unit 3 Flashcards
what are air pollutants
airborne substances released into the atmosphere deliberately or inadvertently from natural or anthropogenic sources that have the potential to harm health and the environment
types or airborne pollutants
gases, aerosols, particulates and/or biological matter
major concerns of air pollution
human health effects of smog, acidification of surface waters, crop and forest damage and damage to built structures
sources or air pollution
burning of fossil fuels, vehicle emissions, industrial processes, etc.
diseases linked to air pollution
respiratory diseases, stroke and heart disease
types of particulates (air pollution)
soot, vatious oxides, salts of metals and other inorganics, chemical mixtures of particles with organic substances absorbed into them
types of aerosols (air pollution)
sulphates and fine droplets of organic material
gases that are air pollutants
CH4, CO, CO2, SO2, NOx, VOCs
some chlorinated hydrocarbons
primary air pollutants
CO, NO, SO2, NH3, PMs (particulates) and VOCs (volatile organic compounds)
secondary pollutants
SO3, HNO3, H2SO4, H2O2, NH4+, O3, an PMs
Tropospheric Ozone
Thermal inversions
suppression of vertical air movement
atmospheric contaminants cannot rise out of the lower layer of air
what are the chronic effects of air pollution
remodeling of nasal epithelium
sensory irritation
bronchitis
lung infections, impaired clearance of bacteria, lung inflammation
impaired lung function, fibrosis
asthma, inflamed bronchial tube
carcinogenicity
cardiovascular toxicities
inflammatory conditions
Risk Management of air pollution
long range goals to decrease Ozone concentrations
emission controls for vehicles
control orders for certain industries
warnings (susceptible persons to avoid exposure)
PFAS
global pollutant
over 4700
human made chemicals
Ohio Train derailment
East Palestine, Ohio
overheating of a wheel bearing
50 0f 150 cars were derailed
20 of the derailed cars contained hazardous materials
EPA performed a controlled burn to prevent shrapnel but resulted in the release of VINYL CHLORIDE
air sampling
collecting an air sample over a period of time that is then sent to a laboratory for analysis to identify and quantify specific compounds
Air monitoring
uses electronic devices to provide real time readings of air born contaminants
Response to Ohio train derailment
installed Booms and underflow dams
vacuum trucks
EPA lead air quality testing
Water, soil and sediment sampling by EPA
soil removal for testing and disposal
home re-entry screenings
24/7 air monitoring at 23 stations throughout the community
opened a health assessment clinic
compounds of concern after Ohio train derailment
Vinyl Chloride
n-butyl acrylate
Ethylene glycol monobutyl ether
isobutylene
acrolein
mixtures
ended up in the creeks and ohio river and caused high number of wildlife deaths
Vinyl Chloride
used to make polyvinyl chloride (PVC) polymer
used to make a variety of plastic products (pipes, wire and cable coatings, and packaging materials
train was carring 490,000 L
Gas at room temp
liquid under high pressure
carcinogen (IRAC group 1)
acute toxicity 1000-8000 ppm (sweet odor)
pass out at 25000 ppm
can cause birth defects
what does Vinyl chloride break down into
hydrochloric acid, formaldehyde and carbon dioxide
routs of exposure for Vinyl chloride
breathing, eating, drinking and dermal
can dissolve in groundwater
side/after effects of the Ohio train derailment
psychological impacts (immediate stress of leaving the area, stress of unknown health consequences, loss of trust, house value declined, financial hardships)
class action lawsuit against Norfolk Southern Railway
improved transparency conveying uncertainties
long term health impact studies
continued environmental monitoring
PCPs
pharmaceuticals and personal care products
emerging contaminants
