Environmental Justice Case Study:

Thor Chemicals and Mercury Exposure in Cato-Ridge,     South Africa


Table of Contents


·       Problem

·       Background

·       Key Actors

·       Demographics

·       Strategies

·       Solutions/Outcomes

·       Recommendations

·       References

·       Back to Environmental Justice Case Studies


Recent investigation into the international shipping of hazardous wastes has focused attention on South Africa.  In the eastern province of Kwazulu-Natal, Thor Chemicals, Inc. of Great Britain has been accused of poisoning workers and putting surrounding communities at risk from mercury exposure.  Mercury-waste shipments from other countries have been received there at the plant in Cato-Ridge; these “exports and pollution around Thor were disclosed . . .as part of an investigation of toxic waste trafficking” (Lambrecht 17A)

Thor was receiving these shipments as part of their mercury recycling program; however, it was during the investigation by US journalists in 1989 that the breadth and severity of the resultant pollution came to light.  Water samples, taken from the Mngeweni River behind Thor and analyzed for mercury, were found to contain 1.5 million parts per billion (ppb) – 1500 times higher than the US limit for “sediment to be declared toxic” (Lambrecht 1A).  This river flows into the Umgeni River, which winds through heavily populated areas – all of which use the river for drinking water – and is the source of Durban’s drinking water.  Around the plant cattle graze and drink from the river; just down the stream, people “drink from the stream. . .play in the water, and people wash clothes in it.  Corn, sweet potatoes and other food grow on the rocky slopes leading to the stream”  (1A).  Mercury levels were found to be still 20 times the US limit as far as 40 miles downstream, near the coastal city of Durban.










·        World Health Organization

(Data compiled from Lambrecht 1A)

Soon after the initial studies were publicized, evidence of actual human casualties surfaced.  In 1992 three workers were found to be suffering from repeated, long-term mercury exposure; within months, one had died and another was in a coma.  The third could no longer talk or walk.  Another 27 workers were injured by mercury poisoning while working.  In response to rapidly-mounting public pressure, South African officials initially ordered Thor to clean up the pollution; soon after, they downplayed the potential threat, “saying that mercury has diminished or disappeared downstream” (1A).  One official of the Umgeni Water Board, Bill Richards, said “If the United States is worried about those poor black people at Cato Ridge, then your president should lift the sanctions and help improve their standard of living” (1A).











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Cato-Ridge is a small, industrial village in the self-governing province of Kwazulu-Natal (Kwazulu means land of the Zulu) in eastern South Africa.

Thor Chemicals, Inc., owned by Thor Holdings of Manchester, England, “runs one of the world’s largest mercury reclamation facilities” (Munnion 13) at Cato-Ridge.  Prior to Thor Chemicals’ move to South Africa in 1988, a mercury plant was operated, beginning in the mid 70s, at Margate, Kent, England.  During the 1980s, concerns were first raised by the Health and Safety Executive (HSE) “when allegations of excessive levels of mercury in the air and in workers’ urine were investigated” (Mills 10).  Threatened by prosecution by the HSE for over-exposure of workers to mercury, Thor closed its plant in 1987, relocating to South Africa, where untrained and unskilled Zulu-speaking labour was employed.  Within a year the “local water board there [in Natal] found high levels of mercury pollution in a nearby river” (Pallister 8).

While the Thor plant in England was a mercury-production facility, the relocated plant in Africa was a mercury-reclamation, or recycling, program.  As one of the only facilities in the world to form a large-scale mercury reclamation process, Thor quickly became target for many international companies facing the dilemma of what to do with waste mercury.  Incineration being the primary method for mercury disposal, it had largely been abandoned in most countries by the late 80s, due to the organic-generation (PCBs, dioxin) air releases and considerations of remaining ash disposal.  Thor Chemicals, Inc., operating in South Africa, was not faced with any regulations in this regard, as environmental codes were lax.


