By TZ Business News Staff.

Research has shown human exposure to uranium radiation causes cancer, genetic deformation, pulmonary fibrosis and leukaemia. The research findings raise a lot of  doubt on the prudence of Tanzania’s decision to start mining Uranium.

Uranium contaminates the air and water, which is how the radiation gets into the human body to cause cancer, genetic deformation and leukaemia.

Media reports say the Ministry of Energy and Minerals recently issued a special licence to Mantra Tanzania Limited, to start mining Uranium in Tanzania. This company is owned by Mantra Resources, an Australian subsidiary of AtomRedMetZoloto (ARMZ), a Russian mining firm. ARMZ will build and operate the Mkuju River uranium mine in southern Tanzania through Uranium One, its Canadian arm. Mantra Tanzania Limited has been operating in Tanzania since 2010.

The government granted Mantra a provisional licence in December, when construction on the underground mine started. Construction will take two years, and the site is said to contain at least 36,000 tonnes in known uranium deposits. Various reports suggest that the mine would extract 14,000 tonnes of the radioactive element annually. Such a rate of production would put Tanzania in a position to overtake Canada as the world’s second biggest uranium producer, according to Dalaly Peter Kafumu, the ministry’s former commissioner for minerals.

Currently, Kazakhstan is the number one uranium producer in the world, having produced 19,451 tonnes in 2011 and commanding 36% of the world’s total uranium production, according to the World Nuclear Association. Kazakhstan is followed by Canada, which produced 9,145 tonnes or 17% of the total production. “Tanzania is going to produce more than that,” Kafumu told the US Government-backed website, Sabahi.

Tanzania, nonetheless, would be limited to selling its uranium ore on the international market because it lacks the technology and funding to harness the element for domestic energy use, Kafumu told Sabahi.

But the deal already has caused controversy because of the mine’s location on a small patch of theSelous Game Reserve, which the United Nations Educational, Scientific and Cultural Organisation has designated for protection as a World Heritage Site. Activists have aired concerns about how mining for uranium in the area could threaten the environment and public health.

Uranium mining experts attending a six- day conference in Dar es Salaam recently warned the government against mining uranium, asking Tanzania to choose between expanding the country’s economy and waiting for horrendous health and environmental consequences. The warning came only three days after Acting Commissioner for Minerals Eng. Ally Samaje announced in Dar es Salaam that uranium reserves amounting to 178.8 million tons had been confirmed at Mkuju River in Ruvuma region.

The experts who sounded the warning belong to the International Physicians for the Prevention of Nuclear War (IPPNW), Speakers and Specialties on Uranium and its effects from Australia, the United States, Canada, Germany, Switzerland, the Rose Luxemburg Foundation of Germany (East Africa office), the Legal and Human Rights Centre (LHCR) of Dar es Salaam, and other African countries at a meeting where Tanzania played host.

The international conference that ended recently was deliberating on the impact of Uranium on health and environment.

The participants raised concern that Tanzania government came up with the decision to mine uranium without adequately assessing the potential effects to human health and the environment. They pointed out that uranium mining activities would cause adverse effects to safety and occupational health of mineworkers as well as environmental degradation and social disruption of local communities around mine sites.

They underscored that it would be “very hard” for the country to dramatically improve management systems for health, occupational safety and environmental performance in mining operations because it has failed to do so at other mining areas such as gold and diamond mines.

One of the experts, himself a Board Member from the International Physicians for the Prevention of Nuclear War (IPPNW), Prof Andreas Nidecker, stressed that the Tanzanian government should choose between money and human health as well as environmental consequences before it makes a final decision on uranium mining.

A research document from the Department of Medicine, University of New Mexico, Albuquerque identifies cancer as one of the diseases which can be acquired from uranium radiation. “ Excess lung cancer has been demonstrated in many groups of underground miners exposed to radon, including uranium miners and those mining other substances in radon-contaminated mines,” the reseach report reads in part.

