Dear students, my name is Yordan Simeonov
and I would like in this video to present to you the story of pesticides
Pesticides are chemicals specifically manufactured to be toxic
to target organisms and pests and are deliberately introduced in the
environment in large amounts Jet without pesticides the modern development of
agriculture would be impossible and public health could in some cases
be compromised The extensive or improper use of pesticides can entail risks for
human health and non-target organisms and for the environment as a whole
The presentation includes an overview of the ways the pesticides work:
By blocking the cellular processes of the target organisms, By destroying or altering the pest metabolism,
By disrupting enzyme processes or denature proteins,
By simulating or interfering with hormones, By disrupting photosynthesis in weed plants
Short lists of the benefits of pesticides are also presented
and the hazards they pose to environmental media soil, water and air
and the adverse effects they could possibly cause to human health A special attention is drawn on
the worst industrial disaster in the history of the world related to
pesticide production It took place in Bhopal India by the release of carbaryl gas
in a factory of Union Carbide In the presentation the safe alternatives to
pesticides are also mentioned, as the implementation of the so-called
Integrated Pest Management, the introduction of biological control
methods and the biopesticides This is the title page for presentations
of the Erasmus project TOXOER Learning Toxicology through Open Educational Resources
And now let us go back on the topic and include some more detail
This is the classification of pesticides on the type of target organism
Herbicides are chemicals used to kill weeds,
Insecticides are used to kill insects, Rodenticides used to kill rodents
the multi-site fungicides and so on This is a photo of a crop duster
spraying pesticides Chemical or synthetic pesticides on the type of
chemical compound used Organochlorine: These are non-biodegradable
and persist in soil for a long time Organophosphorus: esters of alcohols with phosphoric acid
or other acids They are very toxic acetylcholinesterase inhibitors Carbamates:
they are derived from carbonic acid Mode of action is similar to organophosphates
Synthetic pyrethroids: insecticides which are esters of specific acids and alcohols
Organotin compounds, which are mostly three substituted
organotin compounds used as pesticides Organomercurial compounds, which
are the oldest group of fungicides used for seed dressing
Dithiocarbamate compounds, which have found a large application as fungicides
Some of their metabolites can create problems in the environment
Other groups of pesticides with limited application are the Benzimidazole, Chlorphenoxy and
Dipyridiliums compounds These are the basic modes of
action of pesticides: They block the cellular processes of the target
organisms in a purely mechanical way, They destroy or alter the pest’s metabolism,
They disrupt enzyme processes or denature proteins,
They simulate or interfere with hormones, They disrupt photosynthesis and prevent the weed plant
from producing or storing energy Here is a short list of the primary
benefits of pesticides They are used in public health programs to control
vector-borne diseases Pesticides are used to protect the stored food grains
They protect the standing crop in field They do not increase the crop yield like fertilizer
but by protecting the crop from pests They can be used also to
control household pests Let us consider the hazards of pesticides:
The pesticide industries cause pollution of soil, water and air Pesticides enter the food chain and
cause problems of bioaccumulation or biomagnification
Pesticides are not target-specific, hence also kill non-pest insects Pencicides can be highly toxic in nature
and can cause serious health problems like cancer, deformities and disease
Accidents in pesticides manufacturing units cause great loss of
human life Let us look at the safe alternative to pesticides:
Integrated pest management to pesticides or IPM is an environmentally-sensitive
approach that combines common-sense practices as use of pest-resistant
or tolerant species, predators and pathogens, Biological control methods
They use living beneficial organisms which are enemies and control pests
There are three components of biological control: importation, conservation and augmentation
Biopesticides: effective, unexpensive, cause no pollution
and pose no threat to human health They can be viruses, bacteria and funji
At the end of the presentation is the closing page of the presentations of the TOXOER project
where you can see the logos of the participating educational
institutions from seven European countries