For example, because algae, which are needed for coral reefs to thrive and keep their color, easily leave an environment if temperatures increase/decrease too much
8.3 Endocrine Disruptors
Endocrine systems
The hormonal systems of organisms
When pollutants from human activity are introduced to the endocrine system of a population, that population may experience gender imbalances
Organisms may have a lower sperm count than they normally would
When nutrients, such as phosphorus or nitrate, become too excessive in a body of water and cause algae to overgrow
This is bad because the algae can block light and prevent it from reaching organisms under the surface of the water
Dissolved oxygen
Oxygen that has been dissolved into the water and is available for organisms underwater to use
When algal bloom occurs, and as the abundant amounts of algae die off, decomposers must consume a lot of the available dissolved oxygen in order to decompose that dead algae
This means that there is less dissolved oxygen available for fish/aquatic organisms to use, which makes it harder for them to survive
Hypoxia
A condition of water where there is a low amount of dissolved oxygen
Hypoxia can create a dead zone, where few/no organisms can even survive at all
Occurs when heat is added to an aquatic environment, making it warmer than it should optimally be
Generally speaking, the warmer the water is, the less dissolved oxygen it holds
Therefore, if heat pollution from industrial activities causes water to warm up too much, then it will become less optimal for wildlife
Factories and other buildings can heat up water by taking in cool water, using it to cool the factory steam, and then sending the warmer water back out into the environment
8.7 Persistent Organic Pollutants (POPs)
Persistent organic pollutants
Toxic chemicals that can’t easily break down in the environment
POPs can accumulate in organisms
When organisms that have POPs in their system are consumed by predators, those predators also take in those POPs and add them to their systems
Because POPs are fat soluble, they accumulate in an organism instead of leaving the organism’s body soon after entering
DDT (the insecticide) is an example of a POP
POPs can be carried throughout an ecosystem by wind and water
The process by which chemicals/substances, such as POPs, are absorbed by an organism and become concentrated in its cells
Biomagnification
The process by which predators/organisms higher on the food pyramid have higher concentrations of these accumulated chemicals than the prey did
Because apex predators need to consume large numbers of prey (that may have already consumed many prey organisms themselves), these apex predators are collecting harmful substances that each prey organism has accumulated
Humans can also experience negative effects from consuming organisms that have been contaminated
8.9 Solid Waste Disposal
Solid waste
Discarded material in the solid form (state of matter)
Electronic waste is a type of solid waste
Electronics companies may have to offer trade-in deals in order to take in used electronic devices that would otherwise have not been disposed of properly
Solid waste that is dumped into the ocean can interfere with aquatic organisms’ wellbeings, and it may accumulate in the ocean as pollution
Type of landfill that mas components designed to minimize harmful effects to the surrounding environment
Bottom liners, made of plastic/clay/etc, can prevent harmful substances from leaking into the ground/groundwater
Leachate and methane collection mechanics prevent leachate/methane from leaking into the environment
Storm water collection systems may prevent water from carrying contaminants to other areas
Incineration
A method used to burn/dispose of solid waste
Although this reduces the amount of physical space needed to hold solid waste, it also releases harmful air pollutants through the incineration process
8.10 Waste Reduction Methods
Recycling
A process where used products can be broken down, and their materials can be used in the creation of new items
This method can be expensive
Composting
Food scraps/other materials can break down, and the resulting product can be used as fertilizer
The nutrients from the food scraps are used to help grow new plants/etc
E-waste
Another word for electronic waste
Needs to be disposed of properly in order to prevent leachate/chemicals from polluting the area nearby
The dosage amount of a chemical at which 50% of a population will die from it
ED50 is the dosage of a non-lethal chemical at which 50% of the population will experience the non-lethal effect from the chemical (such as infertility/paralysis)
LD50 can be determined from experimentation on animals such as rodents instead of from experimenting on humans
Displays how increasingly large amounts of a toxin/chemical will take effect on a larger percentage of test subjects
The LD50 is identified as the dosage where 50% of the subjects die
Other points on the dose response curve show how a certain amount/dosage of a chemical (x-axis) kill __% of the samples (the percentage being found on the y-axis)
8.14 Pollution and Human Health
Synergism
Applies when two substances that each would have caused a certain amount of harm to an organism, when combined, cause an even greater amount of harm to that organism
Example: if substance 1 would have caused 2 units of harm, and substance 2 would have caused 3 units of harm, but exposure to both substance 1 and 2 cause 10 units of harm (instead of 5), then synergism is being displayed
Because humans are exposed to so many different pollutants, it can be hard to determine what caused each health response in a human
Dysentary
Humans can get dysentery if they interact with water that isn’t clean (such as water afflicted with sewage infections)
Additionally, exposure to asbestos can cause mesothelioma (a type of cancer)
Increasing tropospheric ozone levels can cause lung issues
Microorganisms that cause infectious diseases in humans/animals/etc
Infectious diseases can be transferred between organisms that act as hosts
Pathogens may spread through human populations and take advantage of hosts in order to reproduce/spread
Vectors
Living organisms, such as mosquitoes, that spread disease/pathogens from a host to another human/animal/etc
Because these vectors carry the pathogens from the old host to the new host, they help pathogens grow in number and spread across populations
Infectious diseases are harder to fight off in areas that are poorer, have less infrastructure, and have fewer resources because they don’t have the facilities they need to protect against and treat infections
Malaria and the West Nile virus, for example, are more common in less-developed areas
Cholera spreads more easily in less-developed places because it is contracted from infected/contaminated water
