TY - JOUR
AU1 - Sonia, Grimbuhler,
AU2 - Jean-François, Viel,
AB - Abstract The proper use of personal protective equipment (PPE) plays an important role in reducing exposure to pesticides in vineyard farming activities, including re-entry tasks. However, discomfort from clothing systems may increase the physiological burden on workers. We compared the physiological burdens of vineyard workers wearing three different types of PPE during canopy management in field humid conditions while accounting for occupational, climatic, and geographical environments. The study was conducted in the Bordeaux vineyards of southern France during June 2012. A total of 42 workers from seven vineyards consented to field observations. The following PPE garments were randomly allocated: HF Estufa polyamide (Brisa®), Tyvek® Classic Plus, and Tychem® C Standard. Participant sociodemographic characteristics were collected using a structured questionnaire. Skin temperature and heart rate were monitored continuously using portable devices. Multivariate multilevel linear regression models were performed to account for the hierarchical structure of data. No significant difference was found for mean skin temperature during work. Regardless of the cardiac strain parameter considered, the Tyvek® Classic Plus garment produced the poorest results (P ≤ 0.03). Under the very humid conditions encountered during the field study, the thinness and breathability of the Tyvek® Classic Plus garment resulted in undergarment humidity, imposing additional physiological burden on vineyard workers. These results confirm that the idea of using generic coveralls in any farming activity is unsuitable. Compromises should be created between physiological costs and protection, depending on the agricultural task performed, the crop grown, and the environmental conditions encountered. cardiac strains, personal protection equipment, re-entry tasks, vineyards Introduction Grapes are one of the most demanding crops with respect to plant protection needs. In France, operators applied pesticides in vineyards an average of 19.0 times in 2013 to control various pests and diseases (Ambiaud 2015). Mixing, spraying, and cleaning the spraying equipment (activities conducted by operators) are not the only tasks that potentially lead to pesticide exposure. Indeed, workers enter vineyards after pesticide spraying episodes, to prune (remove plant parts to control the size and form of the grapevine), train (arrange the parts of the grapevine on the trellis to develop a structure that optimizes the interception of sunlight), and manage the canopy (modify the position or amount of leaves, shoots, and grapes to achieve desired arrangement). These re-entry tasks entail physical contact with branches, leaves, and grapes, thus raising the issue of contamination by some active ingredients several days after spraying at levels that could exceed those measured in applicators (Coronado et al., 2004; Baldi et al., 2014). There are three pathways by which pesticides can enter the body: inhalation, oral uptake, and dermal absorption. It is well established that skin absorption is the most common route of pesticide exposure under typical working conditions in an agricultural field; respiratory entry appears to be more limited, likely due to low vapor pressures of many pesticides (Macfarlane et al., 2013). Consequently, the proper use of personal protective equipment (PPE) plays an important role in vineyard farming activities to minimize dermal exposure to pesticides (Thouvenin et al., 2017). Despite the hazard associated with pesticide exposure, however, compliance with PPE among the majority of occupational pesticide users appears to be poor (Perry et al., 2002; Macfarlane et al., 2013). Regulation (EU) 2016/425 of the European Parliament and of the Council of 9 March 2016 is the basis of the European laws related to PPE. However, most European Union member states have no specific agricultural standard for PPE; the same protection standards apply to the chemical industry and to agriculture (Machera et al., 2009; Thouvenin et al., 2017). Before 2016, the exposure models used for pesticide risk assessment resulted in different risk mitigation requirements according to whether the individual was an operator or worker. Exposure