The New Nation - Internet Edition

Untreated wastes cause serious health hazards

Md. Bashir Uddin Khan

An upcoming menace to the global environment Hazardous Wastes are solid, liquid, or gas wastes that can cause death, illness, or injury to people or destruction of the environment if improperly treated, stored, transported, or discarded. Substances are considered hazardous wastes if they are ignitable (capable of burning or causing a fire), corrosive (able to corrode steel or harm organisms because of extreme acidic or basic properties), reactive (able to explode or produce toxic cyanide or sulfide gas), or toxic (containing substances that are poisonous). Mixtures, residues, or materials containing hazardous wastes are also considered hazardous wastes. Many of the dangerous substances can be used only with special precautions that decrease their risks. When leftover, these substances are no longer under the direct control of the user and may pose special hazards to people or other organisms that come in contact with them. Because of such potential risks, hazardous wastes are processed separately from ordinary wastes.

Liquid waste that runs into a stream from a factory can kill wildlife and cause health problems for humans. Hazardous wastes are generated by nearly every industry; those industries that themselves generate few hazardous wastes nonetheless use products from hazardous waste generating industries. For example, in the computer software industry, writing software generates little hazardous waste, but the manufacture of computers involves many industrial processes.

Making a computer circuit board generates spent electroplating baths that contain metal salts, and the production of computer chips needs acids, other caustic chemicals, and solvents. Other hazardous wastes are generated in the manufacture of fiber optics and copper wire used in electronic transmission, as well as magnetic disks, paper for technical manuals, photographs for packaging and publicity, and trucks for transportation of the finished product. B Agricultural Wastes Not only industries but also agriculture produces such wastes as pesticides and herbicides and the materials used in their application.

Fluoride wastes are by-products of phosphate fertilizer production. Even soluble nitrates from manure may dissolve into groundwater and contaminate drinking-water wells; high levels of nitrates may cause health problems. C Household Wastes Household sources of hazardous wastes include toxic paints, flammable solvents, caustic cleaners, toxic batteries, pesticides, drugs, and mercury from broken fever thermometers. Local waste-disposal systems may refuse these items. If they are accepted, careful monitoring may be required to make sure soil or groundwater is not contaminated.

The householder may be asked to recycle or dispose of these items separately. Renovations of older homes may cause toxic lead paint to flake off from walls. Insulation material on furnace pipes may contain asbestos particles, which can break off and hang suspended in air; when inhaled, they can cause lung disease and cancer. D Medical Wastes Hospitals use special care in disposing of wastes contaminated with blood and tissue, separating these hazardous wastes from ordinary waste. Hospitals and doctors' offices must be especially careful with needles, scalpels, and glassware, called "sharps." Pharmacies discard outdated and unused drugs; testing laboratories dispose of chemical wastes. Medicine also makes use of significant amounts of radioactive isotopes for diagnosis and treatment, and these substances must be tracked and disposed of carefully.

Hazardous wastes may pollute soil, air, surface water, or underground water. Pollution of soil may affect people who live on it, plants that put roots into it, and animals that move over it. Sludge from municipal sewage disposal may contain toxic elements if industrial waste is mixed with domestic sewage. If the sludge is used as a fertilizer, these elements may contaminate fields. Toxic substances that do not break down or bind tightly to the soil may be taken up by growing plants; the toxic substances may later appear in animals that eat crops grown there and possibly in people who do so. Air may become contaminated by direct emission of hazardous wastes. Evaporation of toxic solvents from paints and cleaning agents is a common problem. The air above hazardous waste may become dangerously contaminated by escaping gas, as can occur in houses built on mine tailings or old dump sites.

