ABUSES OF AGROCHEMICALS (Poisoning our future)

By

Muhammad Adil Class# 39

Muhammad Rabnawaz KhanClass# 03

Agrochemicals• Agrochemicals (pesticides and fertilizers) are looked upon as a vehicle for

improved crop production technology though it is a costly input. Balance use, optimum doses, correct method and right time of application of agrochemicals ensures increased crop production.

• Agrochemicals are the result of modern technology that depends on inorganic fertilizers and pesticides. Over use of these chemicals have severe effects on environment that may lead to an immediate and long term effects.

1905 1925 1945 1965 19850

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Use of Chemical Fertilizer during 20th century

nitrogenphosphoruspotassium

Year

Thou

sand

tonn

es

Source: B. McDuel, 1990. Chemicals on the farm

Agrochemicals• The current industrial agriculture system promotes the reliance on

agrochemicals, both synthetic fertilizers and pesticides, while neglecting to consider their negative effects on local communities, human health and the environment.

• The use of agrochemicals, has contributed enormously to the success of Green Revolution program globally, but with some noticeable pollution effects on ecosystem and human health (FAO, 1993).

Agrochemicals

• Fertilizers

• Pesticides

Fertilizers • Not all the nutrient ions in a fertilizer applied to a field soil are taken up

by the growing crop, and the fate of the remainder is very important in any discussion on the effects of their long-term intensive use.

• Three things can happen to these residues in the soil– They may remain in the soil– They may be removed in the water leaching through the soil or

running off the surface of the soil – They may be lost to the atmosphere by volatilization.• This loss of the nutrients from the soil can negatively

affect the environment in many ways.• The most commonly cited hazards are the

Crop damageFertilizer use at excessive rates has been known to have deleterious effects on crop growth. Examples are• The lodging of small grains and the low sugar content of sugar beets from

excessive N.• Nutritional disorders involving such trace elements as Zn and Fe incurred by

excessive P fertilizer and lime.• Damaging salt effects on seed germination and seedling injury from too

much soluble fertilizer salt adjacent to the seed row.• Acidifying action of excessive fertilizer N on soil and induced Al and Mn

toxicities.• Increased incidence of plant disease and pest attacks with excessive N, etc.• Too high level of N fertilizer is likely to lower the storage and cooking quality

of potatoes.

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Lodging due to excessive Nitrogen application

Damage to soil macro and micro organisms• It is possible to demonstrate the lethal effects of fertilizers and anhydrous

ammonia when applied in contact with a living worm. Of far greater significance to the earthworm is the greater supply or fresh organic material for its sustenance afforded through fertilization.

• Heavy use of N fertilizer is known to be inimical to the activity of symbiotic N fixing organisms. The legume plant well supplied with soil and fertilizer N is not a very efficient N fixer.

• Contention has also been made that fertilizer use, most particularly N, will inhibit soil’s capacity to nitrify N from the native organic matter source.

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Eutrophication• The term eutrophication describes the enrichment of surface waters with plant

nutrients. It is an unsightly process that degrades the aesthetic qualities of surface water bodies. Degradation may be in respect of excessive algal scum and aquatic weeds as well as undesirable color, taste and odor of the water.

• Agriculture is considered to be the major factor in the eutrophication of surface waters. Factors that trigger eutrophication process are Nutrients (N & P), a carbon source of CO2, favorable temperature and non-turbid water. If the latter three are favorable and nutrient concentration° reach 0.3 ppm N and 10 ppb P the algal and various water plant growths are likely to increased.

• A number of environmental scientists have claimed that the use of fertilizers on farm land has seriously increased the liability of inland water to become eutrophic, causing pollution in lakes and reservoirs both by the algal pigments becoming distributed in the water and by creating anaerobic conditions in the subsurface waters.

• Additional phosphorus may stimulate large blooms of algae, which do not naturally occur in abundance. Dense filamentous algal mats may form, changing the environment, excluding species and diminishing biodiversity.

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Harmful effects of Nutrients in water and food• Many factors of chemical, physical and biological character contribute to water

quality.

• WHO recommended standards for drinking water in Europe are: 0-11.3 ppm NO3 – N recommended, 11.3 - 22.6 ppm acceptable, and above 22.6 ppm not recommended.

• NO3 is being reduced to NO2 after ingestion, which combine with hemoglobin in the blood and produces methaemoglobin, reducing the capacity of the blood to transport oxygen (Methaemoglobinaemia).

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Harmful effects of Nutrients in water and food• Nitrate levels have similarly been established for various fresh vegetables and for

canned baby foods from natural sources as well as NO3 + NO2 in preserved fish and meats.

• The vegetables spinach, celery, lettuce and kale have a substantial capacity to accumulate nitrate as do such forages as sudan grass, annual grasses, immature cereals and maize cut for silage.