models for workers were less stringent and PPE recommendations were not systematic. All applications received by regulatory authorities from 1 January 2016 onward must reflect the new guidance from the European Food Standards Authority (EFSA) on the assessment of operator, worker, resident, and bystander exposure (EFSA, 2014). Among other points, this guidance document clearly states that, “In the case of professional operators and workers, it may be determined that it is necessary to reduce exposure effectively through the use of personal protective equipment”. Discomfort from a clothing system may lead to premature worker fatigue and physiological burdens. Heat stress is a well-documented concern among vineyard workers wearing PPE because several field conditions combine to increase the occurrence of heat stress: high temperature, high humidity, direct sun, and heavy workloads. Numerous precautions are, therefore, recommended to employers to prevent heat stress (e.g. schedule heavy work and tasks requiring PPE for the cooler hours of the day). Surprisingly, although a heavy dynamic workload leads to high cardiac strain, little is known about this physiological cost in vineyard farming activities. The reason may be that this cardiac stress is not obvious upon visual inspection and cannot be assessed through simple sensor monitoring. Worker safety compliance could be expected to increase based on the comfort of the clothing system being worn. To help manufacturers in developing new PPE to reduce job-related discomforts, there is a need for field performance assessment, particularly in humid conditions, that could lead to an increased workload and the re-suspension of residues (and to secondary exposure during re-entry tasks despite regulatory re-entry time). Anticipating the release of EFSA guidance, we thought it was relevant to compare the physiological burdens among pesticide workers of two broadly used EU-certified Category III coveralls (efficacy of which had been assessed to obtain PPE certification) and one polyamide non–EU-certified coverall. If the polyamide-protective clothing leads to lower physiological costs, it would be worth assessing its efficacy; it was anticipated that better safety compliance would be achieved as the usual working coveralls are accepted more readily than EU-certified Category III coveralls (Thouvenin et al., 2017). The aim of this study was therefore to compare, in field humid conditions, the physiological burdens of vineyard workers wearing three different types of PPE during canopy management. Methods Study area The study occurred during the 2012 pesticide treatment season (19 June to 27 June) in the Bordeaux vineyards of southern France. Managers from seven vineyards located in five different vine-growing regions (Sauternes, Entre-deux-Mers, Medoc, Graves, and Blayais) consented to field observations. The vine-training system was the Guyot cane-pruned system. The cane buds grow into shoots that produce the yield in the following season. The spur buds produce shoots that can be used as canes the following year. In single Guyot, only one spur and one cane are left at winter pruning, whereas in double Guyot, two spurs and two canes are retained. The vineyards had an average crop height of 1.66 m. The average planting distance was 1.97 m between rows and 1.03 m within rows (Table 1). Table 1. Vine-growing farm characteristics and general conditions of the vine-lifting task. Estate A Estate B Estate C Estate D Estate E Estate F Estate G Vine-growing farm  Vine-growing area Sauternes Entre-deux-Mers Entre-deux-Mers Medoc Graves Blayais Blayais  Inter-row spacing (cm) 150 160 250 160 250 210 200  Intra-row spacing (cm) 100 100 100 100 120 100 100  Trellis height (cm) 140 160 210 150 180 150 170 Wire-lifting task  Start time (hh:mm) 07:32 07:27 08:49 08:06 08:22 07:03 07:56  Duration (mn) 71 87 98 88 120 107 108  Dry-bulb temperature (°C) 19.0 22.8 24.5 18.1 21.4 18.7 24.4  Relative humidity (%) 81 77 70 70 83 91 71 Estate A Estate B Estate C Estate D Estate E Estate F Estate G Vine-growing farm  Vine-growing area Sauternes Entre-deux-Mers Entre-deux-Mers Medoc Graves Blayais Blayais  Inter-row spacing (cm) 150 160 250 160 250 210 200  Intra-row spacing (cm) 100 100 100 100 120 100 100  Trellis