A series of wound membranes of polyvinyl alcohol and recombinant spider silk protein (pNSR16) was prepared by electrospinning. The membrane was analyzed by scanning electron microscopy, atomic force microscopy, and Fourier transform infrared spectroscopy. The result showed that the three factors that affected average fiber diameter from high to low were, voltage, flow speed, and solidification distance; and the three factors that affected fiber uniformity from high to low were, flow speed, solidification distance, and voltage. The fibers adhered together after being dealt with alcohol. pNSR16 transformed from random coil into β-sheet after being immersed in alcohol. Additionally, the porosity of the electrospun membrane was 84.85%, which was higher than that of cast membrane prepared with the same composition. Experiments of applying electrospun membranes as wound dressing for Sprague Dawley rat wound healing showed that it could promote wound healing and basic fibroblast growth factor expression.

Heavy metal is widespread in food and the environment due to multiple origins, raising concerns over their persistent potential health risks. Contamination of multiple heavy metals in tea leaves is frequently reported. However, the dietary exposure risk that heavy metals in Tieguanyin tea (a famous type of oolong tea,) pose to different subpopulations has not been explored. In this study, contaminations of five heavy metals (Cu, Pb, Cr, Cd, and Ni) of concern in Tieguanyin tea were monitored, then the related health risk was assessed for six different subpopulations based on tea brewing experiments and a previous consumption survey. Results show that the mean levels found were as follows: 8.18 mg/kg (Cu), 0.84 mg/kg (Pb), 0.51 mg/kg (Cr), 0.04 mg/kg (Cd), and 1.90 mg/kg (Ni), respectively, and their transfer rates during tea brewing varied within 10.2–70.4%. All estimated daily intakes of individual targeted elements via Tieguanying tea consumption were far below their corresponding tolerable limits. The adjusted hazard index value ranged from 1.1 × 10⁻² to 1.7 × 10⁻², indicating that exposure to these five elements via drinking Tieguanyin tea would not pose significant non-cancer risks for six subpopulations under the current consumption habit. In addition, the carcinogenic risks associated with heavy metals (Pb, Cd, and Cr) were acceptable because no total cancer risk values exceeded the 10⁻⁴ threshold. However, in order to improve consumer protection, we still suggest that considerable attention should be paid to Pb, Ni, and Cd because of their high concentration in infusion, high extraction rate, and major carcinogenic risk contribution, respectively.

The objective of this study was to evaluate the residues of 42 pesticides subject to public concern in Tieguanyin tea produced in Fujian, China. The presence of 42 pesticide residues in 90 Tieguanyin tea samples were determined. A total of 17 pesticides were detected. At least one pesticide residue was detected in 65 samples (72.2%). The detected pesticides imidacloprid, tolfenpyrad, bifenthrin, acetamiprid were found in 55.6%, 33.3%, 18.9% and 16.7% of samples, respectively. Pesticide residues in Tieguanyin tea varied significantly over the seasons and across the production regions. Based on data obtained, the health risks associated with long-term exposure to those pesticides were assessed and risks of detected pesticides were ranked. The hazard quotients (HQs) among the detected pesticides range from 5 × 10⁻⁸ for fenpropathrin to 3 × 10⁻⁴ for imidacloprid. The results demonstrated that despite a high occurrence of pesticide residues in Tieguanyin tea, residue levels observed could not be considered as a serious public health problem. The risk ranking scheme showed dicofol and thiacloprid were considered to pose a medium-risk. The suggestions for 17 detected pesticides used in Tieguanyin tea plantation were made, including those already banned from use in China (dicofol and methomyl), recommended for diminished use (thiacloprid and chlorpyrifos), and permitted use with considering the pre-harvest interval (13 other pesticides).

Food and beverage consumption is the most possible route of human exposure to undesirable elements. Tieguanyin tea and white tea are widely-consumed beverage, which may be contaminated by fluoride (F), lead (Pb), chromium (Cr), and cadmium (Cd). For this study, the contamination levels and dietary exposure risks of these elements were studied from 72 Tieguanyin tea samples and 40 white tea samples from Fujian Province, China. The average concentrations of these elements decreased in order from F, Pb, Cr to Cd in Tieguanyin tea, while white tea in order from F, Cr, Pb to Cd. Metal-to-metal correlation indicated a weak positive correlation between Pb/Cd pairs (Tieguanyin tea) and Pb/Cr pairs (white tea). A weak negative correlation pair was found for Cr/Cd in Tieguanyin tea. The hazard index levels were below one, suggesting that there was no significant non-carcinogenic health risk to tea drinking consumers under the current dietary intake. The total cancer risk values of Pb, Cd, and Cr via the consumption of Tieguanyin tea and white tea were 4.01×10-5 and 7.64×10-6, fell into the acceptable range of 10-6~10-4. It demonstrated that the cancer risk for consumers via drinking Tieguanyin tea and white tea was acceptable.

To assess the dietary exposure risks of pesticide residues in snow fungus for the general population and young children, 91 snow fungus samples were collected from major production areas in Fujian Province, China and the presence of 44 pesticides was determined. A total of thirteen pesticides were detected; 65.9% of the samples contained one or more pesticide residues. The most frequently found pesticide was carbofuran, followed by acetamiprid and then imidacloprid. Data obtained were used for chronic, acute, and chronic cumulative dietary exposure risk assessments. The chronic hazard quotient (cHQ) was extremely low for both the general population and young children. The %ADI values of cumulative dietary exposures to organophosphorus pesticides and carbamates ranged from 0.53% to 1.49%, and did not exceed their corresponding ADIs. However, the acute dietary risks from all 13 pesticides, especially carbofuran and methamidophos, were of concern due to the relatively high acute hazard quotient. The risk ranking scheme showed that carbofuran could pose a high risk to snow fungus consumers. Finally, suggestions are made about the potential use in snow fungus cultivation of the pesticides with detected residues.