Showing posts with label Environment - Pollution and Contamination. Show all posts
Showing posts with label Environment - Pollution and Contamination. Show all posts

Wednesday 15 November 2023

PFAS chemicals - a world wide contamination

Contamination of both the general environment and the human population from chemicals has long been a deep concern and for the most part, the issue has been one that can be controlled with the ''its-not-too-late" ethos. For this issue however, that ethos cannot apply.

The US Centers for Disease Control (CDC) provides the basic understanding of the scale of the problem that is now an irreversible contamination of world-wide significance. 

The CDC states " The per-and polyfluoroalkyl substances (PFAS) are a group of chemicals used to make fluoropolymer coatings and products that resist heat, oil, stains, grease and water. Fluoropolymer coatings can be in a variery of products. These include clothing, furniture, adhesives, food packaging, heat-resistant non-stick cooking surfaces, and the insulation of electrical wire. Many PFAS, including  perfluorooctanoic sulfonic acid  (PFOS) and perfluorooctanoic acid (PFOA), are a concern  because they:

  • do not break down in the environment
  • can move through soils and contaminate drinking water
  • build up (bioaccumulate) in fish and wildlife
PFAS are found in rivers and lakes and in many types of animals on land and water"

A fact sheet can be obtained at this link: CDC biomonitoring PFAS Fact Sheet

A Bloomberg video explains the issue further -

Sunday 10 November 2013

Genetically Modified Wheat - escaping into the wild

The use of genetically modified (GM) crops particularly wheat is a highly controversial topic and GM crops are currently strictly controlled at point of origin and GM wheat is not approved for commercial use anywhere in the world. Despite exacting controls however GM wheat does escape from test farms and has been shown to actually be capable of replacing natural grown wheat where the two come into contact. Agricultural biotech giant Monsanto has been the main operator, researcher and developer of GM crops but has been at a loss to explain GM wheat materialising in non research locations such as the farm in Oregon this year. The original GM wheat test programme was ended in 2004 and the GM material was destroyed yet this farm was found to have GM wheat 9 years later and was not even part of the actual GM test programme.

Similar experiences have been found with testing of GM crops in Australia where there is a high potential for cross contamination with natural wheat. Japan and South Korea immediately halted wheat imports from the United States until the wheat had been tested for GM traces. Australia would do well to remain cautious about the use of GM crops given the almost non-existent information on downstream impact and longer term human health. 

Sunday 12 May 2013

Hitching a ride - compromising the earth's waterways and ocean ecosystems

Container ship in port
The movement of ocean and water organisms around the globe as a result of hitching a ride on the ships traversing the seas is not a new problem nor is it one which the general public have not heard about. However the scale, extent and failure to act when solutions actually exist, is almost certainly a fact which is not so well known. Cargo ships and tankers require ballast water to avoid capsizing mainly when offloading cargo but also when carrying lighter loads - the water is up taken in one port and often discharged in another port, thousands of kilometres away. A large ship can carry up to 60,000 tonnes of ballast and more than 7 billion tonnes of ballast water is transported around the world each year in which an estimated 7,000 different species of seeds spores, plankton, bacteria, eggs and larvae hitch a ride into new surroundings. The impacts can be dramatic with examples being the European zebra mussel arriving in the Great lakes of North America, Chinese mitten crabs in Europe, Asian Kelp in Southern Australia, Mediterranean mussels in Southern Africa and dinoflagellates spreading across the world (the sources of 'red tides'). The Mediterranean has 900 alien species which originated from ballast water.

Efforts have been made to reach an international agreement through the UN Convention on Ballast Water in 2004 which requires ships to install kits to eliminate biological hitchers in their ballast water. The International Maritime Organisation has certified 20 commercial treatment systems which will do the task utilising various combinations of biocides, electrolysis, heat, ozone, irradiation or filtration systems. However for the treaty to come into effect, requires at least 30 nations representing 35% of the world's merchant shipping tonnage.  To date ratification nations only account for 29%  with the well known 'flags of convenience' countries - Panama, Bahamas, Malta and Cyprus - avoiding the issue. Nor have the US, UK, Germany, Italy and Japan ratified the treaty. The cost of taking no action is both economic as well as environmental for the invading species can cause significant negative impact - the Black Sea was devastated and its commercial fishing destroyed by the comb jellyfish  whilst the European zebra mussel blocked irrigation channels and water pipes in North America costing billions of dollars of restoration work. Inaction therefore is not really an option.

