In major or measured minor the mass media have become echo of the dengue epidemic (1) that sole to our country. However beyond enumerating the cases by province and the consequences on the health, the practices to eliminate domiciliary centers of water and on the advance of the fumigations little go deep on the causes of this phenomenon and what is more important on the consequences that the massive fumigations can have on the health of the communities affected by dengue and these pulverizations, the majority of the realized times of unscrupulous way, that is without considering the surroundings of where they are realized.
1 – Which can be the causes of the expansion of the disease?
The causes are multiple but they are related to each other. As the progress of the disease is known has to do with the expansion of the zones of distribution and the possibilities of survival of the mosquito Aides Egypt, both are related to the effective agricultural model and the climatic change, these as well tie to each other.
Although it is possible to speak of the multicausality of the diseases is doubtless that the productive model based on the monoculture of transgenic soybean, the use of weed killers, fungicides and insecticides owns its impact in the rate reproduction and survival of the vector.
In the first place the deforestation and burning fire of forests and I mount, to dedicate earth to the soybean culture, has determined the migration of the mosquitoes towards other zones where they have found optimal conditions for its survival. In this case also it owns a remarkable one especially influences the climatic change the elevation of the temperatures and the change in the conditions of humidity.
The embryonic eggs can resist extreme temperatures staying viable enters 7 months a year (Alimony, W, 2006) (2).
Since in themselves monocultures are insustentables require the increasing insecticide use and weed killers with what not only hits in the survival of the insects but in the one of their natural enemies.
2 – How is related the use of pesticides to the conditions of survival of the insect?
On the one hand the use of pesticides especially the insecticides 2, 4 D and Glifosato and of insecticides as the Endosulfan hits in the development of the natural enemies of the mosquitoes, in this case toads and fish that devour so much to larvae as to adult insects. These pesticides can hit directly like thus also bringing about alterations in their embryonic development (3) and the nervous system, altering their possibilities of survival. Investigations even exist on alterations in the immunological system of these animal related to the increase in the concentration of pesticides in the water of rivers, pools and lagoons. In this case that immunological alteration returns more vulnerable them in front of bacteria and parasites.
A study realized on water obstacles in the province of Buenos Aires (Augustine, 2005) (4) has verified the impact of the mixtures of pesticides on the survival of amphibians. Especially the effects are important on the stages initiates to them of the life of these organisms, larval state. The nonmetal impact can have consequences on the conditions of growth and development of these organisms.
On the other hand the increase in the application frequency as thus also in the doses of these products it determines the appearance of genetic resistance. This way whatever more chemicals are used more resistance acquire the insects. Resistance that is transmitted to the future generations of the insect. This resistance can have one double modality:
to the capacity of the insect to detoxificar – to break, to unfold the molecule of the pesticide transforming it into a less dangerous substance and
b the possibility of generating a exoesqueleto – external protection of the insects lasts more consequently is more difficult that the pesticide penetrates in the body. In both cases, and following the Darwinian conception, of which most apt they survive, in a few generations all the mosquitoes develop resistance. In this situation the normal doses of the pesticide become ineffective. By generating the increase in the doses, the spare part by toxic products but and even the increase in the application frequency; they only reinforce the problem.
3 – The extension of the zone of distribution of the mosquito is related to the climatic change?
It is possible to be affirmed yes that. The climatic change that is pronounced from an elevation of the temperature and the conditions of humidity has caused so much the extension of the zone of distribution like the increase of the number of annual generations of the mosquito and therefore better conditions for the expansion of the disease. However the climatic change has not happened naturally or by chance, on the contrary so much to the increase in the industrial activities, the transports is related, the burning fire of forests that generate carbon dioxide like with the reduction in the surface covered by trees, that absorb that compound. Again we found a relation between the model of agricultural production and the expansion of the disease.
4 – Is effective the use of pesticides to diminish the populations of the mosquitoes?
The experience demonstrates that used separately they do not solve the problem. In the first place one is due to consider that the diseases transmitted by vectors are influenced by multiple elements and that to center the strategies of control in the chemical attack of the vector a restrictive and ineffective approach is. By the contrail it is required to take the problem from holistic and systemic way being incorporated elements of order social, geographic, environmental and cultural in the handling strategies (Souza Casadinho, J. 2007) (5).
The pesticides only can end the larvae or the adults who are reached in the applications, but as already it were mentioned the insects can acquire resistance.
In addition the mosquitoes, although do not disperse to great distances, can reach the 800 meters in their flights (Alimony, W, 2006) (6). In this case the adults who not reached about the pesticides, can distribute themselves in the atmosphere.
5 – the used pesticides own impact in the health of the people?
If. Although the present one like of “low impact”, “innocuous” “friendly with the people “, the used toxics can present/display impacts in the health of the population reached directly or by indirect route from the contamination of the water, foods, clothes, etc.
In this case one is due to emphasize that the pesticides are classified according to their specific toxicity – potentiality to cause damage in five categories, from the extremely dangerous ones to the products that “practically do not offer danger”. Very not very often in their categorization the social and environmental conditions of application consider, which can return very dangerous to a product class IV (that normally does not offer danger) (Souza Casadinho, j. 2005) (7).
One is due to stand out that sometimes the fumigations are realized without notifying the affected communities consequently the same are exposed to particles of the toxic (8). Besides being contaminated the water sources, pools, rain tanks, etc.
The damages in the health of toxics used in the campaigns against dengue, generally pesticides that own protrude chemical classification, can be pronounced quickly, acute symptoms or by the contrail to pronounce itself much later of happened the contact, chronic symptoms.
Being the acute symptoms are; the creeps in the eyelids and the lips, irritation in the eyes and the mucous, estornudos, vomits, chill. Between the chronic symptoms they are, blisters in the skin, inflammation in the lungs, hormonal disruption. (9, 10, 11)
6 – Exists a correct or safe application?
No. Although like in the application of any technology, the risk can be reduced during the application, are so many the variables that are due to consider that the safe use is very little probable to take to the practice. In the pesticides the case of investigations occurs on effectiveness, use security and approval in ideal situations – the laboratory – soon to be applied in real situations, in which the economic conditions – the pressure of the market, the climatic conditions, the access to the information usually influences in the true conditions of use.
The pesticides are applied without an suitable knowledge of their danger, of hardship, with people realizing tasks in the environs. The divided product sale, the little existing information in the labels, the nonexistence of protective equipment, the nonexistence of effective qualification of applies those who them, is to clear the best evidence from than the recommended conditions of use are not taken to the practice.
7 – He is advisable to fumigate the interior of the addresses?
It is a very dangerous technique of control since the pesticides can reach the water sources, the clothes, foods, the cupboards, the tables, the chairs, etc., consequently can indirectly reach to the people inhabit who them. In this case the particles of the pesticide can be adhered by a time interval to diverse domestic equipment causing health problems to those who ingest, touch or use the contaminated elements.
In addition, as generally doses of application are used higher than the recommended ones, the danger in its use is increased (Souza Casadinho, Javier, 2005) (12).
8 – Which can be the strategy to prevent dengue?
It is obvious that the conditions of house, sanitary infrastructure and environmental cleaning constitute factors of importance in the conditions of life and reproduction