height (cm) 140 160 210 150 180 150 170 Wire-lifting task  Start time (hh:mm) 07:32 07:27 08:49 08:06 08:22 07:03 07:56  Duration (mn) 71 87 98 88 120 107 108  Dry-bulb temperature (°C) 19.0 22.8 24.5 18.1 21.4 18.7 24.4  Relative humidity (%) 81 77 70 70 83 91 71 View Large Table 1. Vine-growing farm characteristics and general conditions of the vine-lifting task. Estate A Estate B Estate C Estate D Estate E Estate F Estate G Vine-growing farm  Vine-growing area Sauternes Entre-deux-Mers Entre-deux-Mers Medoc Graves Blayais Blayais  Inter-row spacing (cm) 150 160 250 160 250 210 200  Intra-row spacing (cm) 100 100 100 100 120 100 100  Trellis height (cm) 140 160 210 150 180 150 170 Wire-lifting task  Start time (hh:mm) 07:32 07:27 08:49 08:06 08:22 07:03 07:56  Duration (mn) 71 87 98 88 120 107 108  Dry-bulb temperature (°C) 19.0 22.8 24.5 18.1 21.4 18.7 24.4  Relative humidity (%) 81 77 70 70 83 91 71 Estate A Estate B Estate C Estate D Estate E Estate F Estate G Vine-growing farm  Vine-growing area Sauternes Entre-deux-Mers Entre-deux-Mers Medoc Graves Blayais Blayais  Inter-row spacing (cm) 150 160 250 160 250 210 200  Intra-row spacing (cm) 100 100 100 100 120 100 100  Trellis height (cm) 140 160 210 150 180 150 170 Wire-lifting task  Start time (hh:mm) 07:32 07:27 08:49 08:06 08:22 07:03 07:56  Duration (mn) 71 87 98 88 120 107 108  Dry-bulb temperature (°C) 19.0 22.8 24.5 18.1 21.4 18.7 24.4  Relative humidity (%) 81 77 70 70 83 91 71 View Large Participants and re-entry equipment A total of 42 workers (six per vineyard) volunteered to take part in the study and provided written informed consent. The re-entry task under study was vine-lifting (or trellising). Part of canopy management, this task consists of lifting metal wires along rows while arranging new fruiting shoots (which tend to grow sideways) into a vertical position. Shoot positioning allows the spread of shoots to promote an open canopy, improve spray penetration, and adhere to the shape of the given trellis system. Each worker reentered fields between 12 and 24 h after pesticide spraying and was asked to follow the usual working practices. To reduce heterogeneity, the task duration was the same for the six workers from a given vineyard. Three different types of PPE were allocated randomly in each vineyard by the team coordinator (two workers per type): the HF Estufa polyamide garment (Brisa®), composed of an Arabic cap (a hood fitting over the head and covering the shoulders), a blouse, and entire pants; the Tyvek® Classic Plus garment, a category III—type 4 hooded coverall (DuPont®), composed of flash spun high-density polyethylene; the Tychem® C Standard garment, a category III—type 3 hooded coverall (DuPont®), featuring a Tyvek® substrate with a polymeric coating. Additional gear items were AlphaTec® 58–270 chemical resistant gloves (Ansell®), which are composed of double wall nitrile and seamless nylon liner, and rubber boots. No masks were worn. For undergarments, all subjects wore identical disposable two-piece long johns (100% cotton). Each worker’s practice was observed throughout the vine-lifting task by a field staff member. Sociodemographic characteristics, potential determinants of physiological strain and task-related factors were collected using a structured questionnaire. Any specific occurrences that could affect physiological strain were noted on the observation forms. At the end of the vine-lifting task, the field monitor conducted an unstructured interview to elicit the worker’s feelings regarding the work conditions and the comfort of the PPE. Environmental conditions Weather conditions were documented one to two times during the vine-lifting task. Dry-bulb temperature ranged from 19.0 to 24.5°C between vineyards (Table 1). On several occasions, a wind speed higher than 3 m/s (maximum 6 m/s) was recorded during field monitoring, as is typically encountered during this season. Humid conditions corresponded to dew, damp, or even a short rainfall episode (approximately 10 mm of rain fell during the monitoring in vineyard A). To mimic dew, controlled humidity was operated at two sites: vineyard D: water was sprayed on the vineyard using a tractor-trailed broadcast air-assisted sprayer some rows ahead of the team; vineyard E: water was sprayed on the