Farmworker Acceptability of Backpack Hydration Systems

Abstract

Objective:

To improve water access while working and contribute to fewer heat-related illnesses (HRI) backpack hydration systems were provided to over 200 farmworkers to use during the 2022 growing season. Acceptability of the water intake intervention was assessed among farmworkers in eastern North Carolina, USA.

Methods:

With a pre-established community-university partnership, the acceptability of the intervention was assessed using a cross-sectional survey. The backpack brand selected included a 3-liter water bladder and attached drinking hose. Data analysis included descriptive and correlation statistics.

Results:

Among 47 male, migrant farmworkers, most (90%) reported the hydration backpack to be acceptable or completely acceptable to workplace fluid intake. Most (53%) reported using the backpack some of the time, compared to 28% who used it often. The participants reported an average of 4.8 (SD 2.2) liters of water intake from the backpack on a typical workday. Most reported the backpack improved the quantity and frequency of their water consumption.

Conclusion:

This study was an important first step in implementation of hydration backpack systems as an HRI-preventative intervention among farmworkers. Future interventional studies could assess the efficacy of the backpacks on health outcomes, including incidence of dehydration and symptoms of HRI.

Introduction

Occupational heat-related illness (HRI) death is highly preventable [1], yet dozens of workers die every year from environmental heat exposure [2]. Strenuous work coupled with long hours in the summer, especially in hot and humid regions, can result in heat stress and heat strain which could lead to HRIs [3]. The Occupational Safety and Health Administration (OSHA) provides three vital strategies to protect workers from HRI with its “Water.Rest.Shade.” campaign [4]. These strategies include adequate water intake, periodic rest from work, and breaks in shaded areas. Many sampled farmworkers in the United States are dehydrated after a worked shift [5–7] and report barriers to water intake to be the poor quality of the water [8–11], long distances to the water [8,9,12], short or no breaks [8,13], and no toilet facilities [11,12] or long distances to toilet facilities [8,10].

Common fluid intake practices of farmworkers in North Carolina (NC) [10] and in the US [14] are drinking water from disposable paper cups or water bottles, filled from water coolers. The use of backpack hydration systems among farmworkers could improve workplace water access due to its portable design; therefore, could improve their hydration status and prevent HRI. A typical commercially available backpack hydration system consists of an outer protective backpack, inner water bladder that holds 2–3 liters of water, with a connected flexible tube and mouthpiece. Many refer to backpack hydration systems by a brand name (CamelBak^®). Backpack hydration systems have been used by military personnel for decades and are still commonly used, citing an operational advantage of portable and hands-free hydration [15–17]. Research among military personnel suggest the backpacks protect against dehydration over a 19-killimeter march [17] and over 5 weeks of training in a hot environment [18].

Although limited by small sample sizes, several research studies support backpack hydration system use among other occupational groups and those exercising. With a sample of 8 male firefighters, use of the backpacks protected from hypohydration, and contributed to alleviating heat strain [19]. Bishop et al. [20] found the backpacks protected against dehydration among 10 participants wearing encapsulating coveralls compared to only drinking during rest periods, in simulated moderate intensity industrial work in a moderately hot environment. Compared to water bottle use during an 18-kilometer hike, 14 hikers using a backpack hydration system drank twice as much water, maintained hydration status, and completed the hike in a shorter time [21]. Trained kayakers drinking via a backpack hydration system were able prevent severe dehydration, maintain average core body temperature at 38.5°C and high performance, despite racing in a hot and humid environment [22].

To our knowledge, only one study [23] describes the provision of backpack hydration systems to agricultural workers. Researchers provided backpack hydration systems and other OSHA Water.Rest.Shade interventions to sugarcane workers in El Salvador. Post-intervention, participants reported fewer HRI symptoms, individual daily production increased, and water consumption increased by 25% (from 5.1 to 6.3 liters, on average). During focus group discussions, the workers reported they “adapted well” to the backpacks, which improved their access to cool and clean water.

The purpose of our study was to assess acceptability of a backpack hydration system intervention for water intake among farmworkers in eastern North Carolina, USA. Before resources are dedicated to test the potential health and other benefits from using the backpacks, it would be prudent to first determine the farmworkers’ acceptability of the intervention. Healthcare interventions found to be acceptable are more likely to be translated to occupational practice [24].