how do PCPs contaminante the environment
“down the drain”
when consumed a proportion is excreted into the sewage system
when absorbed into the body it is metabolized and then a portion of metabolites is excreted
sources of PCPs
individual use, Hospitals, domestic pets, agriculture, industry, landfill, sewage treatment, water treatment
effects of PPCPs in the environment
potential for long term impacts on ecosystem health
population-level effects on reproduction (can persists into future generations)
LOD
level of detection
what is the problem (PPCPs)
regulating every single one is problematic and unrealistic
as an emerging issue there are no regulatory guidelines in place
scientific information is not completely available
mixtures
not clear how to invoke the precautionary principle
current stance and precautions in Canada
no scientific evidence to suggest that the drinking water is not safe at this point
groups are monitoring the issue
PPCPs and the great lakes in 2014
over 165 individual pharmaceuticals and PCPs were found
detected because of new technology
more ppl are taking more and more drugs
concern for fish in great lakes exposed to PPCPs
intersex fish (immediate concern)
- males developing eggs in their testes putting survival of some species in jeopardy
PPCPs impact on humans
unknown
likely very little because of low levels
Hyderabad, India
- German scientists found that all of the specimens
collected from sampling sites in the direct environment of bulk drug
manufacturing facilities in Hyderabad and nearby villages, in India,
were contaminated with antimicrobials - also found 95% contained high levels of bacteria and fungi
resistant to antibiotic drugs
wastewater treatment plants
physically seerate oil and grease and dense particles from the water
then treat with bacteria to biodegrade contaminants
Goal: reduce oxygen demand, nitrogen and phosphorus nutrients, pathogens, contaminants and toxicants
waster water treatment limitations
never designed to remove molecule like pharmaceuticals
compounds that are biodegrade/metabolized during secondary treatment is random
where to start with PPCP regulations and drinking water
use minimum therapeutic dose as “acceptable level
solution for PPCP environmental contamination
reduce sources of pharmaceuticals to environment (restrict veterinary pharmaceuticals, control of reduced application of manure and sewage sludge, improve sludge treatment)
reduce levels in treated sewage before release
problem with reducing sources of PPCPs
not easy to reduce human consumption
hard to ensure proper disposal of medications
problems with reducing PPCP levels in treated sewage
requires a third step which is very expensive
PFAS
a large class of fluorinated organic compounds
anthropogenic
fluorinated substances that contain at least 1 full fluorinated methl or methylene carbon atom without a H/Cl/Br/I attom attached to it
over 47000 compounds (100 pharmaceuticals)
discovered in the early 1930s
hydrophobic tail and hydrophilic head
used for water/oil repellancy,chemical and thermal resistance , friction reduction and surfacant properties
highly used in commercial products since the 1950s
limited ecotoxicological data
Environmental impacts of PFAS
very long residence time
found virtually in all environmental matrices (groundwater, rainwater, soil, ocean, etc.)
shorter PFAS are smaller and more bioavailable to organisms
Canadian PFAS drinking water guidelines
do to uncertainty of risk and limited data the precautionary principle has been invoked
objective conc for drinking water is based on a sum of PFAS detected ( there are 25)
sum of their conc shall not exceed 30 ng/L
regulatory guidelines only account for 1% of PFAS chemicals
regulations are low due to the relatively recent emergence of PFAS concern and the inability of conventional toxicity tests to asses them.
