Health effects of certain volatile organic compounds (VOCs) on animals and humans are well established in toxicology literature. However, levels of airborne contaminants that are safe for adults and mature animals (a few micrograms per cubic metre) appear to be toxic at the cellular level. Below are summaries of several investigations that examine the relationship between airborne molecular contaminants in IVF laboratories, the viability of the cell cultures, and successful assisted reproduction efforts.
1) Cohen, J. et. al., “Opinion: Ambient Air and its potential effects on conception in-vitro”, Hum. Reprod., (12) 1742-1749, 1997.
This early discussion explored the potential impact of various indoor sources of VOCs in IVF laboratory air. The authors noted that traditional toxicological investigations focused on differentiated organisms, which are to some degree protected by their immune, digestive and epithelial systems. Few if any studies applied to oocytes or free-living embryos, where passive and active absorption mechanisms are indiscriminate. Sources of airborne molecular contaminants in IVF laboratory air cited included trace contaminants in compressed air and bottled gases; outgassing from incubators, plastic Petri dishes, and labware; sorption, partitioning and desorption from ordinary fluids in the laboratory (e.g. water, mineral oil); outgassing from medical and electronic equipment; cleaning products, floor waxes and disinfectants; anaesthetic gases; air conditioning refrigerants; building materials of construction, carpet and paint. Outdoor sources of airborne pollutants include vehicular and industrial emissions, incineration and seasonal crop burning. A number of specific VOCs and airborne molecular compounds were assayed and identified in the laboratory air.
Note: The preceding article and other related information may be retrieved at: www.ivfonline.com/User/Newsstand/research.aspx
In this first of several papers, relationships were sought between particulate and organic vapour levels, and preimplantation embryogenesis and rates of implantation. The authors selected two independent, certified companies to collect and analyze air samples in clinical and laboratory areas. Independent observers evaluated all procedures performed in the facility, including fertilization rates, zygote and embryo morphology and implantation rates. The authors then employed a retrospective experimental design to explore the role that measured ambient air constituents exerted on preimplantation toxicology over a twelve-month study period.
The researchers found that all areas within the IVF laboratory and accompanying procedure rooms met NEBB requirements for a Class 100 clean room. However, implantation rates were significantly lower during the three-month test quarter (TQ3) corresponding to a detectable, ~2 ppb level of toluene in most of the facility. In the following quarter, toluene levels declined below detectable limits (~0.1 ppb) and implantation rates returned to levels similar to the first two quarters.
3) Worrilow, K.C., Huynh, et. al., ”A retrospective analysis: Seasonal decline in implantation rates and its correlation with increased levels of volatile organic compounds.”, Fertility and Sterility, (78), Suppl. 1., p. S-39, abstract #O-101, September 2002.
In the following year, the authors reported that their continued retrospective analysis of 26 months of operation had detected a potential seasonal relationship between periods of elevated outside temperature and high relative humidity, and elevated levels of the volatile organic compound toluene. They reported that a second quarterly period (TQ8) had exhibited slightly elevated toluene levels (inside and outside) along with a corresponding decrease in implantation rates. During the following quarter, outside temperature, humidity and toluene levels all declined, and corresponding implantation rates again returned to ‘normal’ levels. The authors hypothesized that the summertime seasonal elevation in outside temperature and humidity might have initiated desorption of trapped VOCs from the carbon filters installed in the laboratory air handling system, as well as reduced the system's adsorption efficiency level.
4) A third research paper in this series, presented in autumn 2004, reports on improvements to IVF laboratory operation that resulted in a dramatic increase in clinical pregnancy rates. Please check back for a summary of this paper after its publication later in 2005.
Note: The research in the studies cited above was conducted at the ultra-clean lab facility located at the Lehigh Valley Hospital & Health Network in Muhlenberg, Pennsylvania, USA. Clean, contaminant-free air in this lab is one of the key factors cited by the fertility experts at the facility for its higher success rates for pregnancies and healthy babies compared to traditional IVF facilities.