By Keith Nuthall
Plastics and Rubber Weekly
Nairobi -- The United Nations Environment Programme (UNEP) has called for global action to tackle the growing problem of plastics pollution in the world's seas and oceans. Its 2011 yearbook highlights "persistent, bio-accumulating and toxic substances" associated with plastic marine waste as "a new and emerging concern."
The problem is partly about scale: in North America and Western Europe each person now uses around 100 kilograms of plastic materials annually, projected to rise to 140 kg by 2015. And Asian emerging market countries now use around 20 kg of plastic per year, growing to 36 kg by 2015.
A significant proportion is waste, much ending up in seas and oceans, often shredded into small particles, according to Nairobi-based UNEP.
And then another problem arises - these materials absorb other pollutants and are then consumed by wildlife. The UNEP report claimed research indicates these plastic fragments become contaminated with dissolved chemical pollution, such as polychlorinated biphenols (PCBs) and the pesticide DDT, via polluted seawater and sludge. "Many of these pollutants including PCBs cause chronic effects such as endocrine disruption, mutagenicity and carcinogenicity," reported the year book.
"Some scientists are concerned that these persistent contaminants could eventually end up in the food chain," it added. The concern arises from conclusions that species such as swordfish and seals - at the top of the food chain - are potentially vulnerable, and of course consumed by humans.
The year book calls for robust coordinated action, listing some ongoing initiatives, for instance international treaties such as the UN's International Convention for the Prevention of Pollution from Ships and UNEP's Global Programme of Action for the Protection of the Marine Environment from Land-based Activities.
UNEP calls for better enforcement of such rules, the development of consumer awareness plastic disposal and improved support for national and community-based initiatives on effective waste disposal, especially recycling.