Mercury, an inorganic, is converted “by naturally occurring biological processes, into the highly toxic methylmercury” (EPA x).  Since mercury is a metal, it does not degrade to simpler compounds; as such, “it will always be present in the environment in one form or another” (x).  In addition to methylmercury being more toxic, it easily bioaccumulates in tissues.  Once in the tissues, it is a neurotoxin, affecting the central nervous system (CNS).  The symptoms of mercury poisoning vary, depending on the level of exposure, having “effects mainly on the motor and sensory systems, especially in the area of sensory-motor integration” (Mahaffey 397). Mercury poisoning causes symptoms “such as trembling, loss of muscle control, headaches, mental confusion, nausea and hair loss” (http://www.earthlife.org.za/campaigns/toxics/thor.htm).  As exposure levels increase, so does the likelihood of appearance of the following:  mental difficulties, impaired motor skills, tremors, coma and ultimately – death.

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Key Actors

·        Thor Chemicals, Inc.

Thor Chemicals, Inc., SA Ltd. is a British owned South African chemical company “engaged in the manufacture and marketing of. . .biocides, textile auxiliaries and metallic organic soaps” (Hoogervoorst 23).  When faced with initial findings of mercury-laden water leading from Thor, Steven Van Der Vyer, plant manager, dismissed them, saying they were “an isolated situation” (Lambrecht 1A); he blamed people from the area, “charging that they had stolen mercury-contaminated drums and then washed them out in the stream” (1A).  Indeed, people in rural communities consider the drums a commodity, each drum going for 70 rand (approximately $9) each; drums are used to store water and maize, and for cooking.

The mercury, itself, that Thor Chemicals in Cato-Ridge was receiving contained high levels of dangerous organic compounds:  “There are five mercury recycling plants in the USA but not one of them would touch waste with an organic content . . .higher than 3%” (Albertyn 215).  According to a company official, Thor “received $1,100 a ton” (Lambrecht 1A) to take these materials “from several countries” (1A).  The mercury waste that Cato-Ridge received contained organic contents “between 30 and 40% by volume” (215).  Working together, “the profit motive and poor state control [enabled] Thor to cut health and safety requirements to the extent that 28% of the workforce was diagnosed as having mercury poisoning” (215).


·        Thor Chemicals, Inc. Workers

The workers of Thor Chemicals, Inc., were the front-line of victimization.  Receiving R800 (approximately $110) a month, they were uninformed of the potential dangers of and precautions to take against mercury poisoning.  Instead, employees were either moved to another part of the factory or terminated:  “[w]hen workers recorded high mercury contamination levels they were advised to drink orange juice” (McGreal 14) in order to expedite the excretion of excess mercury.  One worker, Siphiwe Sibiya, ignored the incinerator clouds that spread around him:  “‘if you touched your lips with your tongue or washed your face there was a bitter taste.  My nails went black.  Sometimes I would take off my mask to find blood in it.  Then my nose was bleeding, my hands shaking’” (14).


·        American Companies

Two of the largest contributors to Thor Chemicals’ recycling program were American:  Borden Chemicals and Plastics and American Cyanamid Company.  These two companies combined to produce on average nearly 190 tons of mercury-related wastes annually (EPA 23); it was this waste that was shipped to Cato-Ridge.  The mercury-waste compound, containing mercuric chloride, is used as a catalyst in making plastics; when “about half the mercuric chloride in the catalyst is used up, [it is shipped] to Thor, which heats the material to release the mercury and uses it to manufacture more catalyst” (Schleifstein B3).



·        South African Government

Initially, the South African Government defended Thor Chemicals’ dealings, regarding the imported mercury waste as a raw material, since Thor “recycles mercury catalysts sold to overseas markets” (Cook 170).  Under increasing pressure, the Umgeni Water Board began routine water sampling, and ultimately “ordered Thor to exhume sediment and polluted water” (Lambrecht 1A).  Four months later, the Department of Water Affairs ordered Thor to close for four weeks, believing the source to be “from one of two plastic-lined, uncovered ponds behind the plant that hold mercury-contaminated water” (1A).  Shortly thereafter, “Thor was given a new license to continue its operations” (Chenje 241).  Despite continued investigation, in 1994, a secret memo from the Department of Environmental Affairs to the cabinet surfaced, in which it was declared that Thor Chemicals’ “sensible operations” in Natal demonstrated their “‘sound’ work” (Koch 9).


·        Earthlife Africa

Earthlife Africa, an environmental organization, campaigned to expose Thor Chemicals’ pollution.


·        Greenpeace International

Jim Vallette, a Greenpeace analyst, led the American charge against Thor Chemicals, raising American awareness.