vineyard using sprinklers that were already present in the field and were opened for a period of time some rows ahead of the team. As a result, the relative humidity ranged from 70 to 91% across field sites (Table 1). Assessment of physiological costs Skin temperature was measured using a Proges Plus® 22L thermo-button (with an accuracy of ±0.1°C) placed against the skin on the tibia (just above the ankle) of each worker. This area was chosen to avoid interfering with vineyard farming activities and was worn throughout the task. Measurements were recorded once per minute. The skin temperature was assessed at rest before starting vine-lifting, and the mean skin temperature was calculated during work. Each of the workers was equipped with a Polar® RS800 heart rate monitor, which included an adjustable chest strap equipped with a heartbeat detector and a wrist receiver to which the heart rate (HR) was transmitted. The HR was recorded at a regular interval of 5 s. All workers were fitted with a HR monitor before putting on their protective equipment. Resting HR (HRrest) was estimated through the first percentile value of the HR recording (Malchaire et al., 1986). The net cardiac cost (NCC) represented the difference between the mean HR (HRmean) and HRrest. The theoretical maximum HR (TMHR) was defined by the Gellish formula (207 − 0.7 × age) (Gellish et al., 2007). Heart rate reserve (HRR) was the difference between TMHR and HRrest. The relative cardiac cost (RCC) expressed the NCC as a percentage of the HRR (NCC/HRR). Following Meunier et al. (1994), a cardiac workload score was calculated. This summed composite index relies on HRmean, RCC and the 99th percentile for HR (HR99), and ranges from 5 to 15. Statistical analyses The following data were considered at the individual level: age (years), gender (female/male), body mass index (BMI, kg/m2), experience in vine lifting (years), handedness (left-handed, right-handed), type of protective clothing (three categories with the HF Estufa polyamide garment as reference category), skin temperature at rest (°C), mean skin temperature during work (°C), and cardiac strain indices (mean HR, bpm; 99th percentile for HR, bpm; RCC, %; cardiac workload score, unitless). Because one worker lost her thermos-button, the missing temperature values were replaced by the modal values from remaining participants. Additional information was collected at the vineyard level: air temperature, relative humidity, inter- and intra-row spacing, trellis height, and task duration. The data for analysis form a hierarchical structure as workers are nested within vineyards. The observations within a particular vineyard therefore are more alike than are observations from different vineyards due to the shared occupational, climatic, and geographical environments experienced within the vineyard. Left unaddressed, this clustering effect causes standard errors to be underestimated, which can lead to incorrect inferences. To consider the potential correlation of the data within vineyards, multivariate multilevel linear regression models were carried out using the distribution-free MCMC method and following the general formula (random intercept model): yij=β0+Σβxi+Σβxij+υ0j+υij with yij: physiological quantitative variable, β0: fixed effect intercept, βxi: vineyard fixed effects, βxij: worker fixed effects, υ0j: vineyard random effect, and υij: worker random effect. Associations between various physiological indices (dependent variables) and PPE type (independent variable) were examined using multilevel linear regression models adjusting for other risk factors. The covariates (defined at either the worker or vineyard level) were introduced into multivariate models as confounding factors provided they were associated both with the physiological index under study and PPE type (P < 0.20). All analyses were performed using MLwiN software version 2.24 (Centre for Multilevel Modelling, Bristol University, UK). Results Description of the population Most of the workers involved in the study were female (25 of 42 workers) (Table 2). According to their BMI, 40.5% of the workers could be considered overweight, and 11.9% were obese. Ages ranged from 19 to 64 years. Experience in vineyard lifting ranged from zero to more than 45 years. Most