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The Science

Croesus Projects Ltd. focuses its capabilities and competencies on four areas of environmental science. Under the leadership of the company’s chief scientist, Dr. Chris Anderson, Croesus has an international reputation for high-quality and innovative research and commercial work in each of these areas.

Part of the artisanal gold mining process
Artisanal & Small Scale Gold Mining

Gold mining can be organized and regulated, with mechanisms in place to protect workers and the environment.  But mining can also be informal and small-scale, with minimal regulatory control of activities.  This second form of mining is described as artisanal or small-scale gold mining (ASGM) and occurs throughout the developing countries of Asia, Africa and South America.  ASGM worldwide is associated with a range of environmental and social problems.

Croesus Projects Ltd. is actively involved in assessing the environmental impacts of ASGM on Lombok Island, Indonesia.  Together with the International Research Centre for the Management of Degraded and Mining Lands, Croesus is working to manage the environmental problems apparent at ASGM sites on Lombok in a socially and economically sustainable way.

Phytomining using sunflowers in Mexico
Precious Metal Phytomining

Phytomining is technology where plants are used to extract valuable metals from soil.  These metals are then recovered from the harvested plant material and sold to generate an economic profit.  Phytomining was first proposed for nickel in the 1990s.  Dr. Chris Anderson was instrumental in developing the idea of gold phytomining starting in 1998.

Precious metal phytomining is not yet a commercially viable activity.  But the idea has good potential as the world looks for greater environmental responsibility from the mining sector. Small-scale gold phytomining operations are well advanced in Indonesia and South/Central America, and Croesus scientists are involved with many of these operations.  The idea of palladium and platinum phytomining has also been proposed by a research consortium involving the University of British Columbia, Yale University and the University of York. Phytomining may be a novel pathway to synthesise precious-metal nano-particles that are catalytically active in a range of industrially-important chemical reactions.

Contamination due to artisanal gold mining in Indonesia
Contaminated Sites

Throughout the world, past and present land use has increased the concentration of inorganic elements and organic compounds in soil.  The concentration today can be above natural background levels and such land is defined as contaminated.  This contamination may have a detrimental effect on the plants, animals and microorganisms in the soil.  If this happens the land can be considered polluted.

Croesus has extensive experience in assessing the impact of historic and current-day practices on soil properties and processes.  Understanding this impact can define the level of environmental risk that may be apparent.  Where this risk is unacceptable, Croesus can assist in the design and implementation of management and remediation strategies.

Trace Element Nutrition

Trace element nutrients in our food such as iron, zinc and selenium come from the soil.  Plants accumulate trace elements as they grow, and these pass through the food chain.  But international data show that the trace element content of food is dropping with time.   Figures from the United States Department of Agriculture show a decline in the nutrient concentration of 43 crops tracked since the 1950s (1)​.  UK Government figures show similar statistics: declines of at least 10% of iron, zinc and selenium across a range of food crops since the 1950s (2).  What these figures imply is that we need to eat more of some of our foods today to gain the same amount of nutrient that was gained perhaps 50 years ago.  One USA think tank describes this additional bulk of food that we eat today as “empty calories” (3).

Croesus scientists contribute to the New Zealand Biofortification Initiative.  This is a joint project between Lincoln University and Massey University that seeks to understand trace element cycles in the soil.  Better understating of how trace elements move through the soil-plant-animal system may allow us to enhance the trace element nutrient content of food.  Technology that applies this understanding to improve animal and human health can be described as agronomic biofortification.


​(1)  Davis, D.R., Epp, M.D. and Riordan, H.D., 2004. Changes in USDA food composition data for 43 garden crops, 1950 to 1999.    

       Journal of the American College of Nutrition 23(6), 669-682.

​(2)  Pollan M., 2008.  In Defense of Food (Penguin, New York).

​(3)  Halweil, B., 2007.  Still No Free Lunch: Nutrient Levels in U.S. food supply eroded by pursuit of high yields.

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