River and lake pollution, if it is toxic enough, may kill animal and plant life immediately, or it may injure slowly. For example, fluoride concentrates in teeth and bone, and too much fluoride in water may cause dental and bone problems. Compounds such as dichlorodiphenyltrichloroethane (DDT), PCBs, and dioxins are more soluble in fats than in water and therefore tend to build up in the fats within plants and animals. These substances may be present in very low concentrations in water but accumulate to higher concentrations within algae and insects, and build up to even higher levels in fish. Animals having these fishes may be the bearer of high risk toxic substances that can happen a serious damage to their health. Underground pollutants can be carried by underground water flow.

These wastes form spreading underground plumes (long, featherlike columns) of contaminants, which may reach the surface if the water emerges in a spring or is pumped by wells. Especially dangerous are solvents that may have leaked from underground storage tanks or may have been carelessly poured on the ground. Toxic metal ions may also be present in these waste plumes.

Highly visible recycling programs reduce the overall amount of waste going into landfills, but those programs alone will not solve the garbage disposal problem. The article focuses on the challenges that face both countries as it becomes more difficult to market some recycled materials, and more expensive to open new landfills and incinerators.

A Source Reduction It may be the best way to use alternative materials in some industrial productions and thus it would be possible to reduce the poisonous impact of toxic substance to the nature. B Recycling Recycling is the recovery or reuse of usable materials from waste. About 5 percent of hazardous waste in the United States is recycled as solvents; a similar amount is recovered as metals. C Treatment Wastes may be made less hazardous by physical, chemical, or biological treatment.

For example, sodium hydroxide has been used to treat acid wastes at integrated-circuit plants. Some newer plants now treat hydrofluoric acid wastes with lime, producing relatively harmless calcium fluoride, the mineral fluorite. Sulfuric acid wastes, if not recycled, can be treated with ammonia wastes from the same plant, forming ammonium sulfate, a fertilizer. Incineration is the preferred method of handling infectious medical wastes. However, it should not be used for wastes that contain toxic heavy metals or chlorinated hydrocarbons: When burned, old painted surfaces can release lead or arsenic into the air, whereas chlorinated hydrocarbons produce hydrochloric acid and dioxins. Solids left over from incineration may have to be disposed of as hazardous waste.

Solidification of wastes involves melting them and mixing them with a binder, a substance that eventually hardens the mix into an impenetrable mass.

One suggested treatment of radioactive waste involves turning it into a glass through a process known as vitrification. Sometimes waste can be stabilized on-site; simple remedies such as covering the waste may be sufficient. Other stabilization methods involve building a barrier around the waste.

This barrier can be of plastic, steel, concrete, clay, or even glass. D Disposal Surface impoundment (placing liquid or semiliquid wastes in unlined pits) keeps waste in long-term storage, but it is not considered a method of final disposal.

A recent method of treatment for shallow plumes of chlorinated solvents depends on their chemical reactivity. A trench is dug around the leaking waste site and filled with a mixture of soil and powdered iron. The iron then reacts with the chlorinated solvents, turning them into simple hydrocarbons, which are less hazardous. As the hazardous wastes are not the problem of any single country but it is a matter of global panic, it is the duty of all the countries to take measures to control the emission of these substances by outlining laws and further research is essential for the hazardous waste management.

Bacteria toxin delivery may help find new antibiotics

Most bacteria are harmless and do not cause infections. Some, however, are pathogenic and are equipped with special accessories that are used to deliver toxins (also termed "effectors") into the cells of the infected person.

Numerous bacteria that cause disease, ranging from food poisoning to life threatening infection, employ a syringe-like nano-organelle (a specialized part of a cell having a specific function) that is used to inject toxic effectors into attacked host cells. This process is termed a type III secretion system (TTSS). Among these pathogens are Salmonella; the cause of typhoid fever, Yersinia; and enteropathogenic (intestinal) E. coli, which is responsible for the death of up to one million infants per year, mostly in developing countries.

The bacterial syringe employed by these bacteria is an excellent potential target for drugs (not yet available) to combat these diseases. In order to develop such drugs, however, a better understanding of the syringe functions is needed, requiring development of better methods for measuring the syringe activity.

