Agriculture, Forestry, and Fishing

Burden

There were 761,700 agricultural workers in the U.S. in 2014, and 528,000 of them were employed as equipment operators, farmworkers and laborers, and crop, nursery and greenhouse workers [BLS 2017]. 82% were male, 42% were foreign born, 45% reported Hispanic ethnicity, and 64% were US citizens [USDA 2017]. Pesticides are used throughout the agricultural industry, and in 2007 a total of 684 million pounds of active ingredients were used in US agriculture [Fishel 2007]. Farm workers are exposed to pesticides during mixing, loading and application tasks and during reentry following application. Skin is the primary route of pesticide exposure, contributing between 81 to 97% of total systemic uptake from these operations [EFSA 2013]. Dermal exposures to pesticides lead to diseases of the skin including both irritant and allergic contact dermatitis. Both acute and chronic pesticide exposures carry health risks [Donham and Thelin 2016].

Acute pesticide exposure illnesses can include abdominal pain, dizziness, headaches, nausea, vomiting as well as skin and eye complications [Hoppin and LePrevost 2017]. Death is rare but still a known outcome. From 1998–2005, there were 3,271 cases of acute pesticide poisoning reported among 10 participating states for an incidence rate of 53.6 out of 100,000 full time agricultural workers [Calvert et al. 2008]. In another analysis, only 13% of applicators and 22% of their spouses with symptoms resulting from high pesticide exposure events sought medical care, suggesting that pesticide poisoning surveillance data may underreport the actual occurrence [Bell et al. 2006].

Need

Data is needed to improve dermal risk assessments of pesticide exposures. Basic research needs to be conducted to measure the dermal uptake rates of pesticides in concentrated and in-use commercial formulations at exposure levels that are typical of agricultural applications. Quantitative pesticide exposure assessments among agricultural workers and their families will provide this additional data.

NIOSH and NIOSH-funded researchers are uniquely suited to carry on this work. Past and current laboratory and field work has been done on worker pesticide exposure. NIOSH is currently leading surveillance on pesticide exposure in the U.S. NIOSH-funded Agricultural Safety and Health Centers have completed multiple projects on various aspects of pesticide exposure to workers. Recently completed studies include neuromotor and work injury risk after pesticide exposure, discovering improved methods to assess pesticide exposure, reducing pyrethroid pesticide exposures in dairy workers, and pesticide safety in tree fruit growers.

Burden

Diseases shared by humans and animals are likely to affect agricultural workers and their families. Examples of pathogens causing zoonotic diseases include Escherichia coli O157:H7, Salmonella, and Cryptosporidium. Daly and Hill [2016] found Cryptosporidiosis and E. coli infection as two especially harmful diseases from farm exposure in a rural setting, whose burden may be larger than previously considered. Little information is available describing specific risk factors on the farm for developing a zoonotic disease and how frequently agricultural workers and their families get sick from food animals. Surveillance of zoonotic disease is critiqued as being challenging and progressing slowly [GAO 2010]. Most new or emerging infectious diseases (3 out 4) are zoonotic, transmitted between animals and humans [CDC 2016]. Zoonotic avian viral strains, such as the highly pathogenic H5N1 or H7N7 virus strains, can cause an influenza pandemic should they become communicable between people [NIOSH 2008].

Need

Currently, information is lacking on how frequently these infections occur among agricultural workers, what the specific risk factors are for becoming ill from a zoonotic disease, and what preventive measures may be most effective. NIOSH is frequently called on to help develop guidance on protecting these workers during outbreaks. Information gained from this research is critical in aiding the development of guidance. Research on surveillance (i.e. Cryptosporidiosis and Escherichia coli listed above), transmission, risk assessment, infectious disease networks, prevention, and control measures for U.S. workers is lacking and should be addressed. While it’s clear that agricultural exposures are linked to infectious disease transmission, surveillance data is known to be meager [Klumb et al. 2013]. NIOSH is funding Agriculture Safety and Health Centers around the country, and many of them have experience and facilities to do work on zoonotic diseases. By understanding how to minimize the risk of zoonotic disease transmission, public health professionals can safeguard worker and community health.