• Deficiency of Mg has been recognized as a major problem in the nutrition of cattle in many different regions of the world. Due to access of K.

• Excessive rates of P fertilizer have been known to cause substantial reduction in the above-ground concentration of such elements as Fe and Zn in plants.

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A pesticide is any substance or mixture of substances intended for preventing, destroying, repelling, or mitigating any pest.

“Pesticide” includes herbicides, fungicides, insecticides, or any other substance used to control pests.

Pesticides

Pesticides Risk

• Risks– Toxic to humans and animals– Impact on environment and ecosystem

Pesticides• Worldwide, about 3 billion kg of pesticides is applied each year with a purchase

price of nearly $40 billion year-1 (Pan-UK, 2003).

• Although pesticides are generally profitable in agriculture, their use does not always decrease crop losses.

• Most benefits of pesticides are based on the direct crop returns. Such assessments do not include the indirect environment and economic costs associated with the recommended application of pesticides in crops.

• To facilitate the development and implementation of a scientifically sound policy of pesticide use, these environmental and economic costs must be examined

Application (spray, dust,

etc.)

Air

Target pest

Surface water Sediment

Soil

Ground water

Emission

Emission

Drift

Deposition

HumansWild life

Plants

CattleCrops

Leaching

Aquatic organisms

Sedimentation

Drainage

Volatilization

Origin, Transport and FateDistribution routes and receptor organisms for pesticides use in agriculture

Harmful effect of Pesticides1 Public Health

• Acute Poisoning

– Worldwide, the application of 3 million metric tons of pesticides results in more than 26 million cases of pesticide poisonings (Richter, 2002).

– Of all the pesticide poisonings, about 3 million cases are hospitalized and there are approximately 220, 000 fatalities and about 750 000 chronic illnesses every year (Hart and Pimentel, 2002).

CANCER AND OTHER CHRONIC EFFECTS• Pesticides are carcinogenic and can cause chronic disorders. These major types of chronic health

effects of pesticides include– neurological effects– respiratory– reproductive effects– cancer.

• There is some evidence that pesticides can cause sensory disturbances as well as cognitive effects such as memory loss, etc (Hart and Pimentel, 2002).

• In addition to neurological effects, pesticides can have adverse effects on the respiratory and reproductive systems. For example, 15%of a group of professional pesticide applicators suffered asthma, chronic bronchitis (Weiner and Worth, 1972).

• Studies have also linked pesticides with reproductive effects. For example, some pesticides have been found to cause testicular dysfunction or sterility (Colborn et al., 1996).

• US data indicate that 18% of all insecticides and 90% of all fungicides are carcinogenic (NAS, 1987).

• Several studies have shown that the risks of certain types of cancers are higher in some people, such as farm workers and pesticide applicators, who are often exposed to pesticides (Pimentel and Hart, 2001).

• Many pesticides are also estrogenic – they mimic or interact with the hormone estrogen – linking them to increase in breast cancer among some women. The breast cancer rate rose from 1 in 20 in 1960 to 1 in 8 in 1995 (Colborn et al., 1996).

• Pesticides that interfere with the body’s endocrine–hormonal system can also have reproductive, immunological, or developmental effects (McCarthy, 1993).

• The negative health effects of pesticides can be far more significant in children than adults, for several reasons.– Higher metabolic rates in children– Children consume more foods

PESTICIDE RESIDUES IN FOOD• The majority of foods purchased in supermarkets have detectable levels of

pesticide residues.• For instance, of several thousand samples of food, the overall assessment in 8

fruits and 12 vegetables is that 73%have pesticide residues (Baker et al., 2003). • In five crops (apples, peaches, pears, strawberries, and celery) pesticide residues

were found in 90%of the crops. Of interest is the fact that 37 different pesticides were detected in apples (Groth et al., 1999).

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ENVIRONMENTAL COSTS OF PESTICIDESDomestic animal poisonings and contaminated products• In addition to pesticide problems that affect humans, several thousand domestic

animals are accidentally poisoned by pesticides each year, with dogs and cats representing the largest number

• For example, of 250 000 poison cases involving animals, a large percentage of the cases were related to pesticides (National Animal Poison Control Center, 2003).

• It is reported that 0.5%of animal illnesses and 0.04%of all animal deaths reported to a veterinary diagnostic laboratory were due to pesticide toxicities.

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• Pesticide residues are not only found in animal tissues but also in their products.

• For example, in Oahu, Hawaii, in 1982, 80%of the milk supply, was condemned by the public health officials because it had been contaminated with the insecticide heptachlor (Baker et al., 2003).

Destruction of beneficial natural predators and parasites

• In both natural and agricultural ecosystems, many species, especially predators and parasites, control or help control plant feeding arthropod populations. Indeed, these natural beneficial species make it possible for ecosystems to remain ‘‘green.’’

