Body Burden- Pesticide residues

Download Body Burden- Pesticide residues

Post on 22-Jan-2015

725 views

Category:

Health & Medicine

3 download

Embed Size (px)

DESCRIPTION

Pesticides are important input to modern agriculture and also used in public health in controlling communicable disease.The toxicity of these compounds poses risk to human health, environment and to the organisms which may not be targeted by pesticides.The effect of pesticides and their mobility depend upon their chemical and physical properties, soil characteristics, groundwater infiltrations and vadose zone behaviour, vegetation and local weather conditions. They resist degradation by chemical, physical or biological means.There is no sort of lower standard or different standard used for pesticide products, says Angus Cameron, a former manager of the firm Inveresk Research International in Scotland, where many of the human tests have been conducted.

TRANSCRIPT

<p>Pesticide Residues Impact on Health and Detection </p> <p>Pesticides are important input to modern agriculture and also used in public health in controlling communicable disease. The toxicity of these compounds poses risk to human health, environment and to the organisms which may not be targeted by pesticides. The effect of pesticides and their mobility depend upon their chemical and physical properties, soil characteristics, groundwater infiltrations and vadose zone behaviour, vegetation and local weather conditions. They resist degradation by chemical, physical or biological means. There is no sort of lower standard or different standard used for pesticide products, says Angus Cameron, a former manager of the firm Inveresk Research International in Scotland, where many of the human tests have been conducted.</p> <p>Pesticide residues present in food are due to: </p> <p> Direct use of pesticide on the food crop; animal feeding on pesticide contaminated feed; environmental contamination and Adulteration.</p> <p>The total intake of organochloride pesticides such as DDT, aldrin,dieldrin, hexachloro benzene etc.,through food is 223 microgrammes per person per day in India. In comparison the same is only 3.8 microgrammes per person per day in the United States. Most fruit and vegetables are grown using pesticides. Their widespread usage is causing health problems due to residues of pesticides in food and pollution of drinking water.</p> <p>The most worrying types of chemicals are those which are hormone disrupters and which can build up inside the human body. Hormone disrupters interfere with our bodys hormones. Our hormones regulate our day-to-day bodily functions and are vital for making sure we grow up healthy.</p> <p>Some chemicals that we cant break down properly will accumulate in the bodys tissues. This is known as bioaccumulation. Safeguards for pesticides in food do not contain much-needed special protections for infants and children. Instead they are geared to the average person in the population. Organophosphates, tend to break down so rapidly that they are unlikely to show up on food unless applied to crops very close to harvest time, but they are often more acutely toxic. In India, a 7-year study showed that organochlorine residues were above the tolerance limits in more than 35 percent of the food. While exported foods are usually monitored carefully so that they will pass the inspections locally marketed foods are usually not monitored, yet these are most likely to have residues of the short-lived, highly toxic organophosphates because of the short time between harvesting and marketing. </p> <p>Eating safe means calculating what we eat, how much we eat and how much pesticide can be allowed in what we eat. The food basket is also our pesticide basket. We have to ingest pesticides because we need nutrition, but we must not exceed our quota of pesticides that is allowed or acceptable. You can call this the nutrition-poison trade-off. So long as we cannot wish away pesticide use, it is imperative that this trade-off is a prudent one. But if the food has no nutritive value and carries poisonous pesticides with it, consuming even the smallest possible amount would be unsafe because the body will only get the poison and not its antidote, the nutrition. This is the whole logic behind pesticide health risk management. Currently, the pesticide intake through an Indian diet exceeds the ADIs of the commonly used pesticides. </p> <p>Maximum Residue Levels of Pesticides in Food </p> <p>1. In order to protect the health of the consumer while facilitating international trade, the Codex Alimentarius Commission (Codex) has established Maximum Residue Limits (MRLs) for individual pesticides in selected commodities. MRL is the maximum concentration of a pesticide residue to be permitted in a food commodity. The primary objective of setting MRLs is to protect the health of consumer by ensuring that only the minimum amount of pesticide is applied to food for achieving the actual pest control needs. </p> <p>2. Codex MRLs are established on the basis of appropriate residue data obtained mainly from supervised field trials. Supervised trials are scientific studies in which pesticides are applied to crops or animals in the way which is