features, such as hat brims and collar designs, can be determined. Dosimeters will also be used to compare the effectiveness of garments made from specialized fabrics, purported to have enhanced UV protection, with one and two layers of cotton work clothing. MI and NY will measure the sun protective qualities of headgear using images from the 3D body scanning equipment at NY to assess UV exposure. Commercially available hats, visors, and shirt collars will be worn by subjects of various head sizes, head carriage, and neck angles. Scans will be made of each subject in each headgear treatment and the scans will be analyzed for coverage of the face, ears and neck for various angles of the sun. The information will be used in two ways: 1.) to generate design ideas for prototype headgear (see Product Development Studies), and 2. to develop extension publications and/or web-site information for educating consumers. CA and IA will incorporate two field methods to assess the chemical protection characteristics of the prototype garments developed by NY (see Product Development Studies), while simultaneously assessing users perceptions of the acceptability of the prototypes, as given under objective 2. IA will conduct a deposition study. CA will use biomonitoring to obtain estimates of the average amount of pesticide absorbed through the skin. CA will also conduct two studies to assess the thermal protection characteristics of wildland fire fighter clothing. One study will focus on the thermal hazards associated with oil-based versus water-based silk-screened emblems. This study will utilize University of Albertas thermal mannequin to assess extent of burn injuries under the two different emblem conditions. The second study will examine the effects of UV radiation on the radiant protective performance (RPP) of the Nomex. used for California Department of Forestry and Fire Protection (CDF) PPE. Swatches will be exposed to a xenon arc light in a Weather-Ometer for periods of 20, 40, 60 and 80 hours and then compared with a control swatch to ascertain any changes in RPP values. Human Factor Studies
Human factor studies will be conducted in the areas of fit, hand and thermal comfort. Fit testing of the prototype protective garments will be done at NY using participants of different sizes. The participants will be scanned in the anthropometric position and in various active positions with and without the prototype garments. Both scans will be superimposed in the same file for analysis. Areas of poor fit will be identified and the design will be modified accordingly. The characterization of fabric hand is an important human factor consideration in judging the performance characteristics of a wide variety of fabrics. A new method and instrument to characterize fabric hand were developed by TX, and detail on both the method and apparatus are given under objective 3. TX will evaluate the hand properties of the fabrics in the MD fabric database by using the new hand method and apparatus. Thus, the MD fabric database will be expanded. Similarly, OK will expand the database by assessing the thermal resistance of the same set of fabrics using a sweating guarded hot plate per ASTM F 1868. NE will conduct tests of liquid transport in multilayer fabric systems using Nuclear Magnetic Resonance (NMR) technology (86). Objective 2: To examine user acceptance and barriers to acceptance of PPE products and practices.
Participating states: CA, IA, OK, NY, MI.
Pesticide applicators responses to wearing lined vs. unlined gloves
This study will measure the contamination levels in cotton glove liners worn under chemically-resistant gloves during pesticide handling/application. It will also assess worker comfort and satisfaction with cotton glove liners. Indoor occupational pesticide handlers who work year round in NY and IA will be recruited to wear cotton liners beneath nitrile gloves. The applicators will wear the glove ensemble for 8 hours on five separate days. Wearers will record date, time, pesticides used, application method, spray environment, and any problems encountered. Gloves and liners will be analyzed by gas chromatography for pesticide residues. Wearer attitudes and perceptions in regard to comfort and acceptability will be assessed with a written instrument adapted from an earlier study on glove liners by Branson et al, (44) and through follow-up focus groups. Pesticide handlers understanding of how PPE requirements change with engineering devices for application
Data on the perceptions of pesticide applicators regarding the relationship between PPE and engineering controls will be collected using a survey instrument developed with input from growers, pesticide handlers, educators, and researchers. The instrument will be tested in a pilot study in NY as follows:
- questionnaires will be mailed to members of the New York State Vegetable Grower Association,
- face-to-face interviews will be conducted with attendees at the Empire Farm Days, a three-day farm management and equipment show that attracts 75,000 annually, and
- telephone interviews will be completed by the Computer-Assisted Survey Team, Cornell University, with volunteers recruited from pesticide applicator sessions.
Field testing of the protective garments designed in Objective 1 will be carried out at several sites. Two sets of garments will be tested in a two-stage process. In stage one, basic measurements will be taken of each participant and participants will be given size selection information for the two different designs. Each subject will choose and don a protective garment from each set and a visual record will be made for subsequent fit rating. These images will be made with the subjects in an anthropometric position and in a series of active positions. In stage two, each subject will wear each garment for three hours in the field. The subjects will complete questionnaires to rate ease of donning, fit, comfort, general acceptability, and any problems encountered in the field. Data from the various sites and the two garment styles will be compared to determine whether the new styles provide improvement in fit, comfort, general function, and size selection methods. Recommendations for further design changes will be made based on these data. OBJECTIVE 3. To develop performance specifications for protective clothing materials.
Participating states: IL, MD, and NY
Performance Specifications for Protective Clothing Materials:
The research team will work closely with the ASTM Committee F-23 on Protective Clothing to develop Performance Specifications for Protective Clothing Materials for Pesticide Applicators. MD will coordinate the work with ASTM. In the first two years, researchers at IL, MD and NY will identify the most significant factors that determine barrier efficacy of PPE materials based on laboratory physical and chemical testing and analyses. Meetings will be held with individuals from the pesticide industry, protective apparel industry, and federal groups responsible for the worker protection standards. Information obtained will be used to draft the performance specifications that will be shared with the stakeholders. In year 3, the draft will be revised and field studies will be conducted to validate the lab test results and performance specifications. Researchers will propose these performance specifications to European counterparts and ISO for global acceptance. In year four, the performance specifications will be submitted to ASTM for approval. Information will be disseminated to the users in year five.
Measurement of Progress and Results
Outputs
- New materials, new finishes, new layering systems, and garments for protection from pesticides
- New surface treatments and new layering systems for minimizing thermal hazard impact.
- New materials, new finishes, and new layering systems for protection from UV radiation protection.
- Recommendations for changes in pesticide labels to clarify PPE choices.
- Empirical evidence on wearer acceptance and use of glove liners.
- Standard Performance Specifications for PPE for pesticide applicators <LI>Posting of information obtained from the proposed research and educational experiences on the USDA Regional Research Project NC-170 website <http://txnc170.human.cornell.edu/>. </OL>