The Hebrew University researchers -- Ilan Rosenshine, the Etta Rosensohn Professor of Bacteriology at the Hebrew University Faculty of Medicine, and his associates -- Erez Mills, Kobi Baruch, Xavier Charpentier and Simi Kobi -- have designed a new, real-time test that allows monitoring the syringe activity. Using this test, they have discovered new properties of this system, which might be used to develop drugs that will inhibit the syringe activity and thereby prevent disease and infection by these dangerous pathogens

Reference: Science Daily

Campylobacter Infection

Easir Abedin

Campylobacter is a bacterium that causes food poisoning. Most people who become ill with campylobacteriosis get diarrhoea, cramping, abdominal pain, and fever within 2 to 5 days after exposure to the organism.

The diarrhoea may be bloody and can be accompanied by nausea and vomiting. The illness typically lasts 1 week. Some people who are infected with Campylobacter don't have any symptoms at all. In people with compromised immune systems, Campylobacter occasionally spreads to the bloodstream and causes a serious life-threatening infection.

Campylobacter is one of the most common bacterial causes of diarrhoeal illness. Virtually all cases occur as isolated, sporadic events, not as a part of large outbreaks.

Campylobacteriosis (campylobacter infection) occurs much more frequently in the summer months than in the winter. The organism is isolated from infants and young adults more frequently than from other age groups and from males more frequently than females.

Diagnosis: Many different kinds of infections can cause diarrhoea and bloody diarrhoea. Doctors can look for bacterial causes of diarrhoea by asking a laboratory to culture a sample of stool from an ill person.

Diagnosis of Campylobacter requires special laboratory culture procedures, which doctors may need to specifically request.

Treatment: virtually all persons infected with Campylobacter will recover without any specific treatment. Patients should drink plenty of fluids as long as the diarrhoea lasts.

In more severe cases, antibiotics such as erythromycin or a fluoroquinolone can be used, and can shorten the duration of symptoms if they are given early in the illness. Your doctor will make the decision about whether antibiotics are necessary.

Duration: Most people who get campylobacteriosis recover completely within 2 to 5 days, although sometimes recovery can take up to 10 days.

Rarely, some long-term consequences can result from a Campylobacter infection. Some people may have arthritis following campylobacteriosis; others may develop a rare disease that affects the nerves of the body beginning several weeks after the diarrhoeal illness. This disease, called Guillain-Barré syndrome, occurs when a person's immune system is "triggered" to attack the body's own nerves, and can lead to paralysis that lasts several weeks and usually requires intensive care.

Outbreak: Campylobacteriosis usually occurs in single, sporadic cases, but it can also occur in outbreaks, when a number of people become ill at one time. Most cases of campylobacteriosis are associated with handling raw poultry or eating raw or undercooked poultry meat.

A very small number of Campylobacter organisms (fewer than 500) can cause illness in humans. Even one drop of juice from raw chicken meat can infect a person. One way to become infected is to cut poultry meat on a cutting board, and then use the unwashed cutting board or utensil to prepare vegetables or other raw or lightly cooked foods. The Campylobacter organisms from the raw meat can then spread to the other foods.

The organism is not usually spread from person to person, but this can happen if the infected person is a small child or is producing a large volume of diarrhoea.

Larger outbreaks due to Campylobacter are not usually associated with raw poultry but are usually related to drinking unpasteurized milk or contaminated water. Animals can also be infected, and some people have acquired their infection from contact with the infected stool of an ill dog or cat.

Source of Contamination: Many chicken flocks are silently infected with Campylobacter; that is, the chickens are infected with the organism but show no signs of illness. Campylobacter can be easily spread from bird to bird through a common water source or through contact with infected feces. When an infected bird is slaughtered, Campylobacter can be transferred from the intestines to the meat. More than half of the raw chicken in the United States market has Campylobacter on it. Campylobacter is also present in the giblets, especially the liver.