how to predict substance risk
literature review
toxicity tests conducted in a laboratory and in the field
most methods to determin lethality of contaminants arise from mammalian toxicology from the early 1900’s
toxicant effects
lethal and sub lethal
contaminant lethality
acute: death followed after 96 hours
Chronic: death followed by prolonged exp
measuring developmental effects
conventional assays often use highly understood model organisms
what is behavioral toxicology
the study of abnormal behaviors produced by toxicant exposure
short comings of Behavioral toxicology
- some behaviors are hard to score
- high variability in some behaviors
- hard to extrapolate from to wild settings
disadvantages of conventional toxicity tests
time consuming and costly
requires large numbers of test organisms
Novel approach methods
any technology, methodology, approach or combination that informs chemical hazard and risk assessment method
aid in the removal, reduction and or refinement of animal toxicity testing
allows for high throughput assessment of chemicals
replacement
methods which avoid or replace the use of animals
in vitro instead of in vivo
approaches
- laboratory grown cell lines
- toxicogenomic
- computer simulations
refinement
methods which minimize suffering and improve animals welfare
reduction
methods which minimize the number of animals used per exp
Ecotoxicogenomics
the study of gene and protein expression using omics technology to understand the effects of environmental contaminants
benefits of ecotoxicogenomics
enhances toxicity data (toxicity mechanisms)
- shorter duration for toxicity testing ( high throughput)
(effects at the mRNA level occur much earlier than other conventional endpoints currently used)
(EC50 values for gene expression rates are much lower than reproductive and lethal endpoints, approx 11 times)
reduces suffering of organisms (shorter test durations)
compatible with in vitro tests/systems
can help identify a contaminants mode of toxicity
identify the presence of a contaminant
types of Omics technology and what they measure
transcriptomic: the study of gene expression levels
proteomics: study of protein expression levels
Metabolomics: study of metabolites within organisms
types of gene expression profiles
RT-qPCR, Microarray and RNA sequencing
what are cell lines
population of cells derived from a single tissue source that can be repeatedly grown and maintained in a laboratory culture for an extended period
Lessons learned from ecotoxicogenomics for PFAS
have a conserved toxicity pathway across species, tissues and even molecules
exposure can lead to:
endocrine disruption
- decreased estrogen receptors
- disrupts thyroid hormone transport
- increase lipid metabolism and transport, as well as gonadotropin and FSH pathways
decrease in immune response
- inhibits blood clotting and tissue repair
- decrease drug metabolism
oxidative stress
candidate biomarkers
expressed following exposure to a specific contaminant
can be identified using ecotoxicogenomics
Computational Model ADMET
absorption, distribution, metabolism, excretion and toxicity
products of pulp and paper industry in Canada
market pulp, boxboard, cardboard , paper (many types)
trends in Pulp and paper production
continued growth globally
- primarily driven by packaging
- China and US are top producers
more new mills in Asia and Latin America
Environmental impacts of pulp and paper production
Habitat destruction
- deforestation
- physical changes to lakes and rivers (Dams, log floating causes physical damage to benthic habitats, water consumption for processing)
soil pollution from disposal of solid wastes (wood products and toxic chemicals)
Air pollution (CO2 emissions, reduced CO2 fixation, toxic emissions)
water pollution
- O2 consuming substances (bacteria that breaks down wood
- toxic chemicals (Hg, chlorinated compounds, wood extractives)
- persistent bio accumulative compounds
Hydroelectric dams
physical impact of paper mills
change flow and temp regimes of water
block fish migrations
upstream sediment accumulation
log driving
physical impact of paper mills
scour river bottoms
create fibre deposits
release toxic wood extractives
stopped in 1991
chemical impacts of paper mills
components of wood
- Fibre (product): Cellulose and Hemicellulose
- sugars (By-product)
- Lignin (by product)
- Extractive (By-Product): tall oil, turpentine, resin acids, and phytosterols
Lignin
glue
is a random polymer of phenolic compounds
lignin degradation by pulping and bleaching creates a wide array of toxic phenolics and polyphenolics
Thermo-mechanical (TMP)
pulping process
> 95% yield
brown
boxboard, newsprint, paper bags
Doesn’t last very long
Chemi-Mechanical (CTMP)
pulping process
85-95% yield
light brown
Newsprint, specialty papers
Semi chemical
pulping process
60-80% yield
Beige - Brown
Newsprint, bags
Chemical - Kraft & Sulfite
pulping process
40-55%
lightest brown
newsprint, fine papers
most common in Canada
- pulping chemicals (creates volatiles, energy and By products)
- Cl bleach
- water wash
- Cl bleach
- water wash
waste water receives two treatments ( both produce volatiles and particulates (BIO solids)
