Impaired reproduction

Cladoceran, D. magna 1.0 Reduced survival and impaired reproduction in 15 days 14... 

Sublethal effects included testicular damage in rats after drinking water containing 2.2 to 20.0 mg 1080/L for 7 days (0.07 to 0.71 mg/kg BW daily), impaired reproduction in mink fed diets containing 0.8 mg 1080/kg ration for 60 days, and altered blood chemistry in ferrets given diets containing 1.1 mg 1080/kg ration for 28 days. 

Selenomethionine group had altered immune function, altered serum enzyme activities, and elevated concentrations of selenium in liver (4 times control values) and breast muscle (14 times). Sodium selenite-treated birds had normal immune function and selenium tissue burdens however, serum enzyme activity was disrupted in the 3.5 mg/L group Adults normal. Impaired reproduction (reduced survival of ducklings, increased developmental abnormalities) for selenomethionine occurs between 4 and 8 mg/kg ration selenocysteine did not impair reproduction at 16 mg Se/kg ration... 

Heinz, G.H., D.J. Hoffman, and L.G. Gold. 1989. Impaired reproduction of mallards fed an organic form of selenium. Jour. Wildl. Manage. 53 418-428. 

Jensen, L.S. 1968. Selenium deficiency and impaired reproduction in Japanese quail. Proc. Soc. Exp. Biol. Med. 128 970-972. 

Saiki, M.K. and R.S. Ogle. 1995. Evidence of impaired reproduction by western mosquitofish inhabiting seleniferous agricultural drainwater. Trans. Amer. Fish. Soc. 124 578-587. 

Despite extensive investigation of pregnancy block since its discovery, a convincing explanation for its functional significance and evolutionary development has remained elusive. The postponement of reproduction inevitably impairs reproductive success, but in order to evolve the Bruce effect must offer an overall benefit. The costs and benefits may be very different for males and females. 

The information available on UV-susceptibility of different developmental stages in kelps indicate the unicellular zoospores as being most sensitive (Wiencke et al. 2000, 2004). However, zoospore UV-sensitivity varies species-specifically as a function of depth distribution of the sporophyte, i.e. kelps from shallow water are more tolerant than plants from deeper vertical positions. Consequently, any increase in UVB-induced spore mortality will result in impaired reproductive success and finally reduce fitness of the population. In addition, elevated UVB will penetrate deeper into the water column, which may result in a shift of the upper distribution limit of seaweed communities to deeper waters (Wiencke et al. 2006). 

So far the toxicologist has not made inquiries regarding a number of potentially important questions. Can the chemical harm a developing embryo and fetus, perhaps producing birth defects Can the chemical reduce male or female fertility, or otherwise impair reproduction Can... 

Wekesa, K. S. and Lepri, J. J. (1992). Removal of the vomeronasal organ impairs reproduction in male prairie voles. Chemical Senses 17,718. 

Developmental toxicity and impaired reproductive capacity were seen in two oral studies in mice. " The lowest observed adverse effect level was lOmg/l /day from day 7 to day 16 of gestation."... 

A mild degree of spermatogenic suppression and impaired reproductive performance was reported in a follow-up study of eight men accidentally exposed to bromine vapor. The men were exposed between 50 and 240 minutes to unknown concentrations after a spill. Clinical manifestations including respiratory distress and chemical skin burns were noted at the time of the incident. Because of the small number in the cohort, a confident cause-result linkage cannot be established for bromine exposure and reproductive effects. 

Chemicals such as l,2-dibromo-3-chloropropane can disrupt spermatogenesis, leading to impaired reproductive function, including sterility. Men and women undergoing cancer chemotherapy with alkylating drugs are at increased risk for sterility. 

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