Order given on petition cites environmental threats and radiation risk from naturally occurring radioactive minerals in beach sand
After banning mining of river sand and other minor minerals without the mandatory environment clearance , the National Green Tribunal (NGT) has now banned beach sand mining from the sea coasts of Tamil Nadu and Kerala. The ban was in response to a petition filed by the NGT Bar Association, which among other environmental risks enumerated risk of radiation from the mining of beach minerals, mostly consisting of rare earths—crucial for nuclear power. Studies show that separation of beach sand, which usually consists of rare earth ores like monazite, is a hazardous process in which workers and people living next to the mining sites are exposed to radiation.
A five-member bench headed by Justice Swatanter Kumar directed the chief secretaries of the two states, Kerala and Tamil Nadu, to file affidavits before August 29, as there have been many instances of illegal beach sand mining recorded in both the states. The affidavit filed by NGT Bar Association states that the Tirunelvelli, Tuticorin and Kanyakumari districts in Tamil Nadu are among areas worst affected by mining of beach minerals. It was pointed out to the tribunal that Viapar, a village on the Tamil Nadu coast in Tuticorin, witnessed illegal mining of 230,000 tonnes of beach sand minerals in the past one year.
Retired Tamil Nadu bureaucrat V Sundaram, who in 2012 had sought information under Right To Information Act, said that India is the third largest producer of monazite, an ore mostly found in the coastal parts of Tamil Nadu and Kerala. It is from monazite that thorium is extracted through a separation process. In view of the allegations levelled by Sundaram and many environmental activists from Tamil Nadu, the state government has appointed a three-member team to investigate illegal mining of monazite without environmental clearances from Kanyakumari, Tirunelvelli and Tuticorin. Sundaram estimates that Rs 96,000 crore worth of monazite may have been exported illegally to various countries by private beach sand manufacturers over the past decade. According to Atomic Minerals Directorate, monazite contains 0.2–0.4 per cent uranium in the form of uranium oxide and 4.5–9.5 per cent thorium as thorium oxide, depending on the region of origin or occurrence.
The presence of naturally occurring radioactive minerals (NORM) in rare earth elements (REE) raises environmental safety and security concerns, says P M B Pillai of the health physics unit of India Rare Earths Limited—the nation’s lone miner of rare earth, which has the licence to export the mineral. Even earlier when Department of Atomic Energy (DAE) faced allegations of allowing private companies to mine monazite deposits from the coastal areas, the department issued a notice in November 2012 stating no private firm is engaged in the production of rare earth ores such as monazite, while reaffirming that monazite is a prescribed element (an element approved by the Central government for production, export or use of atomic energy or research). DAE, since its inception, prohibits manufacture or extraction of NORM and its export by placing it under prescribed elements list. In a statement issued last year, DAE stated that it “has not issued any licence to any private entity either for production of monazite or for its downstream process for extraction of thorium or export of either monazite or thorium.”
DAE notification proves costly
In 2007, DAE issued a notification which delisted rare earth ores such as illimenite, rutile, leucoxene, garnet, sillimanite and zircon, making these minerals free to mine. Of these five minerals, illimenite, garnet and zircon are byproducts of separation of monazite ores from the raw sand found in coasts. Through this notification, DAE delisted these critical minerals from which REEs are derived, from the prescribed minerals list, making the Atomic Energy (Working of the Mines, Minerals and Handling of Prescribed Substance) Rules, 1984 redundant. It meant that private parties could mine the sands and export it to other countries without requiring clearances from Atomic Minerals Directorate. It has been alleged that the said notification led to an indiscriminate mining of sand by private parties in coasts around Tamil Nadu and Kerala. Sundaram says a total of over two million tonnes of monazite mined from the sand, equivalent to 195,300 tonnes of thorium at 9.3 per cent recovery, has vanished from the Tamil Nadu and Kerala coasts in the past 10 years.
