The origin, effects and control of air pollution in laboratories used for human embryo culture

Testing shows that most laboratories conducting human gamete and embryo culture have air quality and sources of contamination that exceed the levels measured in homes, businesses and schools. The sources of these contaminants have been shown to be either from activities outside the laboratory, or emitted from materials used in the facility, such as compressed gas, cleaning and sterilizing agents, plastic and stored materials. Both the laboratory structure and the air handling systems may affect the air composition. The significance of these findings is being validated by the accumulation of field case studies and now by assay procedures. Products given off by road sealant were shown to have accumulated in one of the examined laboratories, adjacent to a large re-surfaced parking area. Aldehydes such as acrolein, hexanal, decanal, pentanal and others were detected at elevated concentrations that were statistically significant. Since it is not appropriate to add potentially suspect chemicals to human embryos, we used a mouse-model to study the effect of acrolein. The growth of mouse embryos was significantly affected after acrolein was added at different concentrations to the culture environment. The physiological effect was noted at concentrations in the low ppm range. The testing end-point of embryo death must still be considered to be a crude basis for evaluating toxicological effects, since it involves addition of compounds to culture media and unprotected growth until the blastocyst stage. The findings may, however, support observations of decreased pregnancy rate following exposure of human embryos to aldehydes or other adverse conditions. With proper engineering and material selection, it is possible to reduce such contamination. The usefulness of this approach for controlling aldehydes has been demonstrated by decreasing levels in the laboratory to below those of the outside air.