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The overall ethnic makeup of South Africa consists of 75.2% black, 13.6% white, and 11.2% colored; in the Kwazulu-Natal province, the “Zulus people comprise about 300 tribes” (http://usaembassy.southafrica.net).  Durban, the closest city to Cato-Ridge, is a largely English-speaking area, with blacks living “in formal, low-income townships or informal, rapidly growing settlements” (http://usaembassy.southafrica.net).  Overall, the South African population is young:  50.3% are younger than 15 years, with the “largest numbers of young children found in Kwazulu-Natal” (http://www.gov.za/).

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The initial tactics employed in drawing attention to Thor Chemicals relied on publicity, on both national and international settings.  The first indication of injustice was uncovered by the St. Louis Post Dispatch, “investigating reports of pollution resulting from US waste shipments (Chenje 241).  From the first findings of water pollution, slowly, awareness began to grow.

Earthlife Africa, working in tandem with Greenpeace International, began compiling information on the activities and transgressions of Thor; beginning with reconnaissance photography, the two environmental organizations began building a case against Thor Chemicals and, later, the South African Government, itself.  By early 1992, following the poisoning and deaths of the first two workers at Thor, Earthlife accused the government of shielding Thor.  Thor documents, leaked to Earthlife Africa, workers were found to have mercury concentrations “in their urine as high as 600 to 1,000 parts per billion.  The international standard is 50 ppb” (Pallister 8) The South African government, however, pointed out that the imports did not fall “within the government’s definition of toxic waste” (Munnion 13).  Earthlife countered that the government “had allowed Thor to cloak its operations in secrecy, and said all attempts to obtain and publish details of alleged pollution and human contaminations had been obstructed” (13). 

Protests against Thor spread to the US, where its clients, American Cyanamid and Borden Chemicals were pressured by the public and investigated by the federal government. Back in Cato-Ridge, protestors held vigils and met a shipment at Durban, forcing it to turn away.


Following the deaths of the three workers in 1992 and months of investigation, Thor Chemicals was criminally charged by Great Britain for culpable homicide and violations of the Machinery and Occupational Safety Act.

In early 1994, a claim was filed against Thor Chemicals in the High Court in London on behalf of the first three victims, alleging Thor Chemicals was “negligent in allowing the transfer of a defective mercury production from England to South Africa” (Pallister 8) and “failed to protect the workers from the potentially deadly effects” (Mills 10) of mercury.

International Attention

In the months following the initial findings of the St. Louis Post-Dispatch study, worldwide attention focused on the international shipping of toxic wastes.  In 1990, Congress “argued . . .in a House Energy and Commerce subcommittee hearing” (Lambrecht 13A) whether or not a country is responsible for its wastes, once it leaves the country.  Additionally, the distinction between toxic waste and raw material was examined.

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Of all the strategies employed in focusing attention on Thor Chemicals’ conduct, publicity proved to be the most instrumental; litigation and international awareness both followed and resulted directly from the notoriety that publicity provided.


The increased international awareness that resulted from the pollution in Cato-Ridge had far-reaching effects on the international trade of hazardous wastes.  Three months after the initial revelations there, the “European Community formally agreed to ban hazardous waste exports to 68 former European colonies around the world” (Lambrecht 1A).  In addition, the Basel Convention, a waste export treaty drawn up by the United Nations, had been signed by all industrial nations except the US and New Zealand by 1994; while the treaty did not “kick in [until] the end of 1997. . .[c]ountries that continue[d] to export for recycling [were] subject to strict requirements; they must submit details on the composition of the wastes, the methods of recycling and the destination of residues or pollution from the recycling” (Lambrecht 1E).


