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6 Bioremediation of Pesticides Containing Soil and Water

United States Fish and Wildlife Service (USFWS) and United states Department of

Agriculture (USDA) estimation, US farmers face condensed crop cross-pollination

since the pesticides eradicate honeybee colonies [11].

Pesticide usage has been regulated in several countries through biodiversity action

plans due to their harmful effects on animals. For example, in England, increased

utilization of pesticides in farmland and gardens witnessed a decreased number of

chaffinches [12]. Food chain of species gets affected the most, since certain pesticides

bioaccumulate to toxic levels over time.

6.2

Pesticide Biomagnification and Consequences

Biomagnification is a cumulative rise in the concentrations of enduring substances

like metals and pesticides as they move up the food chain. Mercury, cadmium,

arsenic, and few pesticides such as polychlorinated biphenyls (PCBs) and DDT

are the major contributors [13]. The lower food chain organisms are prone to

the exposure of the toxins at a faster rate and when higher food chain organisms

consume them, the toxins get gathered [14]. Mechanism to sequester and defecate

metals is highly displayed by organisms that are subjected to greater levels of

exposure to metals. When organisms are imperiled to higher concentrations than

normal levels, it leads to difficulty in excretion of these metals and also portray

danger to the organism’s reproductive system [15].

Suedel and his co-group concluded that toxaphene, DDT, PCBs, dichlorodiphenyl-

dichloroethylene (DDE), and organic forms of arsenic and mercury will efficiently

bio-magnify in nature. The accomplishment of bird retrieval (bald eagles and

peregrine falcons) in North America was seen after imposing ban on DDT usage

in agriculture which proves the effect of biomagnification [16–18]. Herbicides,

fungicides, pesticides, and inorganic fertilizers will infiltrate into the soil and run off

in to rivers, ponds, and lakes through rains or natural calamities [19]. The industrial

effluents and agricultural wastes also have a major impact on biomagnifications [20].

In agricultural lands, the used pesticides which consist of toxic chemicals and

heavy metals will be captivated by zooplankton and plants. Once these are swal-

lowed by consumers, the chemicals are circulated into the body tissues leading to

hazardous health disorders. Algal blooms are caused by eutrophication which is due

to the excessive use of organic substances such as manures and biosolids in the fields.

They contain carbon, nitrogen, and phosphorous which act as causative agents in the

depletion of the aquatic animal’s oxygen leading to their death [2].

Pesticide’s toxicity is decided based on its dose and how long the chemical is

applied. Primary exposure of these pesticides to wildlife animals causes problems

during their nesting and nursing of young ones. Pesticides will reduce the insect pop-

ulation leading to destruction of food chain thus harming the entire vegetation [15].

6.3

Ill Effects of Biomagnification

In current years, the ingestion of seafood has been associated with few types of

cancer. This is due to the accretion of mercury and certain polycyclic aromatic