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Pesticide is a broad term for
insecticide, herbicide, fungacide
how are pesticides transported to streams and groundwater
runoff
wastewater discharge is the
most widespread cause of pesticide occurrence in streams and groundwater
runoff with pesticides kills organisms by going into the
drinking water
pesticides get into residential areas by getting
carried by wind and precipitation
pesticides are transported to groundwater by
recharge from rain or irrigation, leaky wall casings, and contaminated streams
groundwater is
important source of pesticides to some streams during low flow periods when ground water can be a major portion of streamflow
streams are
vulnrerable to pesticide contamination because runoff from agriculture and urban areas flows to streams with dissolved and particle associated pesticides.
problematic pesticides do what
kill nontarget species ex: bees and eagles
why use pesticides
reduce pests damage on crops, maximize yield, growing population, increase profit
pesticide cons
pesticide treadmill, artificial selection of resistant pests, persistence in the environment, harm/kill nontarget species
bt crops can kill what
non target species
bt crops make it so you have a
monoculture with limited genetic variety, can be more susceptible to danger, monoculture because of consistency of GMO product, loss of ancestral variety
bt crop pros
can be tailored to enviornment, can reduce pesticide use
bt crop con
can drive selection of pest resistent insects, loss of biodiversity, loss of ancestral variety
pesticide
Pesticides are substances that are used to control pests. They include herbicides, insecticides, nematicides, fungicides, and many others.
fungacide
attacks a fungus targeting a crop
herbicide
attacks weeds that compete for space
insects
attacks insects that target the crop
economic effects of pesticides
spend more and more on chemicals, stronger formulas probably more expensive. The farmer probably has to get through one bad crop season she realizes how much resistance there is to the insecticide ( loss of profit)
environmental/societal
how are companies ensuring that the pesticides arent harming the GI tract/health of the consumer? Stronger the pesticide the more likely it is to harm the microrganisms in the oils which is the microbiome of the soil. This leads to degreaded nutrient weak soil and groundwater contamination from persistant pesticides.
bioaccumulation
smaller organisms in the food web consume traces of pesticides in contaminated water and as larger predators consume huge quanities of smaller prey these chemicals get stored in the muscle tissue and then humans consume that muscle tissue (salmon, swordfish, tuna)
explain how regional transport of pesticides occur
drift in air in spraying or evaporating and traveling in wind and precipiation come down, precipitation/irrigation cna cause runoff pesticides to nearby wate rbodies or soil contaminating groundwater, soil erosion, animals can spread it biologically
bioaccumulation is when
top predators end up consuming the highest volume of chemicals. It can effecct embryotic development, neurological development etc.
meat production
raising of cattle, turkey, pigs, sheep, goats, or any livestock for consumption by humans
what does CAFO stand for
concentrated animal feeding operation
animal waste creates
lowered DO levels increase in turbidity, decrease in aquatic primary productivity, decrease in albedo so higher temp, increase in organic matter/nutrient load, eutrophication, increase in decomposition by aerobic bacteria
explain what happens when animal waste from CAFOs enter water
water is warming up because decrease in albedo, loses its ability to hold DO and at the same time aerobic bacteria eats the raw sewage and also consumes O2 so the DO decreases rapidly
poop spray is what
sometimes CAFOs use the manure to fertilize their fields if they are also growing crops, this can get into the air and travel away from the farm
what is the CAFO meat like/whats cafos like
usually fattier, fed cornmeal which isn’t natural food, cattle want grasses, chicken need corn seeds insects grains veggies worms, pigs want root veggies, grasses, seeds, mushrooms, these animals get very little exercise penned up in warehouse settings
explain a opposite of CAFO
free range, animals have access to open space and a more natural diet, lot of land, animals are healthier, get more exercise, meat is more expensive, animals are more prone to predator attacks and eating food that might be contaminated, farmer has to deal with that loss or pay more laborers to watch animals
cafo pros
more efficent means of production, uses less land
cafo cons
large concentrated areas of animal waste, possible water contamination possibility of infectious pathogen released into waterways, antibiotic/growth hormone use
overgrazing can happen from
free range
pros of free range
animals eat natural food sources, no preventative antibiotic use, waste spread over a larger area by fewer animals
free range cons
possible tragedy of the commons via overgrazing, soil degredation, water pollution, desertificiation, large land use per animal, higher cost for consumers than other methods
persistent organic chemicals also known as what
POPs
POPS dont easily break down why
because they aresynthetic carbon based, molecules like DDT and PCB
why can persistent organic pollutants be toxic to organisms
because they are soluble in fat awhich allows them to accumulate in organisms fatty tissues
why are chemicals more dangerous to children and pregnant women
they are fat soluble and developing baby in utero has high levels of fatty tissue as do young kids under 5
what are persistent orgaanic pollutants
persistent-dont break down, forever chemicals
organic-carbon based, often in rings with chlorine attached to the outside of ring
synthetic-lab produced
nonpolar- fat soluble, no partial changes
non polar means that it is what on the ring
evenly dispersed so soluble in fat because of electron distribution and absence of partial changes
DDT
pesticide, insecticide, colorless crystal, banned us sprayed to kill mosquitos, it accumulates in shells of eggs and they break before birds develop =, osprey most clearly effected
PCBs
industrial fluid, coolant for ars, yellow liquid, banned in us
POPs
persistant, organic, synthetic, cyclical with chlorine atoms, nonpolar
What do POPs contaminate
water and soil
What does rcra stand for
resource conservation and recovery act, governs disposal of waste
what does cercla do
comprehensive enviornmental response, compensation, and liability act, holds people responsible for cleaning up waste
biomagnification
increase in concentration of substances per unit of body tissuethat occus in sucessively higher trophic levels of a food chain or in a food web. DDT, mercury, and PCBs are substances that bioaccumulate and have significant environmental impacts
what do humans get from POPs
learining disabilities, kidney, liver dysfunction, damage to reproductive, circulatory system, nervous sytem,birth defects
mercury health defects
nervous sytem, speech vision and gate, muscle movement, corrodes skin, mucus membrane, chewing and swallowing
