|SCIENCE & TECHNOLOGY|
in groundwater: FAQs Prof Yash
Pal This Universe Trends
Prof Yash Pal
in groundwater: FAQs
We have all ready various news items about high concentration of uranium in groundwater in certain areas of Punjab. Here are answers to frequently asked questions (FAQs) about this phenomenon:
What is uranium?
It is naturally occurring heavy metal and is disbursed at low abundance in normal rock forming minerals making it a trace element. It is essential constituent of about 100 minerals. Of these, most important mineral is uraninite (UO2).
What is the concentration of uranium in various rocks?
It is found in small quantities in soil and rocks and the amount varies from place to place. The average concentration of uranium in earth’s crust is about 2.7 ppm (parts per million). Among igneous rocks, granites are known to contain maximum concentration of about 4.8 ppm. In sedimentary rocks, maximum concentration of about 4 ppm is found in shales. In Lignite, it ranges between 10 and 2500 ppm. Soil is found to contain about 1 ppm though it ranges between 1 to 5 ppm.
What is radon?
Radioactive decay of uranium produces radium which further decays to form radon gas. Therefore, measurements of radon gas in groundwater and soils etc. are useful in finding out radioactive hazards and such data has been extensively used in the US to find out radioactive hazardous areas.
High radon emissions are associated with some rocks like granites, phosphatic rocks and shales rich in organic materials. The level of radioactivity in air due to radon is measured in Becquerel per cubic meter (Bq/m3). One Becquerel represents one atomic disintegration per second. In water, Bq/L is also used to measure radon/radioactivity.
What is the average concentration of uranium in groundwater drawn from different rock terrains?
The average uranium content in groundwater in igneous terrains is 4.5 ppb (parts per billion); in sedimentary terrains about 2.62 ppb; in metamorphics 4.4. ppb and in ground water from sand and gravels about 2.5 ppb though it can range from 0 to 74 ppb.
What is the permissible concentration of uranium in drinking water?
United States Environmental Protection Agency (USEPA) has set 30 `B5g/l (micrograms/ltr); the Atomic Energy Regulatory Board (AERB), India has set a limit for uranium in drinking water at 60 `B5g/l. The World Health Organization (WHO) set a provisional guideline of 15 `B5g/l. These limits are often exceeded in the drinking water for many communities worldwide.
Which countries have uranium hazard in ground water?
The results of uranium concentration in drinking water of different countries. Indicate that most of the countries do not have uranium hazard in drinking water except Finland (0.5 – 6000 ug/l); China (0.1 -28 ug/l); Jordan (0.04 – 1400 ug/l) and Switzerland (0.1 – 40 ug/l).
What is the average concentration of uranium in ground water in India?
Sahoo et al. 2009 reported uranium concentration ranging from 0.1 `B1 0.01 to 19.6 `B1 1.8 ug/l in drinking water of India. According to the study, all the values fall within permissible limit of 30 ug/l of USEPA. The authors also reported that annual dose due to uranium in drinking water ranges from 0.14 to 48 uSv/year for various age groups. However, values as high as 471 ug/l have also been reported.
Does high concentration of uranium in ground water occur around uranium mines in India?
The study conducted by scientists of Atomic Mineral Division (Saxena and Verma, 2001) indicate uranium concentration is well within the limits in groundwater round uranium exploratory mines.
Do we have high concentration of uranium in ground water in Punjab?
From the data reported by various workers, it has been found that in south western parts of Punjab covering Bathinda, Mansa, Faridkot and Ferozepur districts, hot spots having concentration more than 60 ug/l (AERB limit) in the upper aquifers up to about 60m depth occur at scattered places. Within a single village, there is lot of variation in concentration of uranium in groundwater.
What is the concentration of radon in ground water of Punjab?
Bajwa et al. 2005 studied radon concentration of groundwater from Punjab and reported radon concentration ranging from 1.0 to 48 Bq/l from groundwater of hand pumps and tube wells. The values fall within the permissible limit of 400 Bq/l.
Are soils in Punjab safe from the radioactive hazard?
