The dog as a sentinel species for environmental effects on human fertility.

Rebecca Nicole Sumner,Richard Graham Lea,Morne Van Der Mescht,Andrew Byers,Gary Crane William England,Imogen Thea Harris

doi:10.1530/rep-20-0042

Rebecca Nicole Sumner, Richard Graham Lea + Show 4 more

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https://doi.org/10.1530/rep-20-0042

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Abstract

Despite the vast body of evidence that environmental toxicants adversely affect reproductive development and function across species, demonstrating true cause and effect in the human remains a challenge. Human meta-analytical data, showing a temporal decline in male sperm quality, are paralleled by a single laboratory study showing a similar 26-year decline in the dog, which shares the same environment. These data are indicative of a common cause. Environmental chemicals (ECs) detected in reproductive tissues and fluids induce similar, short term, adverse effects on human and dog sperm. Both pre- and post-natal stages of early life development are sensitive to chemical exposures and such changes could potentially cause long term effects in the adult. The environmental 'pollutome' (mixtures of ECs) is determined by industrialisation, atmospheric deposition and bioaccumulation and characterises real-life exposure. In Arctic ecosystems, dietary and non-dietary chemical contaminants are detectable in biological tissues and linked with adverse health effects in both dogs and their handlers. In the female, such exposure could contribute to disorders such as ovarian insufficiency, dysregulated follicle development, ovarian cancer, and polycystic ovarian syndrome. In the dog, ovarian chemical concentrations are greater in the testis. In addition, preliminary studies indicate that dietary exposures may influence the sex ratio in the offspring in favour of females. Within this article, we review current knowledge on chemical effects on human reproduction and suggest that the dog, as a sentinel species for such effects, is an essential tool for addressing critical data gaps in this field.

Highlights

In the early twentieth century, coal miners exploited the enhanced sensitivity of the canary as an early warning system to carbon monoxide
To asses industrially associated contaminants, ants have been proposed as a valuable bio-monitoring species for environmental contamination and the chemical profiling of differing geographical regions due to the abundance of ant populations on a global scale (Wania 2003). While research in this area has the ability to advance understanding in specific Environmental chemicals (ECs) profiles and potentially predict the subsequent interactions of ECs within humans, there is a distinct need for a sentinel that closely shares our environment. It is for these reasons that we propose the dog as a sentinel species for better assessing human exposure to ECs
There is an overwhelming body of evidence to suggest that both male and female reproductive health is being adversely affected through exposure to mixtures of environmental contaminants

Summary

Introduction

In the early twentieth century, coal miners exploited the enhanced sensitivity of the canary as an early warning system to carbon monoxide. The dog as a sentinel for human environmental chemical exposure

Results

Conclusion