Dr. Wahied Khawar Balwan
According to many researchers working on ‘Climate Change’, climate change’s impact on public health will be extensive, ruthless and affect all sectors of the public health system. A new affliction that will result from climate change has surfaced: kidney stones. Rising temperatures and increased dehydration linked to global warming will boost kidney stone rates around the world. The objective of this article is to highlight the link between climate change and the rise in incidence of kidney stones around the world, the causative factors for occurrence of kidney stones, the socioeconomic impacts, research issues and methodology to combat the disease.
Global warming will stir up the plagues of Malaria, Dengue fever, Hantavirus and Kidney stones. It seems an odd melancholy to include kidney stones on the list of climate changerelated health problems which usually run to infectious diseases and shortages of food and water. But researchers predict that rising temperatures will make kidney stones more common. The real issue is that climate change cuts across so many different pathways, and kidney stone is one interesting example. Kidney stones can be extremely painful. They are often caused by dehydration as the body is unable to flush minerals out of the system. Rising temperatures and increased dehydration linked to global warming will boost kidney stone rates around the world. There is an urgent need to gauge the potential impact of global warming on kidney stone risk. For this, the researchers must analyze and plot prior disease incidence in world geographic regions, along with valid reports assessing global warming patterns. This would help in developing mathematical models to compute all relevant information applicable to the region under consideration.
WHAT ARE KIDNEY STONES?
The kidneys are two bean-shaped organs that are roughly four inches in length and located towards the back of the abdomen, on either side of the spine. Kidneys work by removing waste products from the blood. The waste products are transferred into the ureter (the tube that attaches each kidney to the bladder) along with excess fluids, and from there they are disposed of as urine. The sterile blood is then transferred back into the body. There are different main types of kidney stones namely Calcium stones are made from calcium and phosphate, or calcium and oxalate; Struvite stones contain magnesium and ammonia, and are often horn-shaped and quite large; Uric acid stones are usually smooth, brown and softer than other forms of kidney stones; Cystine stones are often yellow and look like crystals rather than stones.
Kidney stones come in a variety of shapes, sizes and colours. Some look like grains of sand while, in rare cases, others can grow to the size of a golf ball. The waste products are usually dissolved in the fluids that form urine but, occasionally, they can form crystals that collect around the inside of the kidney. The crystals may gather over time to form a hard stone-like lump. This is a kidney stone. After a kidney stone has formed, it will often pass through the urinary system as it tries to be passed in urine. However, it is fairly regular for a stone to block part of the urinary system, such as the ureter or the urethra (the tube that carries urine from the bladder to the outside of the body). If this happens, you may feel acute pain in your abdomen or groin. An obstruction in the urinary system can also lead of infection, kidney injury or, sometimes, kidney collapse.
Common symptoms of kidney stones include intense pain in the back or side of abdomen, or occasionally in groin, nausea, blood in urine, which is often caused by the stone scratching the ureter, cloudy or smelly urine, a burning sensation during urination and fever (a temperature of 38° C or 100.4° F, or higher). If one had kidney stones, he/she may also feel like he/she needs to urinate more often even if he/ she does not need to. The exact cause of kidney stones is unknown. They are usually formed following a build-up of a substance in the body, such a calcium, ammonia, uric acid or cysteine. Certain medical conditions, such as cancer or kidney disease, can also increase the risk of developing kidney stones. This is usually due to the treatment for these conditions. One is at a greater risk of developing kidney stones if one is dehydrated or do not drink enough fluids; one eats a high-protein, low-fibre diet; one is inactive or bed-bound; kidney stones run in one’s family; one has had several kidney or urinary infections; one has had a kidney stone previously; only one kidney works, and; if one has had an intestinal bypass or a disease of the small intestine, such as Crohn’s disease (inflammation of the gut). There is also evidence that certain medication, such as aspirin, antacids, calcium and vitamin D supplements, may increase risk of developing a kidney stone.
GLOBAL WARMING AND KIDNEY STONE DISEASE
According to researchers in UT South-western Medical centre and UT Dallas, global warming is likely to raise the proportion of the population affected by kidney stones by expanding the higherrisk region known as the “kidney-stone belt” into neighbouring states in United States of America. Kidney-stones are more common in the warmer parts of the U.S. The Southeast is known as the “Kidney-stone belt” because of the high incidence of kidney stones in the population living in Alabama, Arkansas, Florida, Georgia, Louisiana, Mississippi, North Carolina, South Carolina and Tennessee. About 13% of men and 7% of women experience kidney stones during their lives, yet those rates can double in the “kidney stone belt”. According to the U.S. National Kidney and Urologic Diseases Information Clearinghouse, about 5 percent of Americans develop kidney stones at some point, with the risk rising as men and women enter their 40s and 50s, respectively.
Dehydration (lack of fluids) in one of the risk factors linked to kidney-stone disease and global warming will aggravate this effect. It is predicted that by 2050, higher temperatures will cause an additional 1.6 million to 2.2 million kidney-stone cases representing upto a 30 percent growth in some areas of United States of America. The study shows that global warming causes a direct medical consequence on human beings. It is certain that climate change will continue and increase, and it is equally certain that increased temperatures will lead to increased kidney stone formation.