Methods

In 2022, an acceptability study was conducted by a community-university partnership. The partnership included staff at one federally qualified health center (FQHC) and university faculty, established in 2018. The FQHC serves a six-county area in eastern NC with approximately 2,300 migrant and seasonal farmworkers working during peak harvest [25]. Using a cross-sectional survey, we measured farmworker acceptability of the backpack hydration system and water intake behaviors. The research team was composed of three FQHC staff and the principal investigator (PI). The staff contributed their expertise of the cultural and workplace norms, as they had previous work experience as farmworkers and established relationships with many farmers and farmworkers in the area. The study was certified exempt from the University and Medical Center Institutional Review Board (UMCIRB) as only surveys were included, and no identifying information was collected.

A prior research study [6] completed by members of the community-university partnership found distance to stored water coolers while working to be a major water intake barrier to eastern NC farmworkers. The partners agreed a backpack hydration system intervention could be an appropriate solution. In response, staff at the FQHC purchased and disseminated the backpacks to at least 200 farmworkers at the start of the 2022 growing season (spring months), at no cost to the workers. The farmworkers lived in the FQHC catchment area.

The backpack brand provided to participants was 17” tall and 7” wide and made of sturdy nylon. Inside the backpack was a bladder that could hold up to 3 liters of water, was BPA-free and food-grade, with connected flexible tube and mouthpiece [26]. See Figure 1. The system cost approximately $20. Prior to receiving the backpack by Stealth Angel Survival©, the farmworkers were educated on how to use and disinfect it and were advised to still have their traditional workplace water source as a backup hydration option. The NC occupational standards on field sanitation [27] stipulate that drinking water must be provided by single service cups or dispensed by a fountain; however, the backpack hydration systems did not violate this standard because the farmworkers did not share the backpacks [A. Guzman, personal communication, April 12, 2023].

Figure 1.

Backpack hydration system by Stealth Angel Survival©

Survey Description

The cross-sectional survey contained 15 questions on demographics, water intake practices, and acceptability of the backpack hydration system. Our survey was adapted from previous farmworker HRI studies [6,13,28,29]. Questions on acceptability were modeled after the Theoretical Framework of Acceptability (TFA) [24,30]. The TFA was developed to determine the acceptability, or appropriateness, of healthcare interventions by those that receive or administer the intervention. The framework includes seven component constructs: affective attitude, burden, ethicality, intervention coherence, opportunity costs, perceived effectiveness, and self-efficacy (see Figure 2 for definitions and descriptions). For this study, specific questions on ethicality and intervention coherence were not included as the research team understood that 1) most of the sample would include Latino farmworkers with strong work values [25,31], 2) work interference was already included in the survey, and 3) all participants received the same training on how to use the backpack. The survey questions were developed in English, translated to Spanish, and translated back to English for comparison [32], completed by two of the staff members of the research team.

Figure 2.

Theoretical Framework of Acceptability (TFA) [24]

Data Collection

The PI and FQHC staff collaborated in the recruitment and retention of Latino farmworkers. A convenience sample of the 200 farmworkers was planned, with a goal of 40 to 60 participants [33]. Data collection was to continue until sample size was met. The FQHC staff traveled to farmworker camps and recruited participants in person, using an informational flyer. Farmworker or migrant camps are farmworker dwellings that can include cinder-block barracks, houses, and mobile homes, clustered in one area. Farmworkers, at least 18-years old, English or Spanish speaking, male or female, that were provided with backpack hydration system from the FQHC in 2022 growing season were recruited for the study. All were provided a consent paragraph describing the exempt study. Of the 47 farmworkers that were approached and met the inclusion criteria all agreed to participate.

Survey data collection occurred between late September and early October 2022, about seven months after the farmworkers received the backpack hydration system so farmworkers could develop routines and opinions regarding the systems. The FQHC staff read the survey aloud and recorded responses on paper or gave the survey to the participants to read and complete, as preferred. The survey took about 15 minutes to complete per farmworker. After, participants were offered a $10 gift card.

The survey data were transferred to an encrypted university protected computer for cleaning and coding. Data analysis was conducted using SPSS (version 27.0; SPSS Inc. Chicago, IL). Pairwise exclusion was used for missing data. Descriptive analysis provided frequencies, means, and standard deviations (SD). Appropriate correlation statistics (Spearman’s rank) were used to examine the associations between acceptability and demographic data.