The US Environmental Protection Agency (EPA) investigated both American Cyanamid Co., in Bound Brook, New Jersey, and Borden Chemicals and Plastics, in Geismar, Louisiana.  In the months immediately following disclosure of their role, American Cyanamid Co. filed to increase their mercury shipments to Thor, to 29,000 pounds “of mercury waste rather than 20,000 to 24,000 as originally planned” (Lambrecht 1A).  American Cyanamid finally stopped shipping mercury wastes to Thor “in 1991 upon learning of problems of the plant” (Zuckoff 11) – some two years later.  Borden Chemicals continued their mercury waste shipments until 1994, only ceasing under pressure by environmental groups and the EPA in response to a final shipment of 150 barrels to South Africa, which were ultimately recalled.  Following a five-year investigation, the Department of Justice (DOJ) decided not to file “criminal charges against Borden Chemicals and Plastics for shipping mercury-laden catalyst waste to South Africa” (Foster 9).  The decision was made when it was found that the “evidence [did] not show flagrant intent to violate the law” (9).  However, Borden Chemicals’ Geismar, Louisiana plant was fined $3.6 million and ordered to clean up a spill there, related to their overseas’ shipments.


After being criminally charged with culpable homicide and violations of the Machinery and Occupational Safety Act, Thor Chemicals pleaded guilty before an English court to lesser charges of negligence and were fined R14,500 (approximately $3900).  To date, this is the soul penalty imposed by a government (English or South African) on Thor Chemicals, Inc.


The civil claim filed against Thor Chemicals in 1994 on behalf of the first three victims underwent extensive legal contention; Thor Chemicals’ lawyers fought to have the suit heard in South Africa, for two reasons:  under “South African law [individuals] are prohibited from suing employers” (Mills 10); and South African “safety legislation is less advanced than in Britain” (www.mg.co.az).  Three years later, in 1997, Thor Chemicals settled out of court, paying R14.3 million ($2.1 million) in “claims by 20 South African workers for the effects of mercury poisoning suffered at is plant” (Schoonakker 13).  Less than a year later, in 1998, an additional claim – this time on behalf of 20 workers – was filed against Thor, for unspecified damages and in response to continued poor safety practices there.  Obtaining Thor medical records, Mark Colvin (Medical Research Council) said “‘the workers were frequently exposed to two to three times . . . with some workers exposed to above seven and even 12 times the WHO (World Health Organization) level’”  (Eveleth www.mg.co.az).  Soon after filing of the claim, Thor shifted its assets to a newly formed company called Tato Holdings.  This transfer reduced Thor’s net assets from about $28 million to $3.6 million and evoked charges of corrupt business charges.  In October of 2000, Thor Chemical Holdings agreed to pay the workers “about R2.7 million [about $353,000]” in an out-of-court settlement, “after they allegedly sustained mercury poisoning” (Bubesi 3) at the Cato-Ridge factory.  In both civil cases Thor Chemicals settled with no admission of liability.


Thor Chemicals, Inc. announced the closing of the plant in 1992.  The closing would be effective in 1996, after which no more mercury-waste would be accepted.  In 1994 the Department of Environmental Affairs toured the site, finding 10,000 drums of mercury-waste stored in a warehouse; these findings led to charges that the company never intended to recycle the waste and were, instead, merely stockpiling it.  The barrels were improperly stored and many were leaking.  In response, Parliament set up “an urgent investigation after ‘losing patience’ with Thor. . .for the long delay in resolving problems caused by leakage of mercury-containing waste from storage drums and resultant soil contamination” (Greybe www.mg.co.az).  In June of 2000, the USEPA was invited by South Africa’s Department of Environmental Affairs and Tourism to tour the Thor Chemicals processing plant, “to allow US pollution experts an opportunity to suggest methods for cleaning up mercury poisoning” (Arenstein www.africa.com).  What they found there shocked them.  One observer, environmentalist Thabo Madihlaba, said “[the] (fumes) inside the warehouses are deadly. . .storage drums are rotten and freely leak toxic waste, while the storage system is so bad that you cannot tell what is in the different drums” (Arenstein www.africa.com).  Environmental impact reports, conducted during the visit, found “lethal mercury waste was still leaching into the water table and a nearby spring used by surrounding villages” (Arenstein www.africa.com).

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As of December, 2000, the mercury wastes are still stockpiled at Thor Chemicals, Inc., in Cato-Ridge.  Going forward with the recycling is no longer financially feasible, and processing “‘will cause even more environmental hazards and public health problems than those that closed the plant’” (Arenstein www.africa.com).  The USEPA is working with South Africa’s Department of Environmental Affairs to “‘develop a coherent hazardous waste clean-up programme’” (Arenstein www.africa.com).  Meanwhile, the South African government grapples with the public relations dilemma of adopting a ‘return to sender’ policy, ordering the wastes back to their respective points of origin.


