Humans in industrialized societies are continuously exposed to a plethora of environmentalchemicals, of which the long-term consequences are largely unknown. Reduced fertility couldbe one such undesired consequence, and indeed reduced sperm quality is increasinglyreported from many developed countries. Many environmental chemicals induce DNAdamage, and sperm DNA damage is associated with reduced sperm quality, disturbed embryodevelopment and early abortions. The present work was aimed at establishing a method todetect sperm DNA damage and to elucidate its impact on fertilization and early embryodevelopment. Specifically we chose to study the widely distributed genotoxic benzo(a)pyrene(B(a)P) and glycidamide (GA; a metabolite of acrylamide), that most of us are exposed to ona daily basis. Determination of sperm DNA damage is a major challenge and at present thereare no established protocols available. A less explored strategy is to assess DNA damage bythe polymerase chain reaction (PCR). The easily accessible mitochondrial genome is moresusceptible to DNA damage than the nuclear genome and thus represents a more sensitivetarget for the identification of sperm DNA damage. The PCR strategy involves a longamplicon (10 kb) for the determination of DNA damage relative to template numberdetermined by a short fragment PCR assay (117 bp), the mitochondrial DNA damage assay(MDDA). The underlying concept is that DNA lesions will inhibit the DNA polymerasewhich is utilized in the long PCR assay to detect DNA damage: less PCR product equates tomore DNA damage. The short PCR also reveals changes in mitochondrial genome numbers.The optimization of the method included determination of suitable DNA isolation andquantification procedures, along with appropriate PCR conditions, subsequently tested in cellsexposed in vitro and frozen mouse tissue samples. Sperm and liver were harvested from miceexposed to B(a)P or GA a few days prior to sacrifice. The level of DNA damage in sperm andin liver was assessed by the MDDA. In parallel the sperm was used for in vitro fertilizationexperiments to determine fertilization rate and early embryo development. The MDDAproved successful in liver samples although more extensive optimization is required in spermthan was permitted within the scope of this MSc-thesis. Exposure to both B(a)P and GA gaverise to reduced fertilization rates with no indications of disturbance of early embryonaldevelopment at the doses used. In conclusion the MDDA is a promising tool for measuringDNA damage, and warrants further optimization for use in sperm. Moreover we verify thatexposure to ubiquitous genotoxic agents influence fertilization.