Phase 1: Recommendations and Findings

Sugarcane worker workloads
Photo Credit: Bonsucro / Joe Woodruff


Phase 1 of the Adelante Initiative was focused on establishing a baseline. This baseline was used to characterize exposures, assess risks and make initial recommendations for improved practices. This baseline will serve as a point of comparison as recommendations are made and implemented throughout the project. The objective being that kidney injury and heat stress events should decrease among the workforce with improved practices.

During Phase 1, four worker categories were selected with similar environmental exposures, but differentiated by observed workload. Workload serves as a proxy for heat stress. Cane cutters were the heaviest workload, followed by seed cutters, then drip irrigation repair workers and finally field support staff, including supervisors and nurses. Biological, qualitative and questionnaire data were collected and analyzed at the beginning and end of the harvest to assess what risk factors emerged for kidney damage and which groups were most at risk. What follows are the key findings from Phase 1, relevant recommendations for producers and researchers, as well as the relevance to other stake holders.

Adelante Phase 1
Photo Credit: Bonsucro / Joe Woodruff

Key Findings


Kidney decline appears to be associated with work load
(heaviest workload = most severe decline in kidney function)

Preliminary analysis shows burned cane cutters are 12 times more likely than other jobs to have elevated creatinine (indicator of kidney dysfunction). A lower proportion of seed cutters also have elevated creatinine at the end of harvest. This is consistent with the hypothesis that heat stress is a main driver of CKDu progression and potentially a main cause.

The current efforts at San Antonio Sugar Mill to reduce heat stress among the sugarcane workforce appear to be insufficient to prevent incident kidney injury (IKI) among cane cutters and to a lesser extent among the seed cutters. However, kidney injury was nearly absent in other workload categories that previously experienced declines in kidney function suggesting that the intervention that was implemented was sufficient for lower workloads.

Incident kidney injury increased with increasing heat stress according to job categories of field workers. Despite considerable improvements in working conditions, the job categories with highest heat stress still present kidney injury at an elevated rate (27% of burned cane cutters, 8% of seed cutters, 2.3% of drip irrigation repair workers and 1.9% field support workers). The risk of kidney injury was 14 times higher for cane cutters than for field support staff, and the risk for seed cutters was 4 times higher.


Potable water and electrolyte solutions must be available at rest sites and delivered directly to the workers if needed. All field workers and field support staff need rapid and easy access to sufficient potable water, including, 1) Personal water receptacles; 2) Access to shaded water coolers for refilling with cool water; 3) Reserve tanks carried on worker transport; and 4) Water quality needs assessment with minimum chlorination. Workers need to consume 1 liter/hour of water and 250 ml of electrolyte solution/hour


Rest breaks should be mandated for all field personnel rather than only ad hoc. Hydration operators, health promoters and supervisors should also have planned rest. Provide seated rest with sufficient space to cover all workers resting.


Portable shaded areas need to be near workers for shaded rest and to keep water supplies cool. Tents need to be moved for quick and easy access (≤ 50-75 meters). Tents much be sufficiently large to protect the number of workers under them, with alternating breaks if necessary. For example, the square meters of the roof of the tent should be equal to 1.25 meters square per worker. For instance, the tents at ISA are 16m2 for 20 workers (16×1.25=20). The roof of the tent should be 18” higher than the average height of the male population in country. Shaded refill stations should be set up throughout the work area and moved to keep close to the workers.

Logistics and Compliance

Implementation and management make all the difference. Great protocols for worker protection mean little if there is not proper monitoring and evaluation throughout the harvest to ensure guidelines are followed. A culture of transparency needs to exist, where anyone from a field worker to a manager can bring up concerns about implementation of interventions and report any problems as they arise.

The basic rest schedules for field workers must comply with the schedules laid out in the recommendation document and implementation guide available below, especially for burned cane and seed cutters. With time, heat conditions will be predicted more accurately on a daily basis and monitored more closely over the day with immediate responses prescribed (e.g., interruption of work, increased rest periods, more electrolyte solution).

The work/rest schedules evaluated during Phase 1 and those reported by other leading mills are insufficient

ISA’s 2017-2018 field practices and those published by Pantaleon are insufficient to protect workers. Further adherence to U.S. military and OSHA guidelines is essential. Evaluation of what is effective and whether protection is even possible in line with production expectations must be evaluated in Phase 2. Corrective actions have been taken at ISA and improved practices are being evaluated currently for Phase 2.