workers were right-hand dominant (88.1%). None of these characteristics differed according to the PPE type (P > 0.36). Table 2. Characteristics of re-entry vineyard workers according to the personal protective equipment (n = 14 per group, number (percentage)). HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Age (years)a  <30 3 (21.4) 3 (21.4) 1 (7.1) 7 (16.7)  30–39 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.4)  40–49 1 (7.1) 2 (14.3) 3 (21.4) 6 (14.3)  ≥50 3 (21.4) 4 (28.6) 5 (35.7) 12 (28.6) Gender  Female 8 (57.1) 8 (57.1) 9 (64.3) 25 (59.5)  Male 6 (42.9) 6 (42.9) 5 (35.7) 17 (40.5) Body mass index (kg/m2)a  ≤25 6 (42.9) 6 (42.9) 8 (57.1) 20 (47.6)  25–29.9 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.5)  ≥30 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9) Experience in the vine-lifting task (years)a  <5 2 (14.3) 3 (21.4) 2 (14.3) 7 (16.7)  5–9 4 (28.6) 1 (7.1) 6 (42.9) 11 (26.2)  10–14 2 (14.3) 5 (35.7) 1 (7.1) 8 (19.0)  15–19 2 (14.3) 4 (28.6) 0 (0.0) 6 (14.3)  20–24 0 (0.0) 1 (7.1) 2 (14.3) 3 (7.1)  ≥25 4 (28.6) 0 (0.0) 3 (21.4) 7 (16.7) Handedness  Left-handed 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9)  Right-handed 13 (92.9) 11 (78.6) 13 (92.9) 37 (88.1) HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Age (years)a  <30 3 (21.4) 3 (21.4) 1 (7.1) 7 (16.7)  30–39 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.4)  40–49 1 (7.1) 2 (14.3) 3 (21.4) 6 (14.3)  ≥50 3 (21.4) 4 (28.6) 5 (35.7) 12 (28.6) Gender  Female 8 (57.1) 8 (57.1) 9 (64.3) 25 (59.5)  Male 6 (42.9) 6 (42.9) 5 (35.7) 17 (40.5) Body mass index (kg/m2)a  ≤25 6 (42.9) 6 (42.9) 8 (57.1) 20 (47.6)  25–29.9 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.5)  ≥30 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9) Experience in the vine-lifting task (years)a  <5 2 (14.3) 3 (21.4) 2 (14.3) 7 (16.7)  5–9 4 (28.6) 1 (7.1) 6 (42.9) 11 (26.2)  10–14 2 (14.3) 5 (35.7) 1 (7.1) 8 (19.0)  15–19 2 (14.3) 4 (28.6) 0 (0.0) 6 (14.3)  20–24 0 (0.0) 1 (7.1) 2 (14.3) 3 (7.1)  ≥25 4 (28.6) 0 (0.0) 3 (21.4) 7 (16.7) Handedness  Left-handed 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9)  Right-handed 13 (92.9) 11 (78.6) 13 (92.9) 37 (88.1) aFor the sake of clarity, this variable is categorized in the table, but it was introduced into multilevel regression models as a continuous variable. bNone of the characteristics differed according to the PPE type (P > 0.36). View Large Table 2. Characteristics of re-entry vineyard workers according to the personal protective equipment (n = 14 per group, number (percentage)). HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Age (years)a  <30 3 (21.4) 3 (21.4) 1 (7.1) 7 (16.7)  30–39 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.4)  40–49 1 (7.1) 2 (14.3) 3 (21.4) 6 (14.3)  ≥50 3 (21.4) 4 (28.6) 5 (35.7) 12 (28.6) Gender  Female 8 (57.1) 8 (57.1) 9 (64.3) 25 (59.5)  Male 6 (42.9) 6 (42.9) 5 (35.7) 17 (40.5) Body mass index (kg/m2)a  ≤25 6 (42.9) 6 (42.9) 8 (57.1) 20 (47.6)  25–29.9 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.5)  ≥30 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9) Experience in the vine-lifting task (years)a  <5 2 (14.3) 3 (21.4) 2 (14.3) 7 (16.7)  5–9 4 (28.6) 1 (7.1) 6 (42.9) 11 (26.2)  10–14 2 (14.3) 5 (35.7) 1 (7.1) 8 (19.0)  15–19 2 (14.3) 4 (28.6) 0 (0.0) 6 (14.3)  20–24 0 (0.0) 1 (7.1) 2 (14.3) 3 (7.1)  ≥25 4 (28.6) 0 (0.0) 3 (21.4) 7 (16.7) Handedness  Left-handed 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9)  Right-handed 13 (92.9) 11 (78.6) 13 (92.9) 37 (88.1) HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Age (years)a  <30 3 (21.4) 3 (21.4) 1 (7.1) 7 (16.7)  30–39 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.4)  40–49 1 (7.1) 2 (14.3) 3 (21.4) 6 (14.3)  ≥50 3 (21.4) 4 (28.6) 5 (35.7) 12 (28.6) Gender  Female 8 (57.1) 8 (57.1) 9 (64.3) 25 (59.5)  Male 6 (42.9) 6 (42.9) 5 (35.7) 17 (40.5) Body mass index (kg/m2)a  ≤25 6 (42.9) 6 (42.9) 8 (57.1) 20 (47.6)  25–29.9 7 (50.0) 5 (35.7) 5 (35.7) 17 (40.5)  ≥30 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9) Experience in the vine-lifting task (years)a  <5 2 (14.3) 3 (21.4) 2 (14.3) 7 (16.7)  5–9 4 (28.6) 1 (7.1) 6 (42.9) 11 (26.2)  10–14 2 (14.3) 5 (35.7) 1 (7.1) 8 (19.0)  15–19 2 (14.3) 4 (28.6) 0 (0.0) 6 (14.3)  20–24 0 (0.0) 1 (7.1) 2 (14.3) 3 (7.1)  ≥25 4 (28.6) 0 (0.0) 3 (21.4) 7 (16.7) Handedness  Left-handed 1 (7.1) 3 (21.4) 1 (7.1) 5 (11.9)  Right-handed 13 (92.9) 11 (78.6) 13 (92.9) 37 (88.1) aFor the sake of clarity, this variable is categorized in the table, but it was introduced into multilevel regression models as a continuous variable. bNone of the characteristics differed according to the PPE type (P > 0.36). View Large The re-entry task lasted between 71 and 108 min according to the vineyard (Table 1). As for the other wire-lifting task characteristics, no difference was found between the three PPEs (P = 1.00) because of their random allocation within estates. Physiological costs Heat and cardiac strain parameters are reported in Table 3. No significant difference was found for either skin temperature at rest or mean skin temperature during work in different garments, with overall mean temperatures of 32.1°C and 33.3°C, respectively. Table 3. Physiological strain in re-entry workers according to the PPE (n = 14 per group, mean (standard deviation), multilevel regression analysis). HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Skin temperature at rest (°C) 32.0 (1.2) 31.9 (1.2) 32.4 (0.7) 32.1 (1.0) Mean skin temperature during work (°C) 33.1 (1.2) 33.2 (1.5) 33.6 (0.8) 33.3 (1.2) Mean heart rate (bpm) 99.8 (10.9) 101.1 (13.1) 108.7a (12.7) 103.0 (12.6) 99th Percentile for heart rate (bpm) 115.3 (15.8) 120.6 (20.2) 136.5a (31.4) 124.0 (24.6) Relative cardiac cost (%) 17.6 (4.5) 21.0 (9.5) 24.4a (9.2) 21.0 (8.4) Cardiac workload score (unitless) 5.7 (2.8) 6.9 (3.5) 8.9b (3.8) 7.1 (3.6) HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Skin temperature at rest (°C) 32.0 (1.2) 31.9 (1.2) 32.4 (0.7) 32.1 (1.0) Mean skin temperature during work (°C) 33.1 (1.2) 33.2 (1.5) 33.6 (0.8) 33.3 (1.2) Mean heart rate (bpm) 99.8 (10.9) 101.1 (13.1) 108.7a (12.7) 103.0 (12.6) 99th Percentile for heart rate (bpm) 115.3 (15.8) 120.6 (20.2) 136.5a (31.4) 124.0 (24.6) Relative cardiac cost (%) 17.6 (4.5) 21.0 (9.5) 24.4a (9.2) 21.0 (8.4) Cardiac workload score (unitless) 5.7 (2.8) 6.9 (3.5) 8.9b (3.8) 7.1 (3.6) aP = 0.03 (reference category: HF Estufa polyamide garment). bP = 0.01 (reference category: HF Estufa polyamide garment). cThe associations between physiological strain parameters and PPE type were not confounded by any worker- or vineyard-level variable (P > 0.20). Therefore, the final regression models only included the PPE type as independent variable. View Large Table 3. Physiological strain in re-entry workers according to the PPE (n = 14 per group, mean (standard deviation), multilevel regression analysis). HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Skin temperature at rest (°C) 32.0 (1.2) 31.9 (1.2) 32.4 (0.7) 32.1 (1.0) Mean skin temperature during work (°C) 33.1 (1.2) 33.2 (1.5) 33.6 (0.8) 33.3 (1.2) Mean heart rate (bpm) 99.8 (10.9) 101.1 (13.1) 108.7a (12.7) 103.0 (12.6) 99th Percentile for heart rate (bpm) 115.3 (15.8) 120.6 (20.2) 136.5a (31.4) 124.0 (24.6) Relative cardiac cost (%) 17.6 (4.5) 21.0 (9.5) 24.4a (9.2) 21.0 (8.4) Cardiac workload score (unitless) 5.7 (2.8) 6.9 (3.5) 8.9b (3.8) 7.1 (3.6) HF Estufa polyamide Tychem® C Standard Tyvek® Classic Plus Total Skin temperature at rest (°C) 32.0 (1.2) 31.9 (1.2) 32.4 (0.7) 32.1 (1.0) Mean skin temperature during work (°C) 33.1 (1.2) 33.2 (1.5) 33.6 (0.8) 33.3 (1.2) Mean heart rate (bpm) 99.8 (10.9) 101.1 (13.1) 108.7a (12.7) 103.0 (12.6) 99th Percentile for heart rate (bpm) 115.3 (15.8) 120.6 (20.2) 136.5a (31.4) 124.0 (24.6) Relative cardiac cost (%) 17.6 (4.5) 21.0 (9.5) 24.4a (9.2) 21.0 (8.4) Cardiac workload score (unitless) 5.7 (2.8) 6.9 (3.5) 8.9b (3.8) 7.1 (3.6) aP = 0.03 (reference category: HF Estufa polyamide garment). bP = 0.01 (reference category: HF Estufa polyamide garment). cThe associations between physiological strain parameters and PPE type were not confounded by any worker- or vineyard-level variable (P > 0.20). Therefore, the final regression models only included the PPE type as independent variable. View Large The PPE types always ranked in the same order regardless of the cardiac strain parameter considered. The best results were found for the HF Estufa polyamide garment, while the poorest results were observed for the Tyvek® Classic Plus garment, with a significant