“In the United States, most underground uranium mines had shut down by the late 1980s, but occupational exposure to radon progeny remains a concern for many other types of underground miners and other underground workers. Worldwide, uranium mining continues, with documented production in Canada, South Africa and other African countries, and Australia. Thus, radon in underground mines remains a significant occupational hazard….,” the paper reads.

Ruhuhu ProjectAnother study found a link between uranim and brain damange. The study found an association between cerebrovascular diseases mortality and cumulative radon exposure in French uranium mining group.

Cerebrovascular disease (CeVD) is a group of brain disfunctions related to disease of the blood vessels supplying the brain.


Another study was conducted at the Tselinniy mining complex in Northern Kazakhstan to investigate a link between uranium and genetic deformation. It was found that the frequency of chromosomal aberrations in uranium workers was significantly higher than in a matched control sample.

Scientists have a way of twisting words and that could get you confused. What they are saying is that uranium was found to damage chromosomes and therefore genes. (Source: The study report titled “Association of genetic polymorphism in GSTM1 and GSTT1 with the frequency of chromosomal aberrations in the uranium workers [in Russian], by Z. Zh. Vasileva. It was released in the year 2010).

In another study, a long-term persistence of chromosome aberrations was observed in Hungarian uranium miners. Results obtained from former Hungarian uranium underground miners suggest that chromosome aberrations caused during active mine work can persist for years after the occupational exposure ceased. (Source: Long-term persistence of chromosome aberrations in uranium miners, by G Mészáros, G Bognár, GJ Köteles, in: Journal of Occupational Health Vol. 46, No. 4 (July 2004), p. 310-315).


In Germany, another study found a link between Uranium and cancer. This study of German uranium miners’ study provides some evidence of increased risk of extrapulmonary cancers associated with uranim.

“Data from the German miners’ cohort study were analysed to investigate whether radon in ambient air causes cancers other than lung cancer. The cohort includes 58,987 men who were employed for at least 6 months from 1946 to 1989 at the former Wismut uranium mining company in Eastern Germany. A total of 20,684 deaths were observed in the follow-up period from 1960 to 2003. The death rates for 24 individual cancer sites were compared with the age and calendar year-specific national death rates. Internal Poisson regression was used to estimate the excess relative risk (ERR) per unit of cumulative exposure to radon in working level months (WLM).

The number of deaths observed (O) for extrapulmonary cancers combined was close to that expected (E) from national rates (n=3340, O/E=1.02; 95% confidence interval (CI): 0.98-1.05). Statistically significant increases in mortality were recorded for cancers of the stomach (O/E=1.15; 95% CI: 1.06-1.25) and liver (O/E=1.26; 95% CI: 1.07-1.48), whereas significant decreases were found for cancers of the tongue, mouth, salivary gland and pharynx combined (O/E=0.80; 95% CI: 0.65-0.97) and those of the bladder (O/E=0.82; 95% CI: 0.70-0.95).

A statistically significant relationship with cumulative radon exposure was observed for all extrapulmonary cancers (ERR/WLM=0.014%; 95% CI: 0.006-0.023%). Most sites showed positive exposure-response relationships, but these were insignificant or became insignificant after adjustment for potential confounders such as arsenic or dust exposure. The present data provide some evidence of increased risk of extrapulmonary cancers associated with radon, but chance and confounding cannot be ruled out.” (Source: Radon and risk of extrapulmonary cancers: results of the German uranium miners’ cohort study, 1960-2003, by M Kreuzer, L Walsh, M Schnelzer, A Tschense and B Grosche, Vol. 99 (2008), Published online 11 November 2008).

At New Mexico in the US, another study found people who were more at risk from getting uranium related health problems were those who worked in the underground uranium mines.

