Fish is the first choice of every Bangladeshi; by tradition and nature rice and fish is our stable food and source of protein; accordingly the myth “Mas-A- Bata-A-Bangali” (Bangali are being with Fish and Rice). Fish also is our one of the resource; our sea Bay of Balgle have a wide verity of fish species. But now this fish are threatened by exposed or contaminated by toxic chemical. The chemicals are reproductive or developmental toxins, and are carcinogenic in nature. It has found that mercury exposed in the sea fish and other persistent chemical contaminants are in all food groups; and the exposure to persistent organic pollutants (POPs) has been linked to serious diseases and developmental disorders, including Breast and other types of cancer, Immune system suppression, Nervous system disorders, Reproductive damage, Disruption of hormonal systems, Neurological disorders, Insomnia, Hearing loss, Vision disruption.
Natural Toxins
Toxic chemicals can produce naturally by living organisms. These toxins are not harmful to the organisms themselves but they may be toxic to other creatures, including humans, when eaten. Some plants have the capacity to naturally produce compounds that are toxic to humans when consumed. For example, under certain conditions, microscopic algae (tiny plants) in the ocean can produce compounds that are toxic to humans but not to shellfish that eat this algae. When people eat shellfish that contain these toxins, illness can quickly follow.
Mycotoxins are another group of natural toxins. The word mycotoxin is derived from the Greek word for fungus 'mykes' and the Latin word 'toxicum' meaning poison. Mycotoxins are toxic chemical products formed by fungi that can grow on crops in the field or after harvesting. The foods that can be affected include cereals, nuts, fruit and dried fruit, coffee, cocoa, spices, oilseeds and milk. There are now more than 300 known mycotoxins of widely different chemical structures and differing modes of action - some target the kidney, liver, or immune system and some are carcinogenic. Common mycotoxins include aflatoxins, ochratoxin A, ergot alkaloids, fumonisins, patulin, trichothecenes (such as deoxynivalenol which is also known as vomitoxin) and zearalenone.
Man-Made Toxins
The use of agrochemicals, including pesticides, remains a common practice especially in tropical regions like Bangladesh and other South Asian countries. Cheap compounds such as DDT, HCH (Lindane), that are environmentally persistent are today banned from agricultural use in developed countries, however they remain popular in developing countries including Bangladesh. As a consequence, persistent residues of these chemicals contaminate food and are dispersed within the environment. In addition, indiscriminate use of pesticides also results in poisonous vegetables and contaminated food and drinking water. Toxic chemicals leach pathogens through the food chain, and food poisoning outbreaks from agro land spread to homes and restaurants, and contaminate drinking water reserves and supplies.
Expose of POPs
A report released by the Pesticide Action Network that, through their daily diets, global consumers are exposed to 70 persistent organic pollutants (POPs) - residues of a class of toxic chemicals including DDT, dioxin, mercury and lead, PCB, HCB, b-HCH, a -endosulfan and dieldrin.
The report analyzes chemical residue data collected by the US Food and Drug Administration (FDA) and finds persistent chemical contaminants in ALL food groups.
Exposure to POPs has been linked to serious diseases and developmental disorders, including:
Breast and other types of cancer
Immune system suppression
Nervous system disorders
Reproductive damage
Disruption of hormonal systems
Neurological disorders
Insomnia
Hearing loss
Vision disruption
Tuna and other sea fish contained mercury!
Canned tuna is a healthy source of vitamins and protein, but it also contains some levels of mercury. Which is packed with lean protein and omega-3 fatty acids which studies show benefit the heart, brain, and eyes.
But the mercury poisoning experts acknowledge that tuna and many other sea fish does contained mercury, even the American and European fish industries are acknowledged it. It's a chemical that could be toxic at certain levels and erase those benefits as well as cause problems in an unborn baby. The methyl mercury is a potent neurotoxin that can harm the unborn baby and caused children to be born with cerebral palsy, with small brains, and undersize brains.