demonstration (P ≤ 0.03). The most significant finding (P = 0.01) was observed for the cardiac workload score (mean: 8.86, 6.86, and 5.71 for the Tyvek® Classic Plus garment, the Tychem® C Standard coverall, and the HF Estufa polyamide garment, respectively). The associations between physiological strain parameters and PPE type were not confounded by any worker- or vineyard-level variable (P > 0.20). Therefore, the final regression models only included the PPE type as independent variable (Table 3). Discussion Field observations provided original data on physiological burdens for workers under a standard agricultural scenario (vine-lifting in a vineyard). The findings suggest that cardiac strain was not related to the vineyard characteristics, climatic circumstances, work conditions, or individual sociodemographic characteristics. Instead, cardiac strain was related to the type of PPE worn by workers during the re-entry task. This study has several strengths. First, we used an experimental design with random assignment of vineyard workers to PPE garments, independently of the worker’s perception regarding their comfort level. Second, work conditions and practices were representative of the conditions typically encountered during professional lifting in vineyards. Third, temperature and HR monitoring provided a more objective measurement of the physiological reactions of vineyard workers than the use of discomfort perception (such as the Borg scale of perceived exertion), which is usually determined by a combination of physiological, psychological, and physical factors. Fourth, we used a sound statistical methodology. Because multilevel modeling techniques consider the hierarchical structure of the data, all climatic and topographic parameters of the seven vineyards were accounted for by the two-level regression models. There are a few limitations to this study that should be noted. First, the sample size (42 workers) was modest, although the statistical power was sufficient to highlight differences between PPE garments. Second, some individual variables were missed (e.g. education level) to adjust for and reduce potential residual confounding, although the random allocation of PPEs minimized this bias. Third, we were well aware of the ISO 9886 4-point method used in hot conditions for estimating mean skin temperature (ISO 9886). However, to ensure worker acceptance and to avoid interfering with the demanding vine-lifting task, only one thermo-button was placed against the skin of the tibia (one of the four recommended sites). As skin temperature was measured at the same site for all workers, comparisons could be made across PPE type. The physiological gradations of different activities have been proposed by researchers in the field of work physiology based on various cardiac strain indices. According to the mean cardiac workload score (7.14) found in this study, the workload associated with vine-lifting can be classified as fairly difficult in nature (Meunier et al., 1994). The same conclusion is reached when relying on the sole RCC (mean: 21.0%) (Chamoux et al., 1985). Differences in cardiac strain were observed according to the PPE worn. Not surprisingly, the HF Estufa polyamide garment resulted in the lowest cardiac stress. This three-piece lightweight garment fits rather comfortably compared to full-body PPEs (often considered not comfortable under typical agricultural conditions); for example, this PPE allowed workers to remove the hood when they were standing for a while at the end of the rows. Workers found it to be lighter and more effective against humidity than the raincoat they usually wore. In contrast, the highest cardiac strain demonstrated with the Tyvek® Classic Plus garment compared to the Tychem® C Standard garment was not anticipated. The former is lighter (41 g/m2 versus 83 g/m2), thinner (130 µm versus 170 µm), and presents some water vapor permeability (1700 g/m2. 