Acute and Subacute Inhalation Toxicity of Highly Purified Phosphine (PH 3 ) in Male ICR Mice

Quercetin Protected from Aluminum Phosphide-induced Acute and Subacute Cardio- and Hepatotoxicity in Rats

BACKGROUND

Aluminum phosphide (ALP) intoxication either accidentally or intentionally, is one of the major health concerns in developing countries. Its poisoning causes severe damage to organs including the heart and liver.

OBJECTIVES

This study aimed to investigate the hepato- and cardioprotective effects of quercetin (QCN) on the acute/subacute toxicity of ALP in rodent models.

METHODS

Acute (single dose, 12.5 mg/kg, orally) and subacute (2 mg/kg, orally and 7 days) intoxication of ALP were induced in rats and the protective effects of QCN on altered hepatic/cardiac functional enzyme concentrations, myeloperoxidase activity, oxidative stress biomarkers, and histopathological changes were studied at three doses of 10, 50 and 100 mg/kg BW. To record any heart abnormality, an electrocardiogram (ECG) was recorded 3 h after the last treatment.

RESULTS

Quercetin reduced the ALP-increased hepatic and cardiac functional enzyme concentrations and myeloperoxidase activity. Moreover, QCN improved remarkably the ALP-induced ECG abnormalities (T inversion, bigeminy in R waves) and arrhythmias. QCN attenuated significantly (p < 0.05) the ALP-induced oxidative/ nitrosative stress and histopathological injuries in the liver and heart.

CONCLUSION

Our results suggest that QCN is able to protect the ALP-induced cardiac and hepatic injuries in both acute and subacute models and its effects attribute to its antioxidant and anti-inflammatory properties.

Worker exposure standard for phosphine gas

The 1998 U.S. Environmental Protection Agency Office of Pesticide Programs (OPP) re-registration eligibility decision (RED) for phosphine fumigants has generated much interest in defining safe levels of exposure for workers and worker bystanders. This report summarizes the pertinent literature on phosphine toxicity, including animal inhalation studies and human epidemiology studies, and also describes a margin-of-exposure (MOE) analysis based on available worker exposure data. In addition, a safe occupational exposure limit is estimated using typical OPP assumptions, after determination of appropriate uncertainty factors, based on quality of data in the principal study and pharmacokinetic considerations. While a conservative 8-hour time-weighted average (TWA) of 0.1 ppm was calculated, the overall weight of evidence, from a risk-management perspective, supports a conclusion that an occupational TWA of 0.3 ppm provides adequate health protection. In addition, a 15-minute short-term exposure limit (STEL) of 3 ppm was estimated. Finally, in contrast to the MOE analysis described in the OPP's phosphine RED, the MOE analysis described herein does not indicate that fumigation workers are currently being exposed to unacceptable levels of phosphine. Collectively, these findings support the occupational exposure limits of 0.3 ppm (8-hour TWA) and 1 ppm (STEL) established in the updated applicator's manuals for phosphine-generating products, which recently received approval from OPP.