• Like pest populations, beneficial natural enemies and biodiversity (predators and parasites) are adversely affected by pesticides (Pimentel et al., 1993).

• For example, the following pests have reached outbreak levels in cotton and apple crops after the natural enemies were destroyed by pesticides.– Cotton bollworm– Tobacco budworm– Cotton aphid– Spider mites– Cotton loppers– European red mite– Red-banded leaf roller– Rosy apple aphid– Apple rust mite.

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• Fungicides also can contribute to pest outbreaks when they reduce fungal pathogens that are naturally parasitic on many insects.

• For example, the use of benomyl reduces populations of entomopathogenic fungi, resulting in increased survival of velvet bean caterpillars and cabbage loopers in soybeans.

• For example, from 1980 to 1985 insecticide use in rice production in Indonesia drastically increased the brown plant hopper due to the destruction of natural enemies (Oka, 1991). The estimated cost of rice loss in just a 2-year period was $1.5 billion (FAO, 1988).

Pesticide resistance in pests• The extensive use of pesticides has often resulted in the development and

evolution of pesticide resistance in insect pests, plant pathogens, and weeds.

• An early report by the United Nations Environmental Program (UNEP, 1979) suggested that pesticide resistance ranked as one of the top 4 environmental problems of the world.

• About 520 insect and mite species, a total of nearly 150 plant pathogen species, and about 273 weeds species are now resistant to pesticides (Stuart, 2003).

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Honeybee and wild bee poisonings and reduced pollination

• Honeybees and wild bees are vital for pollination of fruits, vegetable, and other crops. Bees are essential to the production of about one-third of US and world crops.

• Most insecticides used in agriculture are toxic to bees, pesticides have a major impact on both honeybee and wild bee populations.

• Mussen (1990) emphasizes that poor pollination will not only reduce crop yields, but also equally important, it will reduce the quality of some crops, such as melon and fruits.

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Crop and crop product losses• Basically, pesticides are applied to protect crops from pests in order to increase yields, but

sometimes the crops are damaged by the pesticide treatments. • This occurs when

(1) The recommended dosages suppress crop growth, development, and yield(2) Pesticides drift from the targeted crop to damage adjacent crops(3) Residual herbicides either prevent chemical sensitive crops from being planted(4) Excessive pesticide residue accumulates on crops, necessitating the destruction of the harvest.

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• When weather and soil conditions are inappropriate for pesticide application, herbicide treatments may cause yield reductions ranging from 2 to 50% (Pimentel et al., 1993).

• When residues of some herbicides persist in the soil, crops planted in rotation are sometimes injured.

• Crop injury and subsequent loss due to drift are particularly common in areas planted with diverse crops.

Ground and surface water contamination• Certain pesticides applied at recommended dosages to crops eventually end up in

ground and surface water as well as in rain water.

• The three most common pesticides found in groundwater are aldicarb, alachlor, and atrazine (Cornell, 2003).

• The main routes through which pesticides reach the water are: 1. It may drift outside of the intended area when it is sprayed.2. It may percolate, or leach, through the soil. 3. It may be carried to the water as runoff.

(States of Jersey, 2007).

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Fishery losses

• Pesticides are washed into aquatic ecosystems by water runoff and soil erosion.• Pesticides cause fishery losses in several ways.These include

– High pesticide concentrations in water that directly kill fish– The elimination of essential fish foods, like insects and other invertebrates.

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10 Wild birds and mammals• Wild birds and mammals are damaged and destroyed by

pesticides and these animals make excellent ‘‘indicator species.’’

• Deleterious effects on wildlife include – Death from the direct exposure to pesticides – Secondary poisonings from consuming contaminated food

which reduced survival, growth, and reproductive rates from exposure to sub-lethal dosages

– Habitat reduction through the elimination of food resources and refuges.

Wild life were destroyed by the use of agrochemical.

Microbes and invertebrates• Pesticides easily find their way into soils, where

they may be toxic to arthropods, earthworms, fungi, bacteria, and protozoa.

• Small organisms are vital to ecosystems because they dominate both the structure and function of ecosystems (Pimentel et al., 1992).

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• Agrochemicals as a management tool for optimum production practices had been a reality to increased yield and quality of Agriculture product.

• But a number of environmental pollution and health hazards have been associated with application of pesticides and fertilizers.

• The following recommendation and suggestion will decrease the detrimental effect and safeguard the use of agro-chemicals.

Precaution

Recommendation

i. Sales and use of pesticides must be legible to read the hazard and precaution for handling.

ii. Pesticides should be registered and recommended for use. iii.All chemical should store away from food stuff to prevent

accidental ingestion and contamination.

iv.Washing of sprayers and empty containers should be avoided in rivers, streams and near source of drinking water.

v. Use of personal protective equipment should be encouraged, reduce rate of inhaling fumes, gas dust and spray vapor.

THANKS