Bio solids undergo a soil treatment and then get released back into the environment with the remaining waste water
Effluent chemicals Affecting Aquatic Environments
Oxygen consuming wastes
- BOD (biological O2 demanding)
- COD (chemical O2 demanding
- Wood Fiber
Chemical spills
- alkaline pulping solution: acid bleachery wastes
Persistent, bioaccumulative and toxic (PBT) compounds
- Hg
- Resin and fatty acids
- Chlorinated phenols
- Chlorinated dioxins and furans
Mercury Tragedy
Dryden pulp and paper
- discharged inorganic Hg
caused biomagnification in fish
caused brain damage in aboriginal consumers of fish
moving the reserve to avoid Hg contamination created enormous economic and social disruption
old landfills and the pulp mill continue to leach Hg
Pulp Bleaching processes
chlorine hypochlorous acid
alternatives
- chlorine dioxide hypochlorous acid
- peroxide
- ozone
chlorine hypochlorous acid
cleaching process
efficient
removes colour
not much fibre breakage
generates chlorinated compounds
abandons (crisis of chlorinated dioxins in fish & shellfish)
peroxide
alternative to chlorine hypochlorous acid
H2O2
no chlorinated contaminants
less efficient
used alone or in combination with ClO2
Chlorine dioxide, hypochlorous acid
ClO2, HClO
alternative to Chlorine hypochlorous acid
main bleaching agent in Canada
most efficient
minimal chlorinated contaminants
worker safety issues
Ozone
No chlorinated contaminants
less effiecient
alternative to chlorine hypochlorous acid
O3
used alone or in combination with CIO2
paper effluent effects
evidence of reproductive impacts
- serum sex hormones of males
- sexual maturation
wood extractive mimic cholesterol, block cellular uptake of cholesterol and impar sexual maturation
treatment reduces O2 demand and acute toxicity
pulp mill impacts post 1980’s
smaller footprint, greater reliance on recycled fiber, lower discharge of BOD, COD and toxic chemicals, virtual elimination of dioxins and furans
fish kills are rare, less sublethal toxicity
New issue
- eutrophication due to nutrient enrichment from waste treatment
solutions to current problems with pulp and paper mills
instead of end of pipe solutions, improve the pulping and bleaching processes
- recover carbon from pulping liquors and waste fibre and recycle as green energy
- replace Cl2 for bleaching with O2 delignification
- Re-use and recycle was waters
- reduce mill upsets with computer process controls
- identify toxic waste stream and focus controls on specific source before they are diluted and difficult to treat
ultimate goal of Pulp paper effluent treatment
zero discharge, closed loop mill
current challenges with pulp mill effluent treatment
removing chemicals from effluents without increasing toxicity, creating solid waste and releasing air pollutants
what are brownfields
Abandoned, idle or underutilized commercial or industrial properties where activities have caused known or suspected contamination, but where there is an active potential for redevelopment
positive attributes of brownfields
location is in urban areas
sites preferred over greenfield development
arteries - roads, rail, water
municipal services in place
possible heritage interest
Negative attributes of brownfields
depress local property values
catalyst for poor property standards
loss of community pride
human health and environmental risk
- immediate exp to contaminants in soil
- risk for substances moving from the soil to ground or surface water
loss of tax revenues
cost to clean up and redevelop
brownfield remediation efforts
expensive
phytoremediation
educational depot
indigenous concerns
what is ecotoxicology
the study of chemical effects in ecosystems and natural communities
seek to understand relationships among the structures of chemicals, their environment behaviour, distribution and effects on species on interest
what are micro plastics
<0.5mm
physical and chemical toxicants
enter the environment through multiple pathways
easily ingestible by smaller organisms
methods in ecotoxicology
mesocosms ( can also look at other components of the mesocosms environment, such as the zooplankton, biofilm and sediment to better understand realistic effects
sample lakes
sampling specimens
systemic evidence maps
systemic evidence review
What is 6PPD
class of anthropogenic antioxidants
widely applied in the rubber industry to protect materials from flex cracking, heat degradation and ozone cracking
what was responsible for the mass die offs of co ho salmon
a transformation product of 6PPD
toxic component of urban storm runoff
systemic evidence maps
gather the body of evidence (search and screen for all relevant articles)
collate information to facilitate cross-discipline connections
identify research trends and knowledge gaps
systemic evidence review
critically appraise and synthesize evidence to asses the strength and reliability of studies
transcriptomic analyses
provide a snapshot of global molecular changes that reflect cellular responses to stressors and progression toward disease
transcriptomic points of departure
identify the chemical conc below which a concentrated change in gene expression is not expected in a biological system