Determine occupational risk by job category with emphasis on work demands

  • Heat stress characteristics by job
  • Level of physical demand required by job
  • Estimate metabolic heat load by job
  • Design interventions to fit workload

Liquid access and intake during day

  • Develop protocol to asses water availability and water use
  • Design data collection for field support staff
  • Field observations should supplement data collection

Rest schedules

  • USARIEM evidence base to design schedules
  • Frequency and duration must be assessed for efficacy in mitigating heat stress
  • Use heart rate to estimate core temperature of sample
  • Adapt schedules as required

Assess protective clothing

  • Assessment of clothing worn by workers and what materials may improve heat management should be explored

Improve Machete and other field tools

  • A pilot to improve the machete used by cane cutters is underway to improve ergonomics and decrease workload. This will form basis of the evaluation and improvement of other field tools and personal protective equipment (PPE).

Focus on loan structure and client assessment

  • Assessment guidelines for loan officers on CKDu risks among workforce at client’s place of business are required and should be developed.
  • Loans contingent on the recipients committing to make improvements and disbursements of loans based on those improvements being validated would help ensure improved labor practices and a powerful incentive while limiting risk and liability.
  • Determine whether contracted and subcontracted workers receive the same interventions as in some contexts subcontracted workers receive subpar protections. Subcontracting should not be protection for sourcing cane produced using labor that does not receive protection based on the current best practices.

Focus on improving current certification standards

  • Recognize not all WRS systems are the same, validation is needed, key components like mobile tents and water access are essential.
  • Coordinate with researchers and form relationships with locally based organizations. Triangulate your data, mitigate your risk. Do not rely on one data point or one data source with which to assess field practices.
  • Determine whether contracted and subcontracted workers receive the same interventions as in some contexts subcontracted workers receive subpar protections. Subcontracting should not be protection for sourcing cane produced using labor that does not receive protection based on the current best practices.
  • Work with researchers to ensure labor portions of standards are adequate in protecting worker health. They should be at least in line with best available data as relevant protection measures are being validated.

Focus on site visits and validation

  • Coordinate announced and unannounced visits and make them part of your buying contract if not already done.
  • All points highlighted for banking and certification institutions are also for due consideration by sugarcane buyers be they brands or traders.


There was evidence for inflammation being part of the causal pathway

Cane cutters with kidney injury reported significantly more symptoms of fever, weakness and headache than cane cutters without, which is compatible with higher heat stress or an inflammatory response. Fever was associated with high levels of C-reactive protein (CRP) which is indicative of inflammation and previously indicated as related to heat stress in studies by the U.S. military. Of note, «fever» can occur due to both infection and heat stress. The current hypothesis among the Adelante Initiative research team is that reported fever is related to heat stress events primarily associated with workload as there is no plausible hypothesis as to why fever would be so much more common among the field laborer than the field support staff who work in the same field environment and have similar social economic positions.

There were no significant differences of CRP levels at start of harvest between job categories. At end of harvest, high CRP levels were more frequent, particularly among cane cutters, and in general, among any workers with kidney injury and a decline in kidney function.


Young men more likely to have significant decline in kidney function

Young men are the most at risk of kidney dysfunction, which is the opposite trend seen in the general population where older people generally have lower kidney function. At San Antonio Sugar Mill only men work as cane cutters. Among seed cutters, kidney injury occurrence was similar among woman and men.


Affected workers are more likely to leave employment (loss-to-follow-up) so findings are likely to be an underestimate

Workers at Ingenio San Antonio are rightly evaluated for kidney function, and those that have compromised function and do not recover after a set amount of time are released from the workforce. Workers may also self-select out of the workforce once their kidney function becomes compromised. This leads to what is known as the «Healthy Worker Effect». This means that there will be a preponderance of healthy workers remaining in the workforce at the end of a harvest and there is a tendency for sick workers to make up a significant portion of those who have left the workforce.

  • Account for drop-outs (Loss to Follow-up)
  • Locate those that leave the workforce
  • Assess kidney function (Point-of-care technology)
  • Gain resolution on reason for leaving


A lower kidney function pre-harvest is associated with decline in kidney function over the harvest.

Baseline kidney function was associated with kidney injury and declined kidney function during or at end of harvest. Those with highest creatinine at pre-harvest were at the highest risk of kidney decline over the harvest.

The mill’s creatinine level cut-off of 1.3 mg/dl for hiring male workers was too high. It has since been addressed and a more specific measure using age and creatinine levels ensures only healthy workers enter the workforce. Those with a creatinine near 1.3 mg/dl already have impaired kidney function. Those with impaired function are more likely to have greater damage done in adverse conditions.

Criteria for cut-off of SCr levels for hiring, especially hiring workers for the most strenuous jobs, is not sufficient. The estimated glomelular filtration rate (eGFR) should be calculated using the formula provided by the U.S National Kidney Foundation ( Workers with <90 eGFR should not be hired (especially for young workers) as a eGFR less than 90 is indicative of an already compromised kidney. Those with compromised kidney function are more likely to have rapid decline of kidney function when faced with difficult environmental and labor conditions.

If company records exist, the worker’s history of previous episodes of acute kidney injury must also be considered. Workers with acute kidney injury documented in their clinical records should be considered for less risky work.

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