Abstract:

This study was aimed to investigate the application of processing factors to dietary exposure assessment of
chlorpyrifos in cowpea during cooking in different age groups of different genders. Subjects of different ages were divided
into 10 groups: 2－3 years old, 4－6 years old, 7－10 years old, 11－13 years old, 14－17 years old, 18－29 years old, 30－
44 years old, 45－59 years old, 60–69 years old and ≥ 70 years old. The results showed the processing factors of cowpea
were obtained in different cooking modes after cleaning such as stir frying, microwave cooking, blanching and marination.
The chronic exposure risk index (CRfD) range was 7.5741－23.5425, lower than 100 and thus acceptabl, whereas the CRfD
range was 57.3599－111.0397 without taking the processing factors into consideration and the values in groups of 2－3, 4－
6 and 7－10 of both genders ranged from 102.0552 to 111.0397, which were higher than 100 and highly risky for subjects
in these groups. Accordingly, CRfD values not based on processing factors were 5－10 times more than those based on
processing factors. The value of dietary exposure assessment was more precise by considering the influence of processing
factors on chlorpyrifos in cowpea. All the different cooking modes following cleaning were effective to remove chlorpyrifos
residues from cowpea and microwave cooking showed the best effect.

Key words: cooking, chlorpyrifos, processing factor, dietary exposure assessment, chornic exposure risk index