In soils of Punjab, uranium concentration is not posing any hazards as revealed by data reported by Mehra et. al. 2007 from 30 locations in Malwa belt. Further, the radioactivity levels in soil samples were found to be comparable to the national global average levels by BARC (2009).
What are the possible causes of high concentration of uranium in ground water?
The causes of high concentration of uranium in ground water can be Geogenic (natural) i.e. from the rocks and mobilization of uranium from within the sediments or Anthropogenic (man’s activities) such as, thermal burning of coal, use of phosphatic fertilizers and Air blown from Afghanistan. However, detailed studies are required to find out the cause of high concentration of uranium.
What are the remedial measures?
The best remedial method recommended by USEPA is the use of Anion Exchange and Reverse Osmosis for uranium separation in water and is also being successfully followed in U.S.A. The major precaution one has to take is regarding the safe disposal of effluents/reject which may be become rich in radionuclide.
What can people do to avoid the effects of uranium toxicity?
Avoid use of hand pump water which also contains excess fluoride more than permissible limit and responsible for bone and joint problems (Singh and Kishore, 2009) and use filtered canal water. In addition, they should increase the use of lemon, citrus fruits and garlic in their diet.
What is the need of hour?
A detailed interdisciplinary project needs to be taken up collectively by the experts from the medical sciences, soil sciences, geosciences, physical and chemical sciences and veterinary and agricultural sciences.
The writer is Professor at the Centre of Advanced Study in Geology, Panjab University, Chandigarh.
I have seen some insects decomposing a dead body. Why don’t these organisms attack our body when we are alive?
This proves that when we are alive we also have a defence mechanism working. Our guts and other parts of body are full of a variety of bacteria that help in the life processes. Our immune cells produce soldiers that fight invaders that might want to use our bodies as tasty food or create programmes that might interfere with our living functions. When we die we are just so much organic matter, like fallen leaves or dead ants. Life matters!
Is there any relation between mass and time? I have heard that time is inversely proportional to mass.
I think you are a little confused. There is no direct relation. Perhaps one could relate the mass of living things and their living period. Ordinarily flies and small insects do not live long. Dogs and cats live much longer. Elephants have a longer life, so do human beings.
But going into another dimension, very heavy stars do not live very long, because the internal nuclear reactions work at higher temperature and consumption of light elements proceeds fast. This is as against smaller stars whose interiors nuclear furnaces are cooler resulting in a slower consumption of material that can fuse to produce energy, thereby giving them a longer life. Because of such special reasons you could find a relation between the life of stars and their mass.I suspect I have moved much further than you might have expected, but I did not understand your question in any other sense.
Why do we feel hard on touching our nose even though the bone is not present?
I do not quite understand your question. It possible, however that you refer to the absence of a thick bone in the upper part of the nose. I might be saying some thing stupid but I suspect that some of the felt hardness might be similar to the one we get to feel at the edge of the sole of a shoe, where two or more layers of leather are tightly sewn together! There are many experts who would like to shoot me down. Please go ahead, but let me know.
launched a $600 million global initiative on Wednesday to raise rice
yields and reduce the impact of rice production on the environment,
which they said could also help 150 million people escape poverty by
2035. The Global Rice Science Partnership will oversee research over
the next five years to boost yields and breed stronger strains that
can resist flooding and threats from climate change.
Stem cells turned injured rodents into mighty mice
CHICAGO: Injecting stem cells into injured mice made their muscles grow back twice as big in a matter of days, creating mighty mice with bulky muscles that stayed big and strong for the rest of their lives, US researchers said on Wednesday. If the same applies to humans, the findings could lead to new treatments for diseases that cause muscles to deteriorate, such as muscular dystrophy.
Tarantulas help scientists break down human fear
using tarantulas to unpick human fear have found that the brain
responds differently to threats based on proximity, direction and how
scary people expect something to be. Researchers from the Cognition
and Brain Sciences Unit in Cambridge, England used functional magnetic
resonance imaging, or fMRI, to track brain activity in 20 volunteers
as they watched a tarantula placed near their feet, and then moved
closer. — Reuters