In talking with Mr. Orlando Carrazedo, via email, I found a source that had had experience within the South African Textile Chemical Industry, “of which Thor is one of many suppliers” (Carrazedo 11/19/00).  Mr. Carrazedo indicated that a pervading veil of ignorance, on the part of the employees and surrounding communities, coupled with mistakes made by Thor, resulted in “consequences which do not lend themselves to simplistic ‘blame apportioning’” (Carrazedo 11/28/00).  In particular, the workers, lacking knowledge of potential dangers, chose not to wear protective clothing.  In addition, the difficulties of security in protecting containers resulted in many barrel thefts and self-poisoning – this was due to the drums’ being a “valuable resource” in the “infrastructural context of minimal rural piped water facilities” (Carrazedo 11/28/00).  In summation, Mr. Carrazedo felt these circumstances, taking into account their occurrence in a Third World environment, “limitations of resources, expertise and regulatory uniformities, when impacted both by cultural and profit maximisation factors” (Carrazedo 11/28/00) result in issues that are not always readily explicit.

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Albertyn, Chris.  “The effluent of affluence:  How I came to see the dirt on Adam

Smith’s invisible hand.”   Hidden faces : environment, development, justice:

 South Africa and the global context.  Ed. David Hallowes.  Scottsville,

South Africa:  Russel Friedman Books, 1993.

“Borden Escapes Indictment; Enforcement.”  Chemical Week.  24 February 1999.

            29 November 2000. http://www.chemweek.com/

“British-owned firm in toxic waste row.”  The Daily Telegraph.  30 March 1992.

            21 November 2000. http://www.telegraph.co.uk/

“British waste firm blamed for Zulu mercury poisoning:  Chemical processors deny black

            workers are suffering bouts of madness.”  The Guardian.  12 April 1990.

            15 November 2000. http://www.guardiannewsltr.com/

Burch, Denise J.  “Re:  Thor Chemicals.”  E-mail to Corey M. Fondaw. 

30 November 2000.

“Business and Finance; South Africa:  Thor faces closure of Cato Ridge plant.”

            Business Day.  18 August 1998. 15 November 2000. http://www.bday.co.za/

Carrazedo, Orlando.  “Thor Chemicals.”  E-mail to Corey M. Fondaw.

19 November 2000.

Carrazedo, Orlando.  “Thor:  Orlando Carrazedo.”  E-mail to Corey M. Fondaw.

            28 November 2000.

“Chemical Plant Offers Workers About R2,7M.”   Business Day, South Africa.

13 October 2000.  15 November 2000.  http://www.bday.co.za/


Chenje, Munyaradzi and Johnson, Phyllis, Eds.  State of the Environment in

Southern Africa.  Johannesburg, South Africa:  The Penrose Press, 1994.

Cook, Jaclyn and Koch, Eddie, Eds.  Going Green:  People, Politics and the Environment

            In South Africa.  Cape Town, South Africa:  Oxford University Press, 1991.

Dixit, Ravi K.  “Re:  Case Study.”  E-mail to Corey M. Fondaw.  10 October 2000.

Durning, Alan B.  Apartheid’s Environmental Toll, Worldwatch Paper 95.  Johannesburg,

South Africa:  1990.

“Environment, Labor and anti-apartheid groups to protest American Cyanamid’s waste

            shipments to South Africa.”  Business Wire Inc.  9 April 1990.

            15 November 2000.  http://www.businesswire.com.

“Families sue over mercury poisoning.”  The Independent.  30 January 1994.

            8 November 2000. . http://www.independent.co.uk/

“Implications of employee injury cases.”  Environmental Liability Report.  1 July 1995.

            8 November 2000. http://www.environcorp.com/

“Inquiry targets Natal poisoning outbreak.”  The Independent.  29 March 1992.

            8 November 2000. http://www.independent.co.uk/

“Justice Department won’t indict Borden Chemicals on waste shipments.”

            AP Online.  12 February 1999.  15 November 2000. http://www.ap.org/

Lambrecht, Bill.  “Waste Pollutes Drinking Water in S. Africa.”  St. Louis Post-Dispatch.

            26 November 1989.

Lambrecht, Bill.  “Mercury Waste Exports Bring Rebukes in Congress.” 