Violators enjoy patronage
Complaints against illegal mining of beach sand minerals started as early as 2010 in Tamil Nadu. Following complaints from local environmental activists in Kanyakumari, the district administration closed down mining operations of private miner, V V Minerals. Although the company has denied owning any mineral separation facility to isolate monazite from raw sand, the company left large debris of unattended radioactive tailings, possibly consisting of thorium. In a report, the then district collector Rajendra Ratnoo stated that the V V Minerals was engaged in the process of mineral separation, which emits high radiation. Ratnoo’s report finds an echo with scientists tracking NORM. “The presence of NORM in the rare earth minerals in varying concentrations is quite often significant enough to result in occupational and environmental radiation exposures during their mining, milling and chemical processing for the extraction of the rare earth elements and compounds,” says Pillai.
The Kanyakumari district administration banned coastal mining in the district till V V Minerals approached Madras High Court. While the company claimed that it did not have any mineral separator, which was later verified by Atomic Energy Regulatory Board (AERB), experts such as Pillai have calculated the exact amount of radiation emitted from various sources of monazite found on the coasts of Tamil Nadu and Kerala (see ‘Environmental costs of monazite mining’).
On August 6, this year, V V Minerals was again raided in Tuticorin by the district collector Ashish Kumar. The raid report says the company had encroached upon 30 hectares of government land while it was allotted only 4 hectares by Tamil Nadu. On August 7, a day after the raid, the state government shunted out Kumar. While Tamil Nadu and Kerala government’s reply to NGT notice is awaited, V V Minerals insisted that it has not been running a separation facility for monazite.
|Environmental costs of monazite mining|
The term “rare earth” refers to group of seventeen elements, which are classified on the basis of the atomic weight. There are heavier rare earth elements as well as lighter rare earth elements, while yttrium, a lighter rare earth element has the characteristic of its heavier counterparts. An important disadvantage in mining of rare earths, which finds its applications in the nuclear and high-end electronics industries, is that it does not occur in concentrated form. This means most of the Rare Earth Elements occur in nature in combination with other elements. Rare earths in commercially exploitable quantities are found in minerals like monazite, bastnaesite, cerites, xenotime, gadolinite, fergusonite, allanite and samarskite.
According to P M B Pillai, a scientist with the health physics unit of Indian Rare Earths Limited (IREL), who has been studying the impact of rare earth mining from beach sands in Kerela and Tamil Nadu, most of the rare earth minerals contain some amount of thorium or uranium or both. “The presence of naturally occurring radioactive material (NORM) in the rare earths minerals in varying concentrations is quite often significant enough to result in occupational and environmental radiation exposures during their mining, milling and chemical processing for the extraction of the rare earth elements and compounds,” states Pillai, in his paper titled “Naturally Occurring Radioactive Materials” in the Extraction and Processing of Rare Earths published in 2010. According to IAEA, NORM comes from the materials which give rise to enhanced radiation exposure.
Pillai says that depending on the monazite concentration in the raw sand, radiation exposures of the order of 0.13-1.00 man-milli seivert (msv) per tonne are involved in the mining and separation of monazite. Monazite contains 0.2 -0.4 per cent of uranium and 4.5-9.5 per cent of thorium which occurs as oxides depending on the region of occurrence. Pillai says that hazards from the separation of monazite for extracting rare earths and radioactive elements, such as thorium could have internal and external sources. External hazards are due to high energy beta and gamma rays, while internal hazards are mainly due to alpha rays, emitting radionuclides characterised by decays. “The internal hazard is mainly by way of inhalation of thorium bearing dust and short-lived decay products of thoron gas. “Inhaled thorium bearing dust is deposited in the different regions of the respiratory tracts depending on the particle size,” he says.
Although, per capital average annual exposure of general public as determined by Pillai for monazite extraction plants have been estimated between the range of 1.00 and 9.00 mSv (AERB annual exposure limit is 30 mSv), he says that the wastes from the mining and milling from radioactive ores are potential sources of radiological impact.”Typically 600 to 700 kg of tailings containing radioactive elements generated per tonne of raw sand mined and used as back fill,” he says. Pillai, however, says even after a mineral extraction plant is closed down, the highly radioactive waste from mine and mill tailings will continue to pose a threat to the local public, while stressing the need to start better monazite processing facilities from raw sand.