The Respiratory Deposition Rates Of Typical Volatile Organic Compounds To The Human Beings Via Inhalation And Related Health Risks

Harmful volatile organic compounds（VOCs）emitted to the environment are mainly deposited in the human respiratory system through respiratory exposure,and seriously threaten human health.Traditionally,the health risk assessment was evaluated by using the standard model based on the exposure time and exposure concentration.Nevertheless,the VOCs are partly deposited in human body and damage to the human health.Therefore,by applying the respiratory deposition rate of VOCs to the respiratory exposure risk assessment is more accurate.Factors such as environmental concentration and physicochemical properties of VOCs affect the respiratory deposition rate of VOCs,but the impact of physiological factors on the deposition rate of inhaled VOCs remains to be explored.To solve the above-mentioned problems,a total of 120 healthy volunteers（Female:Male=5:7）elected as non-exposed people were recruited to find the relationship between human physiological parameters and the deposition rates of the selected VOCs.Furthermore,another 120 people from a town in the e-waste dismantling area were recruited as exposed people.The concentration of volatile organic compounds inhaled and exhaled by the human body from Proton transfer time-of-flight mass spectrometry（PTR-TOF-MS）were used to calculate the deposition rate of VOCs in the human respiratory system.We also used the Spirometer to measure the lung function factors of the human body.We had compared and analyzed and exposed people,the lung function factors of exposed and non-exposed people,and the composition and concentration of exhaled volatile organic compounds from non-exposed people assessed the health risks of respiratory exposure of VOCs.The main conclusions of this study are as follows:（1）In order to explore the effect of breathing method on the deposition rate of volatile organic compounds inhaled by the human body,an exhaled gas collection device was manufactured.The main body of the device is composed of a buffer air bag and a heating box.External three-way valves were used to control sample injection and bag flushing.Disposable mouthpieces and masks were applicable to explore the effect of breathing methods.（2）Two healthy male and two female volunteers were recruited to measure the deposition rates of VOCs successively with nasal-in-nasal-out,oral-in-nasal-out,and oral-in-oral-out before and after three meals in three days.Comparing the significant differences of the selected volatile organic deposition rates of the 3 methods and 6sampling times,the results showed that the breathing methods and sampling times did not affect the deposition rates of VOCs.Further,120 healthy volunteers were recruited to measure the profiles of exhaled gas.The inhaled and exhaled concentrations of CH₂O,CH₅N,C₂H₆O,C₂H₄O₂,C₃H₈O,C₆H₆,C₇H₈,C₈H₈,and C₈H₁₀were measured the composition and concentration of exhaled VOCs through nose-in-oral-out.We also compared the differences in the sex,age and body mass index（BMI）of the deposition rate of VOCs from 120 unexposed people.The results showed that the deposition and inhalation concentrations of CH₂O,CH₅N,C₂H₆O,C₂H₄O₂,C₃H₈O,C₆H₆,C₇H₈,C₈H₈,and C₈H₁₀of 120 healthy volunteers fit linear regression.In addition,no gender and body mass index difference were observed in deposition rates,except age affecting CH₂O,CH₅N and C₂H₄O₂.Lung function parameters were positively correlated with the deposition rates of CH₂O,CH₅N,C₂H₆O and C₈H₁₀.（3）What’s more,120 exposed volunteers were recruited from a town in the e-waste dismantling area,and we analyze the respiratory deposition rates of 35 kinds of VOCs.Compared with non-exposed people,6 kinds of volatile organic compounds include:C₂H₄O₂,C₃H₈O,C₆H₆,C₇H₈,C₈H₈and C₈H₁₀were deposited in the respiratory system from the past of e-waste dismantling environment and exhaled in the office Comparative analysis of the routine lung function factors of 43 exposed area subjects and 120 non-exposed area subjects,the FEV1,FVC,MMEF,MVV and VT of the exposed area subjects were lower than that of the non-exposed population,indicating that after long-term VOCs respiratory exposure,lung function of the exposed area population has been reduced to a certain extent.Above all,this study explored the deposition rates of volatile organic compounds were affected by the breathing methods,age and conventional lung function parameters.Therefore,due to individual differences,it is more scientific and accurate to actually use respiratory deposition rate in human breath exposure risk assessment.After being exposed to the occupational environment,the lung function decreased and the concentration of exhaled gas components changed as compared with the non-exposed population.Exploring the relationship between respiratory exposure,lung function damage and the changes of the concentration of exhaled VOCs might promote the establishment of human health protection early warning.The results indicated that VOCs respiratory exposure threatens human health,and we should adopt cleaner production activities.