[Image credit: minthu]
Over the last 200 years, the global population has been growing at an exponential rate and according to the UN, is predicted to reach 8.5 billion by 2030. The population increase to date, has been supported by the development of agricultural, industrial and health care resources, which has led to the rise in the production and use of a variety of different chemicals. In recent years, many of the substances, either used in or created by these industries have been named as “emerging contaminants” (EC’s). Until very recently, the main focus of the impacts that chemicals cause in the environment was mainly attributed to heavy metals, active ingredients traditionally used in pesticides and persistent organic pollutants. However, concern has been growing over the environmental and health risks of EC’s. Many EC’s are considered to be water pollutants, yet they remain largely unregulated by current water-quality standards. So what are these chemicals and why are they a problem?
Latest figures show that global production of plastic has risen to 280 million tons per year, with much of this entering the seas and oceans via ships, offshore platforms and fishing, coastal littering and sewage-related debris from rivers and storm drains. UNEP estimates that between 6.4 – 8 million tons of litter ends up in the oceans. The properties that make plastic useful, such as its resilience to degradation, can make it problematic once it is no longer needed. A pair of studies from Plymouth University and Exeter University, investigated whether micron-sized pieces of plastic (as a result of weathering) that sink into mud or sand, are causing harm to species at the base of the food chain, that ingest this sediment during feeding. Both papers are presented in the journal Current Biology.
According to researchers from Dartmouth College, New Hampshire, rising sea surface temperatures may increase the ability of the fish to accumulate mercury in their tissue. This could present a risk to the health of consumers of seafood due to the bioaccumulation of methylmercury and transfer between marine food webs. The paper is published in the journal PLOS ONE.