Neonicotinoid pesticides (NPs) are neurotoxic substances. They are highly effective as insecticides owing to their water solubility, permeability, and long-lasting activity. These molecules are structurally similar to nicotine and act as nicotinic acetylcholine receptor agonists. The administration of NPs to experimental animals reportedly causes neuromuscular and reproductive disorders. Moreover, recently reported problems caused by NPs include damage to land-dwelling creatures (such as mammals and birds), hydrobiology, and ecosystems. This review summarizes the recent reports on NP concentrations detected in river systems in several Japanese regions. These values were lower than the environmental standard values; however, seasonal variations were observed. Furthermore, reports on NP-induced testicular and ovarian toxicity were examined, revealing that the mechanism of injury is mainly driven by oxidative stress. The use of NPs is declining worldwide, except in Japan; therefore, continuous monitoring remains necessary.

In recent years, the incidence of dental erosion caused by the ingestion of acidic foods and drinks, including sports drinks, has been increasing in Japan and elsewhere. Therefore, the problems associated with this injury can no longer be ignored in dental clinical practice. The ingestion of these foods and drinks is important from the viewpoint of overall health and disease prevention. For example, fermented foods, such as Japanese pickles, enhance the nutritional value of foodstuffs and promote the absorption of nutrients into the body, and sports drinks are useful for preventing heat stroke and dehydration. Therefore, eliminating these intakes is not a viable solution. In this paper, we outline the mechanism of dental erosion caused by acidic beverages and also describe the effectiveness of alkaline ionized water (AIW) at preventing acid erosion. Given the fact that the complete elimination of acidic beverage consumption is highly unlikely, remedies such as the use of alkaline ionized water (AIW) may be helpful.