1
Q
A
2
Q
What are pesticides?
A
any physical chemical or biological agent that will kill an undesirable plant or animal plant
- goal is to selectively kill pest with little to no toxicity to non target species
- biological processes are highly conserved across species which makes it difficult to target a single organism with no effects on other ones
3
Q
How are human exposed to pesticides?
A
- detectible in 92% of children, 82% of adults
- found in 72% of fruits and veg
- found in homes, indoor air, over 90% of stream samples
4
Q
5 major types of insecticides and their basic action
A
Organochlorine compounds - disrupt ion channel functions at nerve cells
Pyrethoids - same
Organophosphates - inhibits acetylcholine esterase
Carbamates - same
Neonicotinoids - nAcH receptor agonist
5
Q
Are organic foods pesticide free?
A
In theory yes, but trace levels of pesticide are found on 70% of organic foods
6
Q
4 types of organochlorine compounds?
A
- DDT
- hexachlorocyclohexane
- cyclodienes
- polychloroterpenes
7
Q
Chemistry and kinetics of organochlorine insecticides?
A
- synthetic compounds
- some amount of Cl substitution
- highly lipophilic, rapidly absorbed and enters CNS
- resistant to breakdown - persistent chemical
- most have high biomagnification potential
8
Q
Chemistry and kinetics of pyrethoid insecticides
A
- synthetic analogs of naturally produced pyrethrins
- low water solubility
- natural products and undergo rapid biodegredation and metabolism
- low mammalian toxicity but toxic to fish and inverts even at low doses
- some require other chemical synergists to icnrease potency
9
Q
Two pyrethroid synergists?
A
Piperonyl butoxide and sesamex
- non toxic themselves
inhibits detoxifying enxymes so they cant break down pyrethroids (CYP)
10
Q
Classes of pyrethoid insecticides
A
Pyrethrum - Pyrethrin 1
- 4 different plant compounds
- unstable in sunlight and requires syynergist
!st and 2nd generation - Allethrin
- improved stability and efficacy
- still requires synergist
- household uses
3rd and 4th generation - Permethrin
- photostable, no synergist required
- agricultural uses
11
Q
Chronic effecs of organochlorine insecticides - specificially DDE
A
- DDT/DDE banned in the 90s but DDE persists in environment for up to 30 years so chronic exposure is not uncommon
- endocrine disruption
- disrupt reproductive functions
- feminization
- interferes with calcium metabolism during egg production in birds causing thin eggshells and embryonic mortality
- some are tetragenic (can be passed from mother to fetus) or carcinogenic (DDT)
12
Q
4 common organophosphates
A
orthophosphoric acid
methyl parathion
diazinon
chlorpyrifos
13
Q
4 common carbamates
A
carbamic acid
carabryl
primicarb
carbofuran
14
Q
Chemistry and kinetics of organophosphates and carbamate insecticides
A
- Organophosphates are derivaties of orthophosphoric acid
- moderately water soluble (not very halogenated in insecticides)
- carbamates are synthetic derivatives of carbamic acid, usually more polar and water soluble than OP
- both compounds rapidly degrade in the enviornment - not persistent
15
Q
How do organophospates and carbamates impact the body?
A
they both act as acetylcholine mimics and bind to the cholinesterase enzyme
- organophosphates bind irreversibly and carbamates bind reversibly
-acetylcholinesterase is responsible for breaking down acetylcholine - meaning it will build up in the body causing twitching, overstimulation of the heart, paralysis among others
16
Q
Organophosphate acute and chronic toxicity
A
Acute - number one responsible for acute insecticide toxicities in humans in Canada
Chronic - lethargy, amnesia, depression, neurological disorders dimentia, autism etc)
17
Q
Case study of carbofuran
A
- was used extensively as an insecticide
- estimated to ill 19 million birds / year
- a single grain was lethal to many species
18
Q
Name 4 neonics
A
nicotine, imidacloprid, clothianidin, thiamethoxam
19
Q
How do neonics work?
A
they act as nicotinic acetylcholine receptor agonists, meaning they wll bind to the nicotinic acetylcholine receptors
- effectively causes permanent binding to receptors which causes permanent overstimulation and destruction
20
Q
What is the current regulation of neonicotinoid usage?
A
in 2018 EU banned 3 neonics
- were to be phased out by health canadas pest management regulatory agency (PMRA)
- in 2018 PMRA recommended that the 3 neonics should be phased out over 3-5 years
- in 2021 health canada changed its decision and deemed them acceptible with mitigation
21
Q
Health consequences of air pollution in Canada?
A
15000 premature deaths / year
- significant economic costs due to hospitalization
22
Q
4 major types of air pollutants
A
Gaseous
- inorganic SO2, NOx
- VOCs
Particulates
- particles 0.01-100um
- other gases will adsorb to particles
Droplets
- small liquid droplets will remain suspended in air
- other gases may dissolve in droplets
Smog
- combination of smoke and fog
- gases and particulates
23
Q
What are primary and secondary air pollutants?
A
Primary - harmful chemicals that enter directly into the atmosphere
Secondary - harmful chemicals that result from interactions of primary pollutants or with other compounds in the atmosphere
24
Q
What is sulfur dioxide (SO2)
A
Primary air pollutant
- anthropogenic source - combuestion of fossil fuels / smelting ores
Toxicity - plants - affects photosynthesis, transpiration, respiration
humans - chronic lung diseases
- cause of smog
25
What is NO and NO2?