Results

There were 47 male farmworkers from five different farmworker camps who participated in the study. The cohort average age was 38-years (SD 9.5), ranging from 18 to 53-years. Of the participants, 27% had graduated from high school; the remainder of the sample had at least some middle or high school education. All participants reported being paid by the hour, not by the pound or piece of crop produced, known as piece-rate pay [32]. Of the farmworkers, 45 reported an average of 49 hours (SD 8.5) of work per week (range 30–66), while two did not respond. Most (83%) had access to a toilet within a 3-minute walk from their worksite, while the remainder had a 3-minute walk or greater. All the participants identified as Latino and migrant, working under the agricultural guest worker visa (H-2A) program, a federal and state-run program that helps farmers fill agricultural jobs [34].

About half of the participants (53%) reported using the backpack hydration system some of the time, compared to 28% who used it often (see Table 1). They reported an average of 4.8 (SD 2.2) liters of water intake from the backpack on a typical workday, most (87%) drinking water at least every 15 minutes. Of the participants, 74% agreed or strongly agreed that by using the backpack while working they drank more water (quantity), and 79% agreed or strongly agreed they drank more often (frequency). Almost all (89%) felt confident or very confident about using the backpack, and 92% reported the backpack took little to no effort to use. Most (83%) agreed or strongly agreed the backpack was comfortable to wear, while 87% reported the backpack did not interfere with work. Overall, most (90%) reported the backpack to be acceptable or completely acceptable (Table 1).

Table 1.

Participant backpack use and acceptability (n = 47)

Survey question	f (%)
Backpack Usea
Never	0 (0)
Rarely	5 (10.6)
Sometimes	25 (53.2)
Often	13 (27.7)
Always	3(6.4)
Drank every 15 minutes while wearing backpack
Yes	41 (87.2)
No	6 (12.8)
Drank more water while wearing backpacka
Strongly disagree	3 (6.4)
Disagree	5 (10.6)
No opinion	3 (6.4)
Agree	5 (10.6)
Strongly agree	30 (63.8)
Drank water more often while wearing backpack
Strongly disagree	2 (4.3)
Disagree	4 (8.5)
No opinion	4 (8.5)
Agree	7 (14.9)
Strongly agree	30 (63.8)
Effort it took to use the backpack
No effort at all	31 (66)
A little effort	12 (25.5)
No opinion	3 (6.4
A lot of effort	0 (0)
Huge effort	1 (2.1)
Confident on using backpack
Not very confident	0 (0)
Unconfident	0 (0)
No opinion	5 (10.6)
Confident	2 (4.3)
Very confident	40 (85.1)
Backpack interfered with work
Strongly disagree	9 (19.1)
Disagree	25 (53.2)
No opinion	7 (14.9)
Agree	1 (2.1)
Strongly agree	5 (10.6)
Backpack was comfortablea
Strongly disagree	0 (0)
Disagree	3 (6.4)
No opinion	4 (8.5)
Agree	6 (12.8)
Strongly agree	33 (70.2)
Overall acceptability of the backpacka
Completely unacceptable	2 (4.3)
Unacceptable	0 (0)
No opinion	2 (4.3)
Acceptable	15 (31.9)
Completely acceptable	27 (57.4)

^an = 46

There was a moderate, positive correlation between backpack use while working and overall acceptability (r = .422, n = 46, p = .004), with more use associated with higher acceptability. Lower interference with work scores was also associated with higher overall acceptability (r = −.387, n = 46, p = .008). There was no correlation between age (r = −.070, p = .645), level of education (r = −.051, p = .737), hours worked per week (r = −.103, p = .505), and distance to toilet (r = .245, p = .100) with overall acceptability.

Discussion

To our knowledge, this was the first study to document backpack hydration system use among farmworkers in the United States. The study results suggest the backpacks were a highly acceptable intervention for drinking water while working to a cohort of North Carolina farmworkers. Given the increasing numbers of H-2A visa workers in the US [35] and that NC is a leading state for H-2A worker employment [36], it is not surprising that we recruited a sample of 100% H-2A workers. It is worth noting that H-2A workers have been recognized to have increased vulnerabilities in the workplace compared to other working groups. These vulnerabilities include full control of their housing and transportation by their employer [35], longer working hours [37], and employer intimidation over their temporary work status with the possibility of not being rehired the following season [35,38]. Given this occupational vulnerability, we view the discussion of these results in a positive light for future work with H-2A workers.

