HEALTH RISKS FROM AGRICULTURE
Agriculture is defined as the rearing of plants and animals to produce food for
human use and consumption, animal consumption and raw materials for industry.
How and why did health risks arise from agriculture?
To meet the requirements, what did Caribbean countries have to implement?
Caribbean countries implemented the ‘Green Revolution’ which has been
beneficial but also hazardous to human health as well as marine life health.
Some benefits include the following:
● High input monoculture, using selectively bred all genetically engineered
crops
● high yields; using high inputs of fertiliser on water and extensive use of
pesticides (increased use of agrochemicals in commercial farming systems)
● multiple cropping systems, where there is an increase in the number of
crops grown per year on a plot of land
Health Risks caused by Mariculture:
● Mariculture produces high and sustainable yields at a low cost which
contributes to a stable industry. Unfavourably, high yields from Mariculture
leave behind significant amounts of bio-sediment. Bio-sediment is composed
of sediment particles, pores, and abundant biofilm that is embedded in the
particles. When the turbulence of the water in the sea suspends these
particles of sediment, it can negatively affect and even kill the organisms
being cultivated. Furthermore, the sediment can block the gills of fish and by
extension, reduces the metabolic activities of marine organisms.
● Since mariculture involves restricting the farmed fish population to a small
region of the sea, there is a build-up of organic matter in the water which
then ends up on the sea bed. Consequently, there is an increase in marine
worms and bacteria populations. When bacteria decompose the organic
matter, toxic gases are released into the water which would be detrimental
and fatal to marine life.
Consequences of the above benefits of the ‘Green Revolution’:
● Over-application of fertilizers - can increase pollution through runoff into
water bodies, infiltration of aquifers and evaporation into the air. The nitrates
and phosphates contents can cause detrimental health issues
● Waste runoff that increases nutrients and pathogens in the streams of water
And the runoff that carries sediments, nutrients and pesticides into streams can damage fish and other aquatic ecosystems and the organisms’ habitats
● There is an impact on native habitats and reduction of native biodiversity on
which communities depend on - for example, extensive commercial farming
has resulted in overexploitation and a reduction in the sea’s fish population
Major Health Risk caused by high inputs of fertilizers and waste runoff mentioned
above:
● The nutrients in inorganic fertilizers, especially nitrates, are water-soluble
and are dissolved by rainwater. After heavy rain, the run-off would contain
and carry these dissolved nutrients into other water bodies where it
encourages the growth of algae and plankton. This can result in a buildup of
toxins and eventually lead to the reduction of dissolved oxygen levels in the
water. This would be responsible for the death of marine organisms higher
up in the aquatic food chains/webs and ecosystems. Essentially,
eutrophication would occur from the water run-off in commercial
agricultural systems where there is an increased use of inorganic fertilizers.
● Solution- implementing an environmentally sustainable agricultural
practices like terracing or contour ploughing. With terracing on a hillside,
the terraces retain a great proportion of the water that would have run
downhill thereby reducing the volume of water runoff. This limits the risk of
soil erosion taking place. Likewise, with contour ploughing, the banks
created by the ploughing and planting of the furrows and crops delay the
flow of water downhill. The volume of water runoff from higher up the hill
and the speed of the water going downhill are significantly reduced. This
also minimizes the risk of soil erosion.
Further potential human and ecological health risks:
● Bioaccumulation - this occurs when a harmful substance (pesticides or
organic chemicals) gets absorbed by an organism at a higher rate than it can
be excreted. Bioaccumulation takes place in a single organism over the span
of its life, resulting in higher concentrations in older individuals.
● Biomagnification - the accumulation of a particular substance in the body of
the organisms at different trophic levels of the food chain. Biomagnification
takes place as chemicals transfer from lower trophic levels to higher trophic
levels within a food web, resulting in higher concentrations in apex
predators.
Pesticides in Paradise: Hawai'i's Health and Environment At Risk
PICTURE SHOWING POTENTIAL DISEASES AND SPECIFIC HEALTH
ISSUES OF HUMANS WHO ARE EXPOSED TO PESTICIDES
THE SOLUTION
Caribbean nations must make it their purpose and duty to incorporate human health
and well-being into agricultural systems while also preserving productivity levels
and environmentally sound practices.
For a healthy and productive lifestyle, sustainable agriculture should be redefined
to include sufficient nutritional output and "healthy foods."
Sources: adaptations from CAPE Environmental Science Unit 2 study guide, YouTube, other websites