intended to reflect commercial practice according to Good Agricultural Practice (GAP). GAP in the use of pesticides includes the authorised safe use of pesticides under actual conditions necessary for effective and reliable pest control and in a manner which leaves a residue which is the smallest amount practicable. </p> <p>3. Even though the primary purpose of setting MRLs in food is to protect the health of consumers and the levels are intended to be toxicologically acceptable (i.e. do not cause acute or chronic toxicities in humans), it should not be confused with safety limits which are expressed in terms of the Acceptable Daily Intake (ADI) of a particular pesticide residue from all sources. It follows that exposure to pesticide residues in excess of MRLs does not automatically imply a hazard to health. Instead, a residual level exceeding the MRL is more a reflection for non-compliance to GAP. </p> <p>4. for some pesticides that have been banned or are no longer in use, trace amount of their residues and metabolites may be present in food as environmental contaminants because of their persistence in nature. Codex has established "extraneous maximum residue limits" (EMRLs) for some of these persistent pesticides. EMRL refers to residues of compounds, once used as pesticides but are not any more registered as pesticides, arising from environmental contamination. Pesticides Detected</p> <p>Pesticides have been found in human blood, urine, breast milk, semen, adipose</p> <p>tissue, amniotic fluid, infant meconium and umbilical cord blood. Cumulative exposure to pesticides</p> <p>may come from food, water, air, dust, soil etc. Pesticides can be absorbed through skin contact,</p> <p>inhalation or accidental ingestion. Organochlorine and Organophosphorus pesticides are most commonly found Food residues.</p> <p>Permissible limits in Human body</p> <p>Depending on the nature of individual pesticide, the amount and duration of exposure, pesticides exceeding safety limits may cause acute and/or chronic effects in humans. 1.Adverse health effects include damage to nervous system or other organs such as the liver and kidneys. Some may be transferred via the placenta or breast feeding, thereby affecting the foetal development. 2. The ADI of a chemical is the estimate of the amount of a substance in food or drinking-water, expressed on a body-weight basis, that can be ingested daily over a lifetime without appreciable health risk to the consumer on the basis of all the known facts at the time of the evaluation. 3. A dietary intake above the ADI does not automatically mean that health is at risk. Transient excursion above the ADI would have no health consequences provided that the average intake over long period is not exceeded as the emphasis of ADI is a lifetime exposure. </p> <p>So how safe is the food?"Food safety" implies absence or acceptable and safe levels of contaminants, adulterants, naturally occurring toxins or any other substance that may make food injurious to health on an acute or chronic basis. We are what we eat. Our nutritional status, health, physical and mental faculties depend on the food we eat and how we eat it. Food contamination can take place at various stages of the food chain from farm to table. Apart from chemical contamination of food from various sources such as industries, vehicles, pesticides and fertilizers, pollution resulting from growing of vegetables in degraded environmental conditions in peri-urban zones also affects food safety. This is coupled with further pollution from vehicles and industries during marketing. The common sources include presence of heavy metals, pesticides, preservatives, colouring agents and other additives and adulterants in food. </p> <p>Pesticide: a Lurking MenaceIndia uses about 30,000 tons of pesticides a year, more than 60% of it on food crops. Use of excessive pesticides contaminates soil, water and finally enters the food chain and contaminates the food produced. About 20% of Indian food products contain pesticide residues above the tolerance level compared to only 2% globally. No detectable residues are found in only 49% Indian food products compared to 80% globally. The UNEP estimates accidental pesticide poisoning causing 20,000 deaths and 1 million cases of illness per year worldwide. Pesticides have been implicated in human studies with leukemia, lymphoma, aplastic anemia, soft tissue sarcoma and cancers of the breast, brain, prostate, testis and ovaries. The International Agency for Research on Cancer has found "sufficient" evidence of carcinogenic potentiality in most of the pesticides beyond the threshold limit.