Occupational Heat Stress and Kidney Health in Salt Pan Workers

Introduction

Work in heat affects millions of workers. Although kidney function in agricultural workers is increasingly researched, nonagricultural studies are scarce. In coastal salt pans, the absence of occupational exposures to pesticides and other toxicants allows assessment of heat stress alone.

Methods

Seven Indian salt pans were surveyed from 2017 to 2020. Job-specific workload was assessed. Heat stress was characterized as exceeding the wet bulb globe temperature (WBGT)-threshold limit value (TLV) for high and moderate workloads. Preshift and postshift heart rates (HRs), tympanic temperatures, and urine specific gravity (USG) were measured for 352 workers, as were sweat rates (SwR), serum creatinine (SCr), serum uric acid, and urine dipstick. Estimated glomerular filtration rate (eGFR; ml/min per 1.73 m²) was computed. Heat-strain symptoms were assessed using questionnaires.

Results

The mean WBGT was 30.5 ± 1.3 °C (summer) and 27.8 ± 1.9 °C (winter). Water intake during the workday was low, median was one Litre, and most workers (87%) exceeded the TLV for heat stress. Dehydration-related symptoms were frequent in those with high-heat stress, as were cross-shift increases in temperature (≥1°C; 15%), a high USG (≥1.020; 28%), and a high SwR (≥1 l/h; 53%). An eGFR of 60 to 89 ml/min per 1.73 m² was observed in 41% of all workers examined, and 7% had eGFR below 60 ml/min per 1.73 m². The odds ratio for eGFR <90 ml/min per 1.73 m² in workers exceeding the TLV, compared to workers below this limit, adjusted for age and gender was 2.9 (95% CI: 1.3-6.4).

Conclusion

Workplace interventions to prevent heat stress and dehydration in the salt pans and other at-risk industries are urgently required. The findings strengthen the notion that high-heat stress and limited hydration is a risk factor for kidney dysfunction.

Immunomodulation in age-related disorders and nanotechnology interventions

Recently, the aging population has increased exponentially around the globe bringing more challenges to improve quality of life in those populations while reducing the economic burden on healthcare systems. Aging is associated with changes in the immune system culminating in detrimental effects such as immune dysfunction, immunosenescence, and chronic inflammation. Age-related decline of immune functions is associated with various pathologies including cardiovascular, autoimmune, neurodegenerative, and infectious diseases to name a few. Conventional treatment addresses the onset of age-related diseases by early detection of risk factors, administration of vaccines as preventive care, immunomodulatory treatment, and other dietary supplements. However, these approaches often come with systemic side-effects, low bioavailability of therapeutic agents, and poor outcomes seen in the elderly. Recent innovations in nanotechnology have led to the development of novel biomaterials/nanomaterials, which explore targeted drug delivery and immunomodulatory interactions in vivo. Current nanotechnology-based immunomodulatory approaches that have the potential to be used as therapeutic interventions for some prominent age-related diseases are discussed here. Finally, we explore challenges and future aspects of nanotechnology in the treatments of age-related disorders to improve quality of life in the elderly. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Cardiovascular Disease Therapeutic Approaches and Drug Discovery > Nanomedicine for Neurological Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Evaluation of 13-week subchronic toxicity of Platycodon grandiflorus (Jacq.) A.DC. root extract in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Platycodi radix is widely used in traditional herbal medicine for bronchitis, asthma, pulmonary tuberculosis, hypertension, hyperlipidemia, and diabetes. However, data on safety of Platycodi radix are insufficient.

AIM OF THE STUDY

The present study was performed to evaluate the potential subchronic toxicity of Platycodi radix water extract through a 13-week repeated oral dose experiment in Sprague-Dawley rats.

MATERIALS AND METHODS

Forty male and 40 female rats were randomly assigned to four experimental groups: three treatment groups receiving 300, 1000, and 3000 mg/kg/day of Platycodi radix water extract and a vehicle control group receiving sterile distilled water for 13 weeks.

RESULTS

Repeated oral administration of the Platycodi radix water extract to rats resulted in an increased incidence of centrilobular hepatocellular hypertrophy in the liver, diffuse follicular cell hypertrophy in the thyroid gland, and squamous hyperplasia of the limiting ridge in the stomach at dose levels of ≥500 mg/kg/day of both genders. However, these findings are considered be adaptive non-adverse changes because these findings were observed without organ weight change or clinical pathology alterations. No treatment-related effects on clinical signs, body weight, food and water consumption, ophthalmic examination, urinalysis, hematology, serum biochemistry, necropsy findings, and organ weights were observed at any dose tested.

CONCLUSION

Under the present experimental conditions, the no-observed-adverse-effect level of the Platycodi radix water extract was considered to be ≥ 3000 mg/kg/day in rats, and no target organs were identified.