“A cohort mortality study of workers engaged in uranium milling and mining activities near Grants, New Mexico, during the period from 1955 to 1990 was conducted. Vital status was determined through 2005 and standardised mortality ratio (SMR) analyses were conducted for 2745 men and women alive after 1978 who were employed for at least six months. Overall, mortality from all causes (SMR 1.15; 95% CI 1.07-1.23; n = 818) and all cancers (SMR 1.22; 95% CI 1.07-1.38; n = 246) was greater than expected on the basis of US mortality rates.

Increased mortality, however, was seen only among the 1735 underground uranium miners and was due to malignant (SMR 2.17; 95% CI 1.75-2.65; n = 95) and non-malignant (SMR 1.64; 95% CI 1.23-2.13; n = 55) respiratory diseases, cirrhosis of the liver (SMR 1.79; n = 18) and external causes (SMR 1.65; n = 58). The lung cancer excess likely is attributable to the historically high levels of radon in uranium mines of the Colorado Plateau, combined with the heavy use of tobacco products. (Source: A cohort study of uranium millers and miners of Grants, New Mexico, 1979-2005, by Boice JD Jr, Cohen SS, Mumma MT, et al., in: Journal of Radiological Protection, Vol. 28 (2008), No. 3 (Sep), p. 303-325).

A study focusing on Lung cancer among Wismut uranium miners in Germany equally proved uranium causes cancer. A retrospective study among 59,001 former Wismut miners confirmed the excess relative risk estimate from radon progeny exposure known from previous studies among various other miner cohorts. However, the excess relative risk per WLM showed a maximum only 15-24 years after exposure and showed only a modest decline with time since exposure. “The results would indicate the need to re-estimate the effects of risk modifying factors in current risk models.” (Source: Lung cancer risk among German male uranium miners: a cohort study, 1946-1998, by B Grosche, M Kreuzer, M Kreisheimer, M Schnelzer and A Tschense, advance online publication 17 October 2006).


Another study in East Germany found uranium caused leukaemia. An individually matched case-control study of former uranium miners in East Germany was conducted with 377 cases and 980 controls. Using conditional logistic regression models, a dose-response relationship between leukemia risk and radon progeny could not be confirmed. Yet, a significantly elevated risk is seen in the category > or = 400 mSv when combining gamma-radiation and long-lived radionuclides.

CONCLUSIONS: The results suggest that an elevated risk for leukemia is restricted to employees with a very long occupational career in underground uranium mining or uranium processing. Moreover, the study does not support the hypothesis of an association between exposure to short-lived radon progeny and leukemia risk. (Source: Leukemia and exposure to ionizing radiation among German uranium miners, by M Möhner, M Lindtner, H Otten, HG Gille; in: American Journal of Industrial Medicine, Vol. 49, No. 4, April 2006, p. 238-248).

The Leukaemia problem was also discovered among Czech uranium miners. A study on Czech uranium miners shows that an increased risk of leukaemia is significantly associated with cumulated doses which mainly reflect exposures to long lived radionuclides in aerosol form and external gamma, whereas the contribution from radon to the dose is marginal. The increased mortality is mainly observed decades after exposure and is consistent with estimated internal dose to red bone marrow.

This study presents recent findings in an extended cohort of miners, now including nearly 10000 uranium and 2000 tin miners and followed up to 1999. A total of 30 cases of leukaemia were observed among Czech uranium miners, corresponding to standardized mortality ratio of 1.5, 90%CI: 1.0-2.1. The risk is analyzed in relation to cumulated dose from radon, external gamma radiation and alpha radiation from long lived radionuclides contained in mining aerosol.

Doses to red bone marrow were estimated using measurements of external gamma activities since the early 1960s and measurements of long lived radionuclides in the aerosol since the 1970s. The red bone marrow dose from inhaled long lived radionuclides is estimated by applying respiratory tract model and relevant biokinetic models. The substantial point is that the dose is cumulated even after the underground work has stopped. Another important point is the difference of the exposure by job category. By extrapolating available exposure data and applying models based on ICRP-66 and ICRP-68, individual doses were estimated using working histories, job matrix, and time since exposure.

