**4. Conclusions**

This occupational exposure assessment studied the application scenario of a stretcher-type electric sprayer, using the apple tree as an example. This is a typical Chinese orchard application scenario. This is the first time a study has focused on occupational pesticide exposure in orchards in China. The data from this study are a valuable guide for the application of pesticides on fruit trees such as citrus, pear, peach, and other small shrub type fruit trees.

In this study, we performed a systematic occupational exposure assessment on stretcher-type electric sprayer application of SYP-9625 in Chinese orchard fields using standard whole-body dosimetry and air sampling methodologies. We also verified the method of extracting and detecting SYP-9625 from various matrix materials. The results indicate that the hand is the most exposed body part and needs special protection. However, the total exposure is at the same level as that shown in other countries' research. One layer of clothing could protect from dermal exposure, causing a reduction of approximately 86%. Therefore, long trousers and waterproof gloves are necessary to protect the health and safety of the handler. The stretcher-type electric sprayer is China's most important orchard application equipment, but its related occupational exposure data are scarce. Therefore, it is necessary to strengthen the data in this research area.

Our experiment was only carried out in Beijing, and more studies should be performed to obtain extensive experimental results in the future. Our data might help establish accurate and strategic predictive exposure models and databases for risk assessment and pesticide registration.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2076-3417/10/23/8684/s1, Table S1: Mass spectrometric parameters for UPLC-MS determination of SYP-9625 concentrations, Figure S1: the structure of SYP-9625, Figure S2: the UPLC-MS chromatogram for SYP-9625.

**Author Contributions:** Experimental design, Z.W. and D.S.; investigation, Z.W. and Y.M.; data analysis, Z.W. and Y.M.; writing—original draft, Z.W. and Y.M.; writing—review and editing, X.M. (Xiangdong Mei) and D.S.; funding acquisition, D.S. and X.M. (Xiaodong Ma); supervision, J.N. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by The National Key Research and Development Program of China (grant number 2016YFD0200201), the National Natural Science Foundation of China (grant number 31772175), and the National Natural Science Foundation of China (grant number 31621064).

**Conflicts of Interest:** The authors declare no conflict of interest.