Sunday 21 October 2012

The sustainable world from Monsanto's view

Monsanto is arguably the world's largest multinational agricultural biotechnology company (but not agricultural company per se) with assets of $19.8 billion USD and the leader in genetically modified grain. It has an interesting history having previously been a chemical, polymers and plastics company and was transformed between 1997 and 2002 into the current entity. It still produces some pesticides but in its earlier incarnation, DDT and Agent Orange came from this company as well as PCBs for insulation. As a corporation it remains highly controversial and its development of GM products remains highly contested in the public domain.



Genetically Modified Food - the Greenpeace view

Genetically Modified (GM) Food - The perspective from Greenpeace - this short animation contains some of the accepted information on this issue but should be seen as one view on the debate as some explantations are contestable.



Genetically Modified Crops - The Upside Debate

Maize harvested
Any discussion involved genetically modified (GM) foods plus GM crops immediately triggers regular and consistent controversy with steadfast opposition from both environmentalists and some in the agriculture sector. However not all of the negative reaction is warranted and in a number of cases, the evidence against GM crops is flawed. In September 2012, the University of Caen, France reported that rats fed GM maize with an inbuilt resistence to the herbicide, glyphosate, were more susceptible to cancer. However subsequent analysis of the study has found that many of the control mice fed non GM maize also developed cancer. This month, the European Food Safety Authority concluded that the Caen study was of "insufficient scientific quality to be considered valid for risk assessment.."

An alternative set of data from the US National Agricultural Statistics Service has found that between 1996 and 2010, use of herbicides and insecticides with GM crops apparently declined by 9.1 % globally compared with non-GM crops. This is due to the fact that some GM crops have been engineered to be partly pest resistant and hence require less pesticides. Other GM crops produce sufficient pest resistant chemicals to not require spraying at all. This is a debate however which remains inconclusive and will continue for many years to come.

Saturday 23 April 2011

Ozone and rainfall - a new connection


Researchers, engineers and other scientists at Columbia University released the results of a study this month on the impact of the depletion of the ozone layer above Antarctica. The findings reflect an additioanl impact on the Earth from the damage to the ozone layer caused by human activity and the increased discharge of CFCs into the atmosphere. Most data gathered has, to date, focussed on the role of ozone in the reduction of harmful UV radiation from the Sun and consequently the increased UV exposure due to the 'hole' in this atmospheric layer. The new study used two independently drawn climate models - the Canadian Middle Atmosphere Model and the United States' National Centre for Atmospheric Research (NCAR) Community Atmosphere Model. In four experiments comparing data on sea ice, surface temperatures, precipitation and the ozone hole, the analysis showed the hole was the main driver of heavy summer rains across eastern Australia, the southwestern Indian Ocean and the Southern Pacific Convergence Zone.


Monday 22 November 2010

Silent Spring - has the lesson been learned?

It's now 48 years since Rachel Carson's 'Silent Spring' was published and marked a foundation point in defining the inherent risk of uncritical acceptance of  pesticides impact on the enivronment. Released by Houghton Mifflin on 27 September 1962,  the book itself is widely credited with helping launch the environmental movement and documented the detrimental effects of pesticides on the environment, particularly on birds. Carson who was a scientist, said that DDT had been found to cause thinner egg shells and result in reproductive problems and death. The chemical industry was criticised for spreading disinformation with public officials accepting industry claims uncritically.

Even with greater awareness, controls and regulation, high level risk continues. The Californian Condor, an endangered species, appears to be the next potential victim of contamination producing eggs with dangerously thin shells. A possible culprit is exposure to DDT through the food chain as condors feed off sea lions who in turn eat contaminated fish from an offshore dumping ground.
[New Scientist 20 November 2010]