St. Louis Post-Dispatch.  3 December 1989.


Lambrecht, Bill.  “Panel Weighs Policing of Dumps Outside US.” 

St. Louis Post-Dispatch.  25 January 1990.

Lambrecht, Bill.  “S. Africa Padlocks Polluters – Mercury from U.S. Poisoning Zulus.”

            St. Louis Post-Dispatch.  13 April 1990.

Lambrecht, Bill.  “Protests Get Company to Review Policy on Wastes.”

            St. Louis Post-Dispatch.  18 April 1990.

Lambrecht, Bill.  “S. Africa Bars Wastes Exported by U.S. Firms.” 

St. Louis Post-Dispatch.  29 September 1990.

Lambrecht, Bill.  “Mercury Plant is Closing – Thor Plant in S. Africa Poisoned Stream,

Land.”  St. Louis Post-Dispatch.  10 May 1992.

Lambrecht, Bill.  “Ban on Exporting Waste Proposed.” St. Louis Post-Dispatch.

            1 March 1994.

Lambrecht, Bill.  “Waste Tightening - Third World Acts Against Toxic Garbage.”

            St. Louis Post-Dispatch.  3 April 1994.

Lambrecht, Bill.  “Thor Chemicals.”  E-mail to Corey M. Fondaw.  15 November 2000,

            18 November 2000, 30 November 2000, 1 December 2000

Mahaffey, Kathryn R.,PhD.  “Methylmercury: A NEW LOOK AT THE RISKS.”

U.S. Department of Health and Human Services.  Public Health Rep; 114

(1999):  396-413.

“Mercury poisoning victims win pounds 1.3m in landmark case.”  The Independent.

            12 April 1997.  8 November 2000. http://www.independent.co.uk/

“Mercury staff ‘were poisoned.’”  The Independent.  1 April 1997.  8 November 2000.


Prince, George R.  “Re:  Thor Chemicals.”  E-mail to Corey M. Fondaw.

            10 October 2000.


“Protest Awaits Shipment of Deadly US Toxic Waste.”  Africa News.  15 March 1994.

            6 November 2000. http://www.africanews.org/

“Protest to Meet LA Chemicals in South Africa; Shipments Will Go On, Firm Says.”

            The Times-Picayune.  17 February 1994.  15 November 2000.


“SA Employees of UK-Based Firms Face New Threat.”  Business Times. 

22 November 1998.  15 November 2000. http://www.btimes.co.za/

Science Applications International Corporation, submitted to United States EPA.

Analysis of Current Mercury Waste Generation and Treatment.  Chantilly, VA:

TechLaw, Inc.  1998.

“S. African Workers Sue British Firm Over Poisoning.”  The Guardian.

29 September 1994.  15 November 2000. http://www.guardiannewsltr.com/

South African Embassy.  2000.  29 November 2000.  http://usaembassy.southafrica.net/

“South African factory staff sue British firms; Black workers are claiming damages for

            death and injury from industrial poisoning.”  The Independent.  1 April 1997.

            8 November 2000. http://www.independent.co.uk/

South Africa Government Online. 6 December 2000.

Government Communications (GCIS).   6 December 2000.  http://www.gov.za/

“South African Lawyer Here to Prepare Case Against Chemical Firm.”  Africa News. 

            1 March 1996.  8 November 2000.  http://www.mg.co.az/

“South Africa; Lethal Toxic Waste Still Leaking Into KZN Water Table – ENJF.”

            Africa News.  21 June 2000.  1 December 2000. http://www.africanews.org/


“South Africa; New Claim against chemical giant Thor.”  Africa News. 

20 February 1998.  21 November 2000. http://www.mg.co.az/

“Thor Pays Workers for Mercury Poisoning Claims.”  Chemical Week.  23 April 1997.

            29 November 2000. http://www.chemweek.com/

Uku, Richard.  “Re:  Thor Chemicals.”  E-mail to Corey M. Fondaw. 

30 November 2000.

United State EPA.  Mercury Research Strategy.  Washington, DC:  1999.

“US firms ship mercury, and South Africans suffer; Foul Trade.”  The Boston Globe.

            12 July 1994.  15 November 2000. http://www.boston.com/globe/

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