Children’s Environmental Health and Genotoxicity. Peter D. Sly, TVW Telethon Institute for Child Health Research and César Paz-y-Miño, Catholic University of Ecuador chaired an interesting session with presentations on children’s environmental health and genotoxicity that included presentations from researchers from China, Ecuador, Mexico, India and Australia. Peter Sly started proceedings with an overview of children’s susceptibility to environmental pollutants. This presentation highlighted the reasons why children can not be considered as little adults and why they generally receive a higher dose of pollutant for a given exposure. The concepts of “developmental stage susceptibility” leading to “windows of susceptibility” were discussed. In essence, the developmental stage during which an exposure occurs is a major determinant of the consequences of that exposure. The three organ systems that are most vulnerable from exposure to adverse environments are the respiratory, immune and central nervous systems as these are immature at birth and have prolonged postnatal periods of growth and development. Dr. Li Hong, from China gave a review of the environmental risk factors that have been associated with childhood asthma in many parts of the world. The evidence linking exposure to various environmental agents, including bioaerosols, environmental tobacco smoke, NO 2, and volatile organic compounds, especially benzene, toluene and formaldehyde was discussed. Dr. Li concluded that while solid epidemiological data linked environmental exposures to childhood asthma actual exposure data and mechanistic studies were lacking.Dr. Paz-y-Miño spoke about monitoring DNA damage in exposed individuals to petroleum hydrocarbon in Ecuador. After reviewing the malignant and non-malignant health effects associated with exposure to petroleum hydrocarbons, he explained the methods used to detect DNA damage including the “comet” assay and assessment of DNA breaks and fragmentation. Data obtained from petroleum workers and control in Ecuador showed substantial evidence of DNA damage in those exposed to hydrocarbons. The level of damage was much higher in workers who have a specific mutation in the MSH2 gene. These data demonstrate the importance of genetic susceptibility to understanding the health outcomes from environmental exposures. Dr. T. Chakrabarti from the National Environmental Engineering Research Institute, India, presented a paper titled “Identification of biomarker 1-hydroxypryene (1-OHP) and its correlation with genetic polymorphism of diesel exposed Indian population”. He described a survey of workers with occupational exposure to PAH and the use of 1-OHP as a biomarker of exposure. The levels of 1-OHP were related to exposure to diesel exposure and did not appear to be modified by other factors including cigarette smoking, age, or alcohol consumption. Levels were significantly higher in workers with the GSTM1 null genotype when compared to those with the GSTM1 wild-type genotype. These data demonstrate the important interaction between genetic susceptibility and environmental exposure. An understanding of the pathways involved in metabolising xenobiotics and in host defenses are important in studies of exposed populations. Dr. Hailin Wang gave a presentation titled “Identification and analysis of stereoisomeric DNA adducts”. He discussed the potential of benzene[o]pyrene to cause DNA damage and of HPLC techniques available for detecting DNA adducts. He discussed the various steps necessary in the processing of samples and of identifying DNA adducts and demonstrated the validity of the methods. Dr. Lizbeth Lopez Carrillo presented her research on the effects of dichlorodiphenyldichloroethylene (ppDDE) exposure during the first trimester of pregnancy alters the anal position in male infants. This metabolite of DDT has anti-androgenic properties and is known to alter sexual differentiation in male rats. The anogential distance at birth is used as an indication of prenatal androgenic status in rats. In this study, conducted in a birth cohort in Mexico, the androgenital distance was affected in male but not female infants who were exposed to ppDDE in the first trimester. Data showing the effect of endocrine disrupter chemicals on humans are sparse. This study provides importance evidence that the data from the animal kingdom are likely to be relevant to humans. The final presentation in the session was given by Dr. Bro Sheffield-brotherton from the National Toxics Network, an Australian NGO. He spoke about intergenerational equity, in particular the responsibility current generations have towards future children and how this was being abrogated with the current lack of regulation of toxic chemicals. He commented on the introduction of approximately 80,000 new synthetic chemicals and 1500 new chemicals each year. In general these were not tested for impact on children and developing fetuses, left residues in food, contributed to indoor and outdoor pollution and contaminated house dust. He presented the regulatory situation in various countries and concluded by calling for increased training and awareness of the problem for medical professionals, establishment of registers of new chemical and for adequate monitoring after their introduction.