Unpasteurized milk can become contaminated if the cow has an infection with Campylobacter in her udder or the milk is contaminated with manure. Surface water and mountain streams can become contaminated from infected feces from cows or wild birds. This infection is common in the developing world, and travelers to foreign countries are also at risk for becoming infected with Campylobacter.

Prevention: There is some simple food handling practices for preventing Campylobacter infections. Physicians who diagnose campylobacteriosis and clinical laboratories that identify this organism should report their findings to the local health department. If many cases occur at the same time, it may mean that many people were exposed to a common contaminated food item or water source which might still be available to infect more people.

When outbreaks occur, community education efforts can be directed at proper food handling techniques, especially thorough cooking of all poultry and other foods of animal origin, and common sense kitchen hygiene practices. Some data suggest that Campylobacter can spread through a chicken flock in their drinking water. Providing clean, chlorinated water sources for the chickens might prevent Campylobacter infections in poultry flocks and thereby decrease the amount of contaminated meat reaching the market place.

Some Tips for Preventing Campylobacteriosis

*Cook all poultry products thoroughly. Make sure that the meat is cooked throughout (no longer pink), any juices run clear, and the inside is cooked to 170oF (77oC) for breast meat, and 180oF (82oC) for thigh meat.

*If you are served undercooked poultry in a restaurant, send it back for further cooking.

*Wash hands with soap before handling raw foods of animal origin. Wash hands with soap after handling raw foods of animal origin and before touching anything else.

*Prevent cross-contamination in the kitchen:

*Use separate cutting boards for foods of animal origin and other foods. Carefully clean all cutting boards, countertops and utensils with soap and hot water after *preparing raw food of animal origin.

*Avoid consuming unpasteurized milk and untreated surface water.

*Make sure that persons with diarrhoea, especially children, wash their hands carefully and frequently with soap to reduce the risk of spreading the infection.

*Wash hands with soap after having contact with pet faeces.

(Easir Abedin, M.Sc Microbiology (D.U),MBA Assistant Manager Quality Control NOVO Healthcare and Pharma Ltd.)

Jackfruit is a good source of carotene

Jamayet Ali

Jackfruit is familiar to us as the largest fruit in the world. It is the national fruit of Bangladesh and bears a good source of carotene equivalent to vitamin 'A'. It is a large tropical fruit- tree, with a dense crown reaching a height of at least 30 feet or more. The straight, cylindrical stem is covered with rough bark which excludes milky latex. The plant is indigenous to Bangladesh and India. It is also grown in Sri Lanka, Myanmar, Malayasia, and Brazil and has been introduced into many other tropical countries. The tree is a good shade-bearer, but thrives best in the open. The fruits are borne in the trunk and on the main branches. The tree bears fruit in about eight years. For successful cultivation, it requires a moist tropical climate and a deep rich soi1. Owing to its long delicate taproot, seedlings cannot be easily transplanted. Seeds are therefore sown during ramy season.

Botanical name of jackfruit is Artocarpus integrifolia. The fruit contains a large number of seeds, each enclosed in a yellowish juicy sheath and sweet substance, which, if fermented and distilled, yields an alcoholic beverage, with a strong odour and peculiar flavour. The seed, when roasted, is eaten as an article of food, and is said to resemble chestnuts. When ground to flour it very much resembles the top quality of wheat flour. The fruit when unripe is cut into small pieces and cooked in curry with shrimps. It becomes very tasty to eat. The seeds of the ripe fruit, when roasted in hot ashes, are very palatable and nutritious. Two common varities of jackfruit are generally available in the market. One is very sweet, fleshy and crisp peri carp, and the other that is considered inferior, has a thin mucilaginous and sour pericarp.