Primary air pollutant
anthropogenic source - combustion of fossil fuels
Toxic effects - plants - inhibition of photosynthesis and lipid biosynthesis
humans - irritation of lungs, lowered hemoglobin, lower immune function
26
What is CO
Pirmary air pollutant
anthropogenic source - combustion of carbon materials including hydrocarbons
- can remain in atmo for up to a month
- primary source in canada is transportation
toxic effects
- hypoxia
- tissue damage
- immune and cardio impairment
-reduced birth weight
27
What are VOCs
Volatile Organic Carbons
- Primary air pollutant
- Anthropogenic sources - carbon containing gases ad vapours such as gasoline fumes and solvents
- Toxic effects to long term exposrure - carcinogenicity (PAHs) and neurotoxicity
28
29
What are the three kinds of particulate matters?
Types of primary air pollutants
Coarse particulates - PM10s
- pollen, seasalt, man made producits
- metal oxides of silicon and aluminium
- precipitate quickly
Fine particulates - PM2.5
- carbon materials, sulfates, nitrates
- trace metal compounds
- small partiles are charged but may bind lipophilic compounds
- main source is dust for above with ag coming in second
Ultrafine particulates - PM0.1
- same as PM2.5 but smaller
- easily taken up by systems due to size
30
is indoor or outdoor air pollution more common?
indoor air pollution is greater
31
Why is indoor PM2.5 air pollution much higher than outdoor pollution and much higher in developing countries?
- main reason is burning wood, charcoal inside to generate fire for cooking on / heating the home
- full ventilation / air purifying systems are less common
32
Where will each size of PM end up?
PM10 - trachea / primary bronchi
PM2.5 - tertiary bronchi
PM0.1 - alvolar sacs / alveoli - most dangerous, only a single cell layer where gas exchange occurs
33
mode of toxic action ofr fine particulate matter
increases WBC which wincreases chronic inflammation which increases reactive oxygen species which causes oxidative stress and damage in cells - starts inflammation bc immune response sees them as pathogens
34
Toxic effects of Particulate matter exposure in humans
- fine particles retained in lungs
- lung and systemic inflammation
- chronic bronchitis, COPD,
- induce acute cardiovascular events
35
Two important secondary pollutants
Ground level ozone - O3
Acid rain - H2SO4 and HNO3
36
What is ozone O3
- normal component of the stratosphere
- ozone reacts with CFC and is broken down - how the ozone hole formed
- ground level ozone is toxic
- highly oxidiziing and will do extensive damage to vital cellular proteins and enxymes / DNA
37
What makes up the majority of photochemical smog?
90% ground level ozone
38
What primary air pollutants are the eventual source of ground level ozone?
- Nitric oxide
-carbon dioxide
- hydrocarbons
- sunlight
- NO + O will go back and forth with NO2 w / sunlight
- VOC + NO is high affinity
- will form PANs + aldehydes
- leaves singlet O which will bind with O2 to form O3
39
What geographical phenomeonon can prolong photochemical smog?
Temperature inversion where it goes cool warm cool intead of warm cool cooler - can happen in large cities
- will increase duration of smog
40
Two primary air pollutants for acid rain?
SO2 and NOx
41
What three acids when reacted with water vapor are wet deposited
Sulfuric acid - H2SO4
nitric acid - HNO3
Nitrous acid HNO2
42
Major impact of acid rain?
Water body acidification - can cause lethality depending on buffer capacaity
- Deforestation - acid rain will damage leaves and bark
- increases solubility of toxic metals
- damages soil fungi
43
What makes up AQHI?
ground level ozone, PM2.5/PM10 NO2
AQI in USA - scale of 0-500 instead of 0-10
44
What is unique about radionuclides as environmental pollutants?
They are hazardous due to their physical properties not chemical ones (like most pollutants)
45
Two kinds of radiation?
ionizing -- high energy can ionize biological molecules - UV, Xrays, Gamma rays
nonionizing - lower energy, cannot ionize biological molecules - radiowave,s microwaves, infrared, visible light
46
Two sources of radioactivity?
Natural
- cosmic rays
- natural radioisotopes - uranium/ radium
Anthropogenic
- nuclear reactors
- waste from uranium mining / milling
- production of medical radioisotopes
- xrays
47
3 types of radioactivity waste
Low radioactivity, high volume waste - majority of waste - contains material with limited amounts of long lived activity, requires containment for a few hundred years
Intermediate radioactivity low volume waste - typically exhibits levels of penetrating radiation adn contains significant quantities of long lived radionuclides
High radioactivity low volume waste - includes used nuclear fuel and other wastes that have been declared as waste, contains significant quantities of long lived radionuclides
48
5 types of ionizing radiations (2 classes)
Particle radiation
- alpha particles
- beta particles
- neutron particles (non natural only happens by splitting in reactors)
Electromagnetic radiation
- gamma rays
- x rays
49
Alpha particles
- relatively large mass
- consists of two protons and two neutron
- do not travel far in air (1inch)
- minimal external hazard
- significant hazard and cellular damage when internalized
50
Beta particles
- electrons / positrons emitted during decay
- half the charge of alpha particles
- travel further than alpha
- less dangerous internally but can still cause regional injury
51
Gamma rays
- EM wave no charge
- ionize matter bby interaction with orbital electrons
- highly penetrating
- can produce whole body exposure
- equally dangerous with external or internal exposure
- overall less hazardous than A and