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.