Breath analysis: technical developments and challenges in the monitoring of human exposure to volatile organic compounds

• Monitoring of human exposure to VOCs has become an increasingly urgent need as the result of human’s growing concern about human quality of life.
• Breath analysis, as a tool of biomonitoring, has enormous potential in assessment of human exposure to large numbers of VOCs.
• A brief review of the frequently used methods for breath analysis in both direct and in-direct measurements is presented, and some promising new techniques are specially highlighted.
• Both occupational and non-occupational exposure assessed by breath analysis are reviewed in this paper, resulting with the proposal of equal attention to both categories of environmental exposure assessment.
• Challenges and obstacles in theoretical knowledge and practical application of human breath analysis are also proposed in this paper.

At present, there is a growing concern about human quality of life. In particular, there is an awareness of the impact of volatile organic compounds (VOCs) on the environment and human health, so the monitoring of human exposure to VOCs is an increasingly urgent need. Biomonitoring is theoretically more accurate compared with traditional ambient air monitoring, and it plays an essential role in human environmental exposure assessment. Breath analysis is a biomonitoring method with many advantages, which is applicable to assessments of human exposure to a large number of VOCs. Techniques are being developed to improve the sensitivity and precision of breath analysis based on in-direct and direct measurements which will be reviewed in this paper. This paper briefly reviews the frequently used methods in both of these categories, specifically highlighting some promising new techniques. Furthermore, this review also provides theoretical background knowledge about the use of breath analysis as a biomonitoring tool for human exposure assessment. A review of the application of breath analysis to human exposure monitoring during last two decades is also provided according to occupational/non-occupational exposure. Obstacles and potential challenges in this field are also summarized. Based on the gradual improvements in the theoretical basis and technology reviewed in this paper, breath analysis is an enormous potential approach for the monitoring of human exposure to VOCs.