Kidney-stone disease can be caused by both environmental and metabolic problems. Little volume of urine directly enhances stone risk by increasing the concentration of stone-forming salts. They can occur from either taking in too little fluid or losing too much through dehydration. The climate change was forecast in the study using models of global warming obtained from the Inter-governmental Panel on Climate Change’s 2007 Fourth Assessment Report, in which predicted temperature increases are based on expectations of future greenhouse gases. The potential impact of global warming on kidney stone risk was gauged using two studies that reported kidney-stone rates in various geographic regions and associating regional kidneystone rates with local mean annual temperatures, the investigators were able to derive two mathematical models relating temperature to kidney-stone risk. Both models of kidney-stone risk predicted that the current kidney-stone belt prevailing in United States of America will expand with global warming, although the exact extent and location of the change was different. One model predicted that the increase will be concentrated in the southern half of the country, while the other model pointed to an increase in the upper Midwest. Taking into account the estimated future populations in those areas, increased temperatures were predicted to cause 1 million to 2 million more cases of kidney-stone disease. According to Kristina Penniston, a registered dietician and associate scientist in the department of urology at the University of Wisconsin School of Medicine the Public Health in Madison, it seems entirely likely that incidence of kidney stones will increase with global warming, primarily because one of the driving forces of incidence is hydration, and with global warming people will tend to be less well hydrated.
The study concluded that the increase in kidney stone cases could increase health-care costs by as much as $1 billion. This problem is not only confined to the U.S. This will also affect southern Europe, south-eastern Europe, and Southeast Asia. As the treatment options in Southeast are more limited, countries in that region will certainly experience a much more severe impact on health. When people relocate from area of moderate temperature to areas with warmer climates, a rapid increase in stone risk has been observed. This has been shown in military deployments to the Middle East for instance.
PREVENTING KIDNEY STONES
Drinking Plenty of Water
Kidney stones can be avoided by drinking plenty of water each day and avoiding getting dehydrated. It is very important to keep the urine diluted to avoid waste products forming into kidney stones. The degree of dilution of urine can be ascertained by looking at the colour of it. The darker it is, the more concentrated it is. Urine is usually a dark yellow colour in the morning because it contains a build-up of waste products that the body has produced overnight. Normally, one should drink at least six to eight glasses (about 1.2 litres) of water each day. However, people who have had a kidney stone before are encouraged to increase their fluid intake to two to three litres each day in order to ‘flush out’ waste products that can cause stones to develop. Drinks such as tea, coffee and fruit juice can count towards your fluid intake, but water is the healthiest option and is best for preventing kidney stones. One should also make sure that he/she drinks more than the recommended daily amount when it is hot, or when exercising, in order to replenish fluids that are lost through sweating.
Changing one’s diet
If kidney stone is caused by an excess of calcium, it is advisable to reduce the foods containing oxalates in diet. Oxalates prevent calcium from being absorbed by the body, so it can accumulate in kidney and form a stone. The amount of calcium in diet should not be reduced unless recommended by the medical practitioner. To prevent developing an uric acid stone, the amount of meat, poultry and fish in diet must be reduced. Medication may also be prescribed to change the levels of acid, or alkaline, in urine.
The study conducted by the researchers in UT South-western Medical Centre and UT Dallas, in fact, is an eye-opener in establishing the exact link between kidney stones and global warming. Such researches have to be carried out extensively in all parts of the world. Many of the states in our country, particularly the states in northern part of our country are subject to climate extremes with cold conditions prevailing in the period November to February and hot conditions prevailing in the period March to June. Because of global warming, the maximum air temperatures at some places may reach extreme values during the hot summers and the risk of kidney-stone disease may increase further and further. In this situation, it becomes imperative to carry out a detailed investigation and derive mathematical models to forecast the risk of kidneystone occurrence in future. It will be quite interesting to know how global warming will impact the diet of people, because there are also many nutritional factors related to kidney stones and climate change affects the nutrient composition of the plants that we grow and the animals that we eat. For example, fruits and vegetables are inhibitors of stones. So the question then is, will people be eating less of that as temperatures rise because these things don’t grow as abundantly? And will that then alter people’s risk for stones? These are some of the important issues to be investigated.
Considering these aspects/issues, the need of the hour is to carry out interdisciplinary research involving researchers in the fields of medicine, climatology, water supply and sanitation, sociology and economics. This research must be carried out simultaneously (during the same period of time) by different groups involving different regions of the country. The findings of the studies must be debated on a common platform for exchange of views and concluding recommendations. The recommendations must be put-forth before the Ministry of Environment and Forests (MoEF) at the national level for enabling the government to take policy decisions and device strategies to combat the risk of escalation in kidney stone disease due to global warming.
‘Any Error in this manuscript is silent testimony of the fact that it was a Human effort’
Dr. Wahied Khawar Balwan,
Assistant Professor Zoology
Govt. Degree College Kilhotran, Doda.
E-mail: [email protected]