Use of the backpack hydration system shows promise to significantly increase US farmworker water consumption. Farmworkers in El Salvador increased water consumption by 25% with Water.Rest.Shade interventions, including the backpack hydration system [23]. The farmworkers in our study reported an average of 4.8 liters of water intake while wearing the backpacks. A cohort of 28 male, H-2A farmworkers from the same region of NC, in another study [6], reported 2.5 liters of water intake per day, whose primary source of drinking water was water coolers stored at the end of crop rows. In this study, participant self-reported data suggests increased quantity and frequency of water consumption; however, we did not assess the specific quantity of participant water intake pre-intervention. Our team is planning a future backpack study with more detailed measures of water and other fluid intake behaviors.

Most of our participants found the backpack to be comfortable to wear while working. The backpack brand provided had a 3-liter water capacity and could weigh up to 4kg (8.8lb) when full. In a study with 13 trail runners, a 3-liter backpack was perceived to be heavier, hotter, and more humid than a 600ml hydration bag worn on the waist or a 600ml bladder-capacity backpack [39]. Despite this, none of the hydration systems affected participant heart rate or the spatio-temporal variables of running. Waist bags or smaller capacity backpacks might not be acceptable to farmworkers, as they drink 2–6 liters on average in a worked shift [6,23,40]; therefore, these would need to be refilled several times a shift. Lower back pain is common among US farmworkers [41], including NC farmworkers [42], which could be exacerbated by the weight of a backpack. When compared to waist bags, the weight of the backpack hydration system can be centered and spread across the entire back. Further studies could assess musculoskeletal pain and productivity impacts from the hydration system, as well as if the backpack will significantly block heat dissipation, increasing risk for HRI.

Backpack hydration systems are intended to be used for multiple years; therefore, the maintenance and longevity of the backpack intervention over several growing seasons should be considered. For example, it will be necessary to evaluate if farmworkers will have the time to maintain the backpack over the lifetime of the product, including the recommended monthly deep cleanings of the backpack bladder and tubing, to reduce incidence of waterborne infection. Common cleaning methodologies include bleach, baking soda, cleaning tablets [16], and specialized cleaning brushes. Among those exercising outdoors, Brainard et al [43] did not identify any significant differences in microbial colonization between water samples from 67 backpack hydration bladders and water bottles. Future studies could illuminate if the backpacks should be maintained by the individual, employer, or outside agency.

Finding the intervention acceptable by the recipient of the intervention is an important first step in implementation of backpack hydration systems as an HRI-preventative intervention. Future studies could assess the perspectives of the people delivering the intervention. In our study the deliverers were staff at a FQHC with a farmworker health program. Other key stakeholders for farmworkers include farmers/employers/crew leaders, Cooperate Extension, and farmworker-serving organizations [44]. Implementation frameworks like Glasgow’s RE-AIM [45] could be used to determine which groups are willing to adopt and initiate the intervention in other areas of NC and beyond.

Due to the urgency of climate change as one of the greatest threats to global public health in the 21^st century [46], future interventional studies could assess the efficacy of the backpacks on incidence of dehydration and symptoms of HRI among farmworkers. There is a need for high-quality scholarship that investigates health interventions for climate change adaptation, particularly in rural spaces. Of 49 studies included in a systematic review on climate change health interventions in rural USA, only 34 unique interventions were identified, including only 2 interventions specific to extreme heat [47].

The backpacks could be an important tool for those writing a heat illness prevention plan, like that required in California Division of Occupational Safety and Health (Cal-OSHA) heat illness prevention standard [48]. California is one of few states in the nation with occupational heat standards. The standard requires employers to provide employees with HRI training, provision of fresh water, shaded rest-breaks, and for employers to develop and implement a heat illness prevention plan. The plan must include the specific procedures for the provision of water to employees. With further research on backpack hydration system use among workers, researchers and healthcare professionals could provide specific recommendations to employers and occupational safety and health groups. As of October 2021, OSHA initiated the rulemaking process to develop a federal heat-specific workplace standard [49], which could include similar workplace requirements like those in place in California.

The strength of this study was our collaboration with a local FQHC allowing for the collection of feasibility data, which potentially allows for the strengthening of a future intervention study protocol. The community and university team were innovative by transferring a current occupational hydration practice to another occupational group. Limitations include participant self-report and a convenience sample of male H-2A farmworkers from one geographic region.

Conclusion

Backpack hydration systems have been found to protect workers from dehydration, reduced heat strain, and are a common tool for water intake by members of several HRI-vulnerable occupational and recreation groups. Backpack hydration systems could be an effective adaptation tool for workers in the era of climate change.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author, [EM], upon reasonable request.