</p> <p>Impact on crossing safe limit DiseasesThe prescribed Acceptable Daily Intake (ADI) and Maximum Residue Limit (MRL) for India is being determined based on the recommendation of the Codex Committee on Pesticides Residues (CCPR) a subsidiary body of the Codex Alimentarius Commission. Acceptable Daily Intake or ADI is a measure of the amount of a specific substance (usually food adititive or pesticide) in food that can be ingested (orally) over a lifetime without an appreciable health risk. Without appreciable risk" refers to the practical certainty that injury will not result, even after a lifetime of experience. ADIs are expressed by body mass, usually in milligrams (of the substance) per kilograms of body mass per day. The concept of ADI was first introduced in 1961 by the Coucil of Europe and later the Joint Expert Commiitee on Food Additives (JECFA), a commiitee maintined by two United Nations bodies: the Food and Agricultural Organisations and WHO. </p> <p>Maximum Residue Limits or MRL for pesticides are established in most countries to safeguard consumer health and to promote GAP in the use of insecticides, fungicides, herbicides and other agricultural compounds. MRL is the maximum concentration of a substance, expressed in milligrams per kilogram (parts per million, ppm) or in micrograms per kilogram (parts per billion, ppb) that is legally permitted in a food commodity. An MRL is typically applied to a veterinary drug or a pesticide and is established for particular food commodities such that potential consumer exposure to residues is judged to be toxicologically acceptable. The MRL set for a substance may differ for different food commodities, reflecting the contribution of the particular food to a "standard" diet. Normal intake of food containing residue of a substance at its MRL is not expected to result in the ADI being exceeded. </p> <p>Reasons for more Pesticide residues in India </p> <p>The pesticides are used improportionately in India in relation to places and the amount of pesticides residue varies from one place to another. Tamil Nadu consumes 1.2-2.0 kg/ha of land followed by Andhra Pradesh and Punjab where 0.8-1.2 kg is the rate of consumption. Pesticide residues in the feed and fodder are solely responsible for their accumulation in animal and poultry. The states like Tamilnadu, AP, Punjab, Haryana, and Karnataka have highest use of pesticides in order to get more production while on the other hand the states like Bihar, West Bengal, North eastern states have lowest use of pesticides. It is because of illiteracy of farmers, poor economic conditions or due to lack of awareness. So the food commodities in high using states have more residues of pesticides. </p> <p>Status of pesticide residues in India The presence of pesticide residues have been detected in various items and in food chain. The levels of the pesticides are found much higher than expected because of heavy contamination of environment. Besides, there are human milk, fat or tissue samples screened for the presence of pesticide residues were also found to have very significant levels of harmful pesticides. The BHC has been found from 0.120 to 1.22 PPM in human fat samples. Heptachlor, an organochlorine pesticide was found to be 0.425 PPM and DDT from 0.195 to 1.695 PPM. Even human breast milk is not free from DDT, which was found to have even 2.39 PPM levels. Similarly human blood was found to have a much higher concentration of 12.00 PPM as against of 0.050-PPM safe levels (no effect levels). </p> <p>Another classification of pesticides from the World Health Organisation, is as per their acute toxicity. This classification includes Class I a Extremely hazardous, demarcated in red; Class I b Highly Hazardous, symbolized by an yellow triangle; Class II Moderately Hazardous, marked by a blue triangle; Class III is known as Slightly Hazardous; while the remaining class is supposed to be Not likely to be Hazardous. It is to be noted here that two thirds of the pesticides consumed in India fall under WHO Class I and II pesticides. Between 1965 and 1998, the contamination of food from pesticides in India has been estimated at only 41% being free from residues, as compared to 63% being free from residues that 20% of the contamination is above fixed Maximum Residue Limits [MRLs]. In the EU, this is estimated to be only around 1.4% while in the USA, in 1996, it is reported that the contamination above MRLs was around 4.8%. In the 1980s, the All India Coordinated Research Project on Pesticide Residues (AICRPPR) was set up to monitor pesticide residues all over the country.In 1999, the AICRPPR reported that, with all commodities put together, 20% of the food samples tested exceeded the MRLs. Fruits, vegetables and milk are found to be highly contaminated. Monocrotophos, Methyl Parathion and DDVP, all organo phosphorus pesticides, are found to be most prevalent. These are also WHO Class I pesticides.</p> <p>The pesticide detection rate for green leafy vegetables during winter months was 53.3% as compared to</p> <p>those of rainy (8.3%) and summer months (23.1%). Corresponding figures for non-leafy vegetables were 30%, 12.5% and 19.5%, respectively (Mukherjee D, 1980). In a response to a starred question (No. 202) in the Indian Parliament on 8/8/2005, the Agriculture Minister revealed the following information: Statement indicating the extent of pesticide residues in various agricultural commodities Monitored under All India Network Project on Pesticide Residues On Vegetables (cabbage, cauliflower, brinjal, okra, potato, beans, gourds, tomato, chilli,</p> <p>Spinach, carrot, cucumber, cowpea etc.)</p> <p>Year No. of Samples analysed Samples above MRL (%)1999 277 10 (3.6%)2000 712 81 (11%)</p> <p>2001 796 93 (11.7%)2002 592 54 (9%)2003 666 35...</p>

Recommended

View more >