holistic lake health
key indicators: function, connectivity and resilience
- understanding species interactions
cultural assessment models
use multiple tools that complement each other
biodiversity
- moving beyond water quality to describe ecosystem health
susceptibility and diagnostic assessment of lake health
early warnings of change
- utilizing local knowledge to inform our approach
- develop tools to identify decline in lake health
in-lake nutrients
- understand how nutrients in lakes impact their health
- existing data can help predict at risk lakes
extreme climate impacts
- using recent and historical data to understand impacts
- preparing for future change scenarios
Lake restoration framework
determining the enabling social drivers
understanding the barriers to restoration
engaging action
inspiring the next generation
informing good lake management
community priorities to guide restoration
getting ahead of climate changes
sharing the knowledge
why should we turn to renewable energy
energy security
environment
employment
high energy prices
energy security
significant increases in global and Canadian energy demand; political instability in key oil producing regions
environment and the need for renewable energy
need a suite of renewable and sustainable energy technologies that can reduce GHG emissions over fossil energy (responsible for 2/3 of climate change)
renewable energy and employment
requires less ppl in energy generation but there are more jobs in the tech
renewable energy and high energy prices
moving towards renewability can bring back stability
why waste to energy
removes/greatly reduces the need for landfill sites, avoiding potential problems down the roas
reduces the need for waste treatment
reduces our footprint on natural resources- by utilizing waste , we avoid using renewable or fossil resources
power back = power pays for power
reduces costs - companies may avoid paying for feed stocks or disposal costs
criteria for success in turning waste to energy
technically sound approach
environmentally sustainable
economical
safe and reliable operations
small footprint and attractive design
- must be acceptable to communities where power is needed, to reduce transmission & distribution losses
simple and quick permitting process
sources of oil earning ( the “refinery” approach)
50% comes from transport
20% comes from asphalt (if we remove oil we will need to find a new way to make roads)
important principles for the success of waste to energy
most businesses need a value added output
tipping fees are almost always essential - companies must be paid to take waste and also make money from products in order to ultimately be profitable
many businesses generate energy aas a coproduct to their major money maker
up and coming waste-energy techniques
plasma refining systems (plasma brakes waste down into its most basic element), but you need energy to make plasma
- Plasco conversion technologies
- over promised
- only worked if companies paid to dispose of their waste
anaerobic biogas production and material recovery
- biogas can be turned into energy and used for aquaculture, electricity generation and heat generation
- get methane (combusts fast, produces a lot of energy but is very poisonous)
- EnEco
use of sorted municipal solid waste as feed to create electricity and liquid fuels
- likely over engineered
- Enerkem
gasification of wood waste to generate heat and syngas
- low tech approach
- Nexterra
what about plastics (renewable energy)
most problematic
may also be a good source of energy
most of them are petroleum based
disposal has been difficult (hard to know which plastic is what type, difficult to sort)
critical concerns include the potential for increased emissions aand cost of recovery
problems with combusting plastics
without proper controls it can result in increased CO2 but also the production of dioxins furans, heavy metals and polychlorinated biphenyls
need temps above 800 degrees C for proper and safe combustion
many of the compounds are persistent organic pollutants that bioaccumulate within the food chain and can be extremely harmful to health
design principles in order to achieve full combustion
temps must be very high and/or residence times must be very long in order to ensure that all material is reduced to constituent gases and trace elements
trace elements, including heavy metals must be recovered and disposed of separately (separating slag)
proper monitoring and reporting is required to ensure that plants are operated with a minimal impact on the surrounding environment
municipal reluctance on waste to energy
Municipalities are not eager to sign up for long term contract
communities are highly concerned about the potential pollutants involved in combustion of waste streams
many new technologies and players (herd to know which one to go with/is the best)
very difficult to validate performance, particularly for small communities
- better national regulation is likely needed to promote these options*
why is waste to energy gaining popularity
increased cost of fossil energy, increased emissions and concerns over environmental impacts including climate change
