Heavy Metal(loid) Accumulation in the Ovarian Tissue of Free-Ranging Queens and Bitches Inhabiting Highly Polluted Urban Environments

SIMPLE SUMMARY: Animals are sensitive indicators of environmental pollution and human exposure to environmental contaminants, especially heavy metal(loid)s which have adverse effects at very low concentrations. Cats and dogs meet the demands that define a good sentinel species as they share the human environment and their lifespan is long enough to show the effects of exposure over time. We studied the level of essential and non-essential heavy metal(loid)s in the ovaries of free-ranging queens and bitches of different ages inhabiting highly polluted and non-polluted urban areas of the island of Sardinia, Italy. Our main results revealed an increase in non-essential metals (i.e., cadmium and lead) in the ovarian tissue of animals living in the contaminated sites and an age-related bioaccumulation of these metals. These findings indicated that the accumulation of heavy metal(loid)s in feline and canine ovaries reflected the quality of the inhabited environment and provided new insights for the use of companion animals as sentinels to study female reproductive toxicity of environmental pollution by these chemicals in humans and animals. ABSTRACT: There is strong scientific evidence that exposure to environmental contaminants, such as heavy metal(loid)s (HMs), can impair female reproductive function. Pets, such as cats and dogs, who share the same habitat as humans, may be particularly useful sentinel models for detecting HMs in the ovary. In the present study, we compared the concentration of essential (Ems; Cu, Fe, Mn, Se, and Zn) and non-essential metal(loid)s (NEMs; Al, As, Cd, and Pb) in the ovarian tissues of free-ranging queens and bitches of different ages living in industrialized/highly polluted (south group) and non-polluted (north group) urban areas of the island of Sardinia, Italy. The results showed that both EMs and NEMs were present at detectable concentrations in feline and canine ovaries and their levels varied according to geographical areas and animal age. Among the EMs, Cu was found elevated in older queens and bitches inhabiting the southern area. Cadmium and lead were higher in feline and canine ovaries of older animals from the south compared to those living in the north. In addition, Cd and Pb concentrations increased in individuals of both species living in the south. These findings showed new perspectives for the use of pets as early warning sentinels of environmental pollution by HMs and for the risk of human exposure within a “One Health” approach. Pets may help to study the link between exposure to metals and female reproductive disturbances in mammals.