High quality of jackfruit grows in the areas of Savar, Narshingdi, Joydevpur of Dhaka, Jessore, Khulna and Satkhira. The wood is yellow when freshly cut, but gradually turns light brown on exposure. It is fairly strong, durable, and not attacked by fungi or white ants. The wood is cheap and of excellent quality, suitable for general carpentry work and plain furniture, for brush backs, inlay work and turnery. It is also a favourite wood for musical instruments. The timber has a local demand, but the tree being mainly grown for the fruit, is not available in commercial quantities.

Edible per 100grms. green jackfruit contain: moisture, 84.0; mineral matter, 0.9; fibre, 2.8; calorie, 51 (kilo); protein, 2.6; fat,0.3; carbohydrate, 9.4grms. calcium,30; iron, 1.7; vitamin B-l,0.05; vitamin B-2, 0.04; vitamin C, 14 mg. Ripe jackfruit contains: moisture, 88.0; mineral matter, 1.1; fibre, 0.2; calorie, 48 (kilo); protein, 1.8; fat, 0.1; and carbohydrate, 9.9grms.; calcium, 26; iron, 0.5; carotene (vitamin A) 4,700 IV; vitamin B-l,0.11; vitamin B-2, 0.15; and vitamin C, 21mg./100g. The seeds which form about 5.1 % of the fruit are rich in starch. They contain moisture: moisture, 51.6 ; protein, 6.6 ; fat, 4.4; carbohydrate, 38.4; fibre, 1.5; mineral matter, 1.5; calcium, 0.05; phosphorus, 0.13%; Fe, 1.2 mg/100g. (Food Processes and Analyses, Mohammad Yunus, Bangladesh Agricultural Research Council, Dhaka,47, 49; Wealth of India,Raw Materials, Vol.-l, 126)

Medicinal Properties: The unripe fruit is acrid; carminative, tonic; useful in "kapha". -The ripe fruit is cooling, oleaginous; tonic, fattening, aphrodisiac; useful in biliousness, "vata", leprosy, ulcers; causes "kapha". - The seeds are sweet; diuretic, aphrodisiac, constipating (Ayurveda). The young leaves are fomentation are applied to boils and wounds to dry them. - The fruit is sweet with a pleasant taste; tonic, aphrodisiac; enriches the blood. - The seeds are aphrodisiac (Yunani).

The juice of the plant is applied externally to glandular swellings and abscesses to promote suppuration. The tubers, if worn on the waist, are said to cure hydrocele. The young leaves are used in skin diseases, and the root is used internally in diarrhoe, The leaves are considered an antidote to snake-poison. They enter in a compound Munda medicine drink to stop vomiting The unripe fruit in astringent, the ripe laxative, but rather difficult to digest, although very nutritious.

The leaves are not an antidote to either snake-venom (Mhaskar and Caius) or scorpion-venom (Caius and Mhaskar). In Cambodia, the wood is considered a nervous sedative, and is administered in convulsions. The pith is taken internally as an abortifacient. (Indian Medicinal Plants, Kirtikar & B.D. Basu, 2337)

Medicine: The juice of the plant is applied externally to glandular swelling and abcesses to promote suppuration. The young leaves are used in skin diseases, and the root internally in diarrhoea. "This is an important article of food, both when green as well as when ripe. The seeds contain a quantity of starchy matter, which may be separated by drying and pounding them. The unripe fruit is astringent, the ripe laxative, but rather difficult to digest, although very nutritious. The juice of the plant is use to promote absorption of glandular swellings" (Surgeon D. Basu, Faridpur, Bengal) (Dictionary Of The Economic Products Of India, Vol.-i, 332)

Properties and Uses: The unripe fruit is acrid, astringent, carminative and tonic; ripe fruits are nutritious and laxative; seeds diuretic. latex is applied to glandular swellings and abscesses to promote suppuration. Leaf ash is useful in healing ulcers. Young leaves and roots are useful in skin diseases, asthma and diarrhoea (Medicinal Plants of Bangladesh, Second Edition, Abdul Ghani, 113).