24 h versus impermeability). Therefore, the latter could be expected to increase the metabolic cost of performing the vine-lifting task by adding weight, limiting ability, and reducing the evaporation of perspiration. PPE design and thermal stress were similar between both types of coveralls. Field observations provided insight into this intriguing finding. Six workers (five of whom wore the Tyvek® Classic Plus garment) spontaneously complained about humidity (not sweat) having reached their underwear. Four of the six workers more precisely described their body parts affected by humidity (“forearms and legs”, “above the knees”, “left thigh”, “thighs and lower legs”). We therefore assumed that undergarment humidity places an additional physiological burden on vineyard workers; under the (very) humid conditions encountered during the field study, the thinness and breathability of the Tyvek® Classic Plus garment became liabilities in terms of cardiac strain, thus confirming the influence of environmental conditions on PPE performance. Conversely, the water-repellent properties of the Tychem® C Standard garment seemed to confer a decisive advantage. Our results cannot be easily compared to those of others. Indeed, to our knowledge, very few field studies in the scientific literature have monitored the cardiac burden of farming activities (Costa et al., 1989; Singh et al., 2011; Sahu et al., 2013), and none of them compared the performance of different PPE types. Conclusion Additional interventions are needed among workers who have indirect contact with substances through re-entry tasks, thus raising the issue of new PPE recommendations for canopy management in vineyards. All PPEs should fit comfortably to encourage their use among vineyard workers and to promote safe workplace behaviors (Akbar-Khanzadeh et al., 1995). Our PPE assessment indicated that the properties of the coverall fabric influence the cardiac strain in vine-workers under a specific work scenario (vine-lifting in very humid conditions). These results confirm that the idea of using generic coveralls in any farming activity is unsuitable. Compromises are necessary to balance physiological costs and protection, depending on the agricultural task performed, the crop grown, and the environmental conditions encountered. The public health objective of vineyard worker safety compliance requires additional field investigations and technical innovations among manufacturers, health and safety specialists, and ergonomists. Declaration The Union des Industries de la Protection des Plantes (French Crop Protection Industry Association) funded the National Research Institute of Science and Technology for Environment and Agriculture for the field study within the framework of the Safe Use Initiative project. The funder had no role in the design or conduct of this study, the analysis or interpretation of the data, or the preparation of this manuscript. Acknowledgments We are grateful to the vineyard workers, vineyard managers, and field monitors who made this study possible. The authors have no conflicts of interest or financial relationships to disclose. Subjects included in the study volunteered, gave their written informed consent, and were observed in the course of their normal work activities. Therefore, no approval from an ethics committee was required by French regulations at the time of the study. References Akbar-Khanzadeh F , Bisesi MS , Rivas RD . ( 1995 ) Comfort of personal protective equipment . Appl Ergon ; 26 : 195 – 8 . Google Scholar Crossref Search ADS PubMed Ambiaud E . ( 2015 ) Vineyard practices survey – phytosanitary treatments [in French] . Montreuil sous Bois (France): Agreste Les Dossiers 2015 , n 28. Available at http://agreste.agriculture.gouv.fr/IMG/pdf/dossier28_integral.pdf. Accessed 8 December 2017 . Baldi I , Lebailly P , Bouvier G et al. ( 2014 ) Levels and determinants of pesticide exposure in re-entry workers in vineyards: results of the PESTEXPO study . Environ Res ; 132 : 360 – 9 . 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Published by Oxford University Press on behalf of the British Occupational Hygiene Society. This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - Physiological Strain in French Vineyard Workers Wearing Protective Equipment to Conduct Re-Entry Tasks in Humid Conditions
JF - Annals of Work Exposures and Health (formerly Annals Of Occupational Hygiene)
DO - 10.1093/annweh/wxy056
DA - 2018-10-15
UR - https://www.deepdyve.com/lp/oxford-university-press/physiological-strain-in-french-vineyard-workers-wearing-protective-33agIWqJKC
SP - 1040
VL - 62
IS - 8
DP - DeepDyve
ER -