According to the US TV CBS 5 reporting, it has proofed by a lab testing tuna and most of other sea fish exposed with mercury. Sue Kwon a CBS5’s reporter has conducted her own unscientific experiment tracking consumption of canned tuna and measuring levels of mercury. The experiment involved eating 20 five-ounce cans of albacore tuna over 20 days and not eating seafood that could contain mercury and impact the experiment. After eating 20 cans, a phone call comes from the doctor. Dr. Jane Hightower said, "I want you to stop your experiment. It's not worth the risk."
The experiment illustrates that even at levels below the WHO limit, mercury accumulates in the body reaching what Dr. Hightower and an independent lab flagged as "high" levels in a short period.
At the start of the experiment, Sue Kwon's blood mercury level was low at 4 micrograms per liter. In 10 days, it went to 8.9 micrograms per liter. Then in 10 more days, it climbed to 17.2 micrograms per liter. By day 20, it had quadrupled. "Anytime in a woman's body she reaches a 14 or 15 she stands a chance of knocking IQ points off her child's brain," Hightower said.
If the experiment continued, Dr. Hightower said the mercury would accumulate mercury faster and the level would spike. Hightower said, "You probably would've doubled again in another 10 days and then probably leveled out at in a steady state somewhere in the 50 range."
Hightower's patients with blood mercury levels that high have experienced these symptoms. "They get body aches, joint pain, muscle aches, head ache, trouble sleeping, troubles with thinking and memory, stomach upset," she said.
In Los Angeles recently, tests were conducted on seafood products sold in grocery stores and restaurants with some alarming results. In one case, the swordfish from a local grocery store contained 4.027 parts per million (ppm) of mercury, more than four times the limit suggested by the U.S. Food and Drug Administration. Despite the banning of chemicals in food production in the US, traces of these toxins continue to be found in seafood. There is speculation that naturally occurring mercury in the marine ecosystem is intensifying due to climate change – a clear indication that we can never be completely safe from eating seafood - in Bangladesh as well.
What is Mercury?
Mercury is a naturally-occurring element which is found in soil and rocks and also exists in lakes, streams and oceans. In addition to natural sources, mercury is released into the environment by human activities such as pulp and paper processing, mining operations, and burning garbage and fossil fuels. We absorb small amounts of mercury from a number of sources, both natural and artificial, in our immediate environment. These include amalgam dental fillings, air and water pollution, and trace amounts in food. Of the different kinds of food we eat, fish contains the largest source of mercury.
It is well known that high amounts of mercury can damage the nervous system of people and animals. In trace amounts, however, the effects are not clearly known. Long-term studies are being conducted to determine the effects of low levels of mercury, especially on young children.
Mercury in fish
Mercury exists in two different forms, the organic and the inorganic. In the aquatic environment, the most prevalent form of mercury is methyl mercury, the organic form, which binds tightly to the proteins in fish tissue. Most fish have trace amounts of methyl mercury. The level of mercury found in fish is related to the level of mercury in its aquatic environment and its place in the food chain. Mercury tends to accumulate in the food chain, so large predatory fish species tend to have higher levels than non-predatory fish or species at lower levels in the food chain.
In freshwater fish
Levels of mercury in freshwater fish vary according to the lake, haur and beel or river system from which they are harvested, and as with marine fish, predatory species tend to have higher levels than non-predators. Most of the commercial, freshwater fishing areas in Bangladesh may contain a high level of mercury.
At this moment most of us don't need to be worried about mercury exposure as a result of fish consumption. In general, the types of fish that are most popular in Bangladesh are also relatively low in mercury. However, there are some types of fish that, if eaten too frequently, could result in exposure to an unacceptable amount of mercury.
International food standard guidelines recommend that a person can eat at least two servings (of 75 grams each) of fish a week. Children, pregnant and breastfeeding mothers and women who may become pregnant can particularly benefit from the nutrients offered by fish. However, because the developing fetus and young children are also most at risk from mercury exposure, it is important that pregnant mothers and breastfeeding women, women who may become pregnant and parents of young children are aware of what types of fish are a good choice for frequent consumption and which should be eaten less often.
Health Canada has identified certain fish as being of more concern when it comes to mercury levels. Fish can accumulate mercury in their muscles through absorption from the surrounding water but mostly from the prey that they eat. Thus and as previously mentioned, this mercury becomes more concentrated within higher levels of the food chain. - Author is an Ecologist and journalist
- NewsNetwork
