Effect of Fipronil Exposure on Hematological Aspects of Rhesus Monkeys (Macaca mulatta): Risk and Toxicity Assessment in Agro-Workers

Abstract

Background

Fipronil (FPN) is a broad-spectrum phenylpyrazole insecticide, widely used in agriculture and veterinary medicine. Published research on FPN toxicity has established the fact that its inhalation or dermal exposure may lead to very serious clinical outcomes in non-target animals. In line to its exposure and toxicity related damage, FPN has been investigated in many invertebrates, however, its exposure-related noxiousness is less reported in higher animals.

Objective

To assess the FPN-induced effects to agro-workers in the field, in the present study, we used physiological human surrogates, adult rhesus monkeys as models.

Method

We exposed well habituated, chair restraint adult rhesus monkeys with a field spray concentration of FPN (0.3 mg/1 mL distilled water) through an inhalation route in the closed system. Animals were divided into control and treatment groups, each containing three animals. Inflammatory and hematological effects were determined by evaluating the kidney and liver biomarker enzymes; serum creatinine and alanine transaminase (ALT), aspartate transaminase (AST) levels respectively.

Results

Our findings reveal that FPN treated monkeys show significantly increased levels of ALT (p = 0.000461), AST (p = 0.0681) and creatinine (p = 0.00656) as compared to the control group. Furthermore, significant differences of red blood cells (RBCs) (p = 0.0139) and white blood cells (WBCs) (p = 0.00642) were also observed in the treated and control group monkeys which reflect strong toxic effects on the blood cells.

Conclusion

Our findings demonstrate that FPN exposure is very toxic to higher animals and causes severe damage to the liver and kidneys along with other clinical problems. The study highlights the effect and impact of passive inhalation of insecticides in intentionally carefree agro-workers and raises the concern of public awareness toward pesticides use.

Keywords:

• rhesus monkeys (Macaca mulatta)
• fipronil
• hepatic damage
• nephrotoxic
• pesticides use in Pakistan

Abbreviations

FPN, fipronil; EDTAA, ethylenediamine tetraacetic acid; ATL, alanine transaminase; AST, aspartate aminotransferase; PO₂, partial pressure of oxygen; RR, respiration rate; HB, heartbeat; Hb, hemoglobin; BP, blood pressure; RT, rectal temperature; RBC, red blood cell; WBC, white blood cells; CBC, complete blood count.

Acknowledgments

The authors are thankful to the National Veterinary Laboratory, Peshawar for their valued cooperation and Ponch University Azad, Kashmir and Henan University, China for the collaboration and funding in this project. The authors would like to pay countless thanks to Abdul Aziz, Abdul Basit, Syed Aftab Hussain Shah and Bilal Hussain, and Mr. Manzoor (Attendant Animal House) for their help in animal habituation and project administration.

Disclosure

The authors report no conflicts of interest in this work.

Additional information

Funding

This work was supported by the mutual funding grants from the Higher Education Commission of Pakistan and Quaid-I-Azam University, Islamabad and the Postgraduate Education Reform and Quality Improvement of Henan Province, China (No. YJS2022KC30, to E.J.).