Environmental pollution has become one of the greatest problems in the world, and the concerns about environmental pollutants released by human activities from agriculture and industrial production have been continuously increasing. Although intense efforts have been made to understand the health effects of environmental pollutants, most studies have only focused on direct toxic effects and failed to simultaneously evaluate the long-term adaptive, compensatory and secondary impacts on health. Burgeoning evidence suggests that environmental pollutants may directly or indirectly give rise to disordered element homeostasis, such as for iron. It is crucially important to maintain concerted cellular and systemic iron metabolism. Otherwise, disordered iron metabolism would lead to cytotoxicity and increased risk for various diseases, including cancers. Thus, study on the effects of environmental pollutants upon iron homeostasis is urgently needed. In this review, we recapitulate the available findings on the direct or indirect impacts of environmental pollutants, including persistent organic pollutants（POPs）, heavy metals and pesticides, on iron homeostasis and associated adverse health problems. In view of the unanswered questions, more efforts are warranted to investigate the disruptive effects of environmental pollutants on iron homeostasis and consequent toxicities.
Graphene oxide（GO）displays promising properties for biomedical applications including drug delivery and cancer therapeutics.However,GO exposure also raises safety concerns such as potential side effects on health.Here,the biological effects of GO suspended in phosphate buffered saline（PBS）with or without 1% nonionic surfactant Tween 80 were investigated.Based on the ex vivo experiments,Tween 80 significantly affected the interaction between GO and peripheral blood from mice.GO suspension in PBS tended to provoke the aggregation of diluted blood cells,which could be prevented by the addition of Tween 80.After intravenous administration,GO suspension with or without 1% Tween 80 was quickly eliminated by the mononuclear phagocyte system.Nevertheless,GO suspension without Tween 80 showed greater accumulation in lungs than that containing 1% Tween 80.In contrast,less GO was found in livers for GO suspension compared to Tween 80 assisted GO suspension.Organs including hearts,livers,lungs,spleens,kidneys,brains,and testes did not reveal histological alterations.The indexes of peripheral blood showed no change upon GO exposure.Our results together demonstrated that Tween 80 could greatly alter GO＇s biological performance and determine the pattern of its biodistribution in mice.