The cumulated red bone marrow dose includes external gamma radiation, dose from radon and its progeny, and committed equivalent dose from long lived alpha-emitters in dependence on the individual length of follow-up. The mean cumulated dose is 158 mSv. Among uranium miners, about 52% of the total dose is due to inhalation of uranium and its decay products with aerosol in mines, about 33% is due to gamma radiation, and some 15% of the dose is from radon and its progeny. The risk coefficient (excess relative risk per sievert) corresponding to these estimates in the present study is 3.1 (90%CI: 1.3 – 5.4). The estimated risk is subject to a considerable uncertainty, due to small numbers and the uncertainty in the estimated dose. However, the magnitude of the risk is consistent with estimates from other studies. (Source: Leukaemia Among Czech Uranium Miners, by L. Tomášek, I. Malátová, in: Proceedings of the 9th International Conference on Health Effects of Incorporated Radionuclides Emphasis on Radium, Thorium, Uranium and their Daughter Products – HEIR 2004, GSF-National Research Center for Environment and Health, Neuherberg, Germany, Nov 29 – Dec 1, 2004, U. Oeh, P. Roth, H.G. Paretzke (Editors), Institut für Strahlenschutz, GSF-Bericht 06/05, p. 128-135).


Another research found uranium to cause Pulmonary fibrosis among uranium miners resulting from inhalation of radon progeny. The study found that many uranium miners have been disabled by and died of pulmonary fibrosis that was not recognized as an occupational disease.

A review of animal studies, complications from whole body irradiation, pulmonary function, and mortality studies of uranium miners led us to suspect radiation-induced chronic diffuse interstitial fibrosis in miners who had inhaled excessive radon progeny. A selected group of uranium miners (22) with severe respiratory disease (but no rounded nodules in chest films) were studied. Lung tissue from five disclosed severe diffuse interstitial fibrosis, with “honeycomb lung” in all. Some also had small anthrasilicotic nodules and birefringent crystals.

Although quartz crystals probably contributed, we concluded that the predominant injurious agent in these cases was alpha particles from radon progeny. This disease, after a long latent period, usually results in pulmonary hypertension, shortness of breath, and death by cardiopulmonary failure. (Source: Archer VE et al: Chronic diffuse interstitial fibrosis of the lung in uranium miners.

Journal of Occupational and Environmental Medicine, Vol. 40, No. 5, May 1998 May, p.460-474).

In the US, native American uranium miners were found to experience a higher risk of nonmalignant respiratory disease. The native American miners were found to have more nonmalignant respiratory disease from underground uranium mining, and less disease from smoking, than other miner groups, but are less likely to receive compensation for mining-related disease.

Uranium mining is more strongly associated with obstructive lung disease and radiographic pneumoconiosis in Native Americans than in Hispanics and non-Hispanic Whites. Obstructive lung disease in Hispanic and non-Hispanic White miners is mostly related to cigarette smoking. Current compensation criteria excluded 24% of Native Americans who, by ethnic-specific standards, had restrictive lung disease and 4.8% who had obstructive lung disease. Native Americans have the highest prevalence of radiographic pneumoconiosis, but are less likely to meet spirometry criteria for compensation. (Source: Mapel, DW; Coultas, DB; James, DS; et al.: Ethnic differences in the prevalence of nonmalignant respiratory disease among uranium miners, in: American Journal of Public Health, Vol. 87, 1997, No. 5 (May), p.833-838).

The Selous Game Reserve uranium mining project has met all legal requirements for being implemented, according to Tanzanian Vice President Mohamed Gharib Bilal, who recently visited the site of the Mkuju River project.

The project will bring in 728 billion shillings ($448 million) in foreign direct investments and create 1,600 jobs during the mine’s construction, he said, adding that the mine will eventually bring in 405 billion shillings ($249 million) in annual revenue.