Addressing the global challenge of coastal sewage pollution

Abstract

Coastal environments, essential for about half of the world's population living near coastlines, face severe threats from human-induced activities such as intensified urbanization, aggressive development, and particularly, coastal sewage pollution. This type of pollution, comprising untreated sewage discharging nutrients, pathogens, heavy metals, microplastics, and organic compounds, significantly endangers these ecosystems. The issue of sewage in coastal areas is complex, influenced by factors like inadequate sewage systems, septic tanks, industrial and agricultural runoff, and natural processes like coastal erosion, further complicated by oceanic dynamics like tides and currents. A global statistic reveals that over 80 % of sewage enters the environment without treatment, contributing significantly to nitrogen pollution in coastal ecosystems. This pollution not only harms marine life and ecosystems through chemical contaminants and eutrophication, leading to hypoxic zones and biodiversity loss, but also affects human health through waterborne diseases and seafood contamination. Additionally, it has substantial economic repercussions, impacting tourism, recreation, and fisheries, and causing revenue and employment losses. Addressing this issue globally involves international agreements and national legislations, but their effectiveness is hindered by infrastructural disparities, particularly in developing countries. Thus, effective management requires a comprehensive approach including advanced treatment technologies, stringent regulations, regular monitoring, and international cooperation. The international scientific community plays a crucial role in fostering a collaborative and equitable response to this pressing environmental challenge.