Wednesday, April 23, 2008

Benzene contamination



Three weeks after discovery of contamination of water by benzene, producers solve ordering tests in private laboratories

More than three weeks after the disclosure of the first result that showed the presence of benzene above acceptable levels, the population of the West Lake and the government remain a race in search of more evidence of contamination. The Department of Environment and Water Resources (Semarh) waiting for tomorrow or after the arrival of 11 contraprovas. Eight samples were taken between Monday and yesterday in wells with suspected contamination, among them the asphalt plant, Etec, in Vila Baseví, and in three other nearby wells. Until tomorrow, the Association of Producers of the West Lake (Asproeste) collects the latest samples - a total of 50 - to send them to a private laboratory in Sao Paulo. The water of five condominiums of the Greater Colorado also passed through laboratory tests in Sao Paulo. The collections in lots will be made today.

The Secretary of Environment and Water Resources of the Federal District (Semarh), Antonio Gomes, does not recommend the demand by private laboratories. 'We must follow a scientific method, as well the empty three times before removing the water. This was done by a committee that collected samples for contraprovas. " The analyses are done by three laboratories: the Chemistry of the University of Brasilia (UNB) and two hired by the Company of Environmental Sanitation (Caesb) and Petrobras. Residents of the region seek other evidence because they believe that the results obtained so far do not reflect the reality. 'Collected only 23 samples and the West Lake has over 30km in length,' says the vice president of Asproeste, Jorge Medeiros.

Yesterday, the Semarh received the conclusion of other 11 analyses, collected before the contraprovas. The result was negative. The president of Caesb, Fernando Leite, believes that the contraprovas not indicate contamination. He has doubts whether the first analyses made by UNB, met the technical criteria appropriate. 'Is that the collection was the recommended way?' Questions. The responsible for analysing, Hugo Clemente de Araujo, a specialist in organic chemistry of UNB, was not located for comment on the statement.

The Central Supply of Brasilia (Ceasa) began yesterday to bar the entry of products from the West Lake to check whether they were produced in areas of risk. 'When the truck arrives, checamos if there is a report indicating contamination. If there is, release ', says President Marcos Lima. The producer Sergio Fayad, 50, was one of the disadvantaged. Over 90 boxes of fruit and vegetables were stops in his property, in block 18 in West Lake, until the release at noon. 'The problem is that the delay in delivery affect the quality of the product,' calls.

That is interditado

The Editorial

The Department of Environment and Water Resources of the Federal District (Semarh) banned the Auto Post Five Stars, located in Sector Hoteleiro North. The post was sealed by the bombs present problems in the system of environmental control. While the deficiencies are not resolved, the establishment will remain closed. Otherwise, you'll be charged a fine of up to $ 100 thousand.

According to the director of surveillance of Semarh, Flavio Braga, the clinic provides a series of failures. The floor is made of small blocks, is not proofed. There are channels around the courtyard of supply, used for collection of waste water containing fuel. 'This mechanism prevents the effluent to be absorbed by the soil,' said Flavio. Nor is there a box of water and oil separator system and the washing of vehicles is in the open. According Braga, the owner of the post, Sergio Vignoli, has already undertaken to remedy the deficiencies.

Vignoli ensures that the technical Semarh already knew the need for adequacy of the post. 'Postergamos the reforms because the post vai change of location. And that was already combined with the office ', said Sergio, though there is no provision for transfer of the post.

The risks from benzene

The acute poisoning can lead to death. In these cases most of the compound is retained in the central nervous system

By Carlos Gropen *

Chemical derived from oil, formed with six carbon atoms of hydrogen and six-shaped ring, C6H6, the benzene is used in various industrial processes. It has been replaced by other compounds because of their intense toxicity.

The benzene is one of the most well-studied chemicals, as the effects known carcinogens. You are well defined its role in the development of leukemia in humans. A small concentration of benzene in the human body, in the proportion of one part per million (1 ppm), can cause damage to bone marrow, producing region of blood cells - red and white blood cells. The reduction of red cells whose job is to transport oxygen, can cause anemia. Already the decrease in white blood cells leaves the body more susceptible to infections, because these cells are responsible for defending the body. In bone marrow is one of the worst potential effects of benzene, a leukemia. Other systems affected are the nervous system, endocrine and immune.

It is highly soluble in fat, the substance easily through the membranes of the body. You can cross the placental barrier in pregnant women and to accumulate in the blood of the umbilical cord of the foetus in quantities greater than or equal to that of the mother's blood. The risks to health, from exposure to benzene depend basically on three criteria: the concentration of the compound in water (quantity), the time of exposure to contaminated water and genetic predisposition, or some people are more likely to get sick as a result of poisoning than others.

Symptoms depend on the form of contamination. The acute poisoning is exposure to considerable quantities in a single episode, and chronic, is the body's contact with small doses over a long period of time. This second case applies in most of the conditions in which there is ingestion of contaminated water.

The acute poisoning by benzene can lead to death. In these cases most of the compound is retained in the central nervous system. Severe anaemia, euphoria, nausea, headache, arrhythmias and heart failure may also occur.

In cases of chronic poisoning, the benzene accumulates mainly in three locations of the body: bone marrow (40%), liver (43%) and the fatty tissue (10%). There is no specific symptoms, however the most common are nausea, weight loss, headache, fatigue, irritability and bleeding events. There is no specific drug treatment for cases of poisoning by benzene.

Carlos Gropen is a doctor and the Correio Braziliense consultant
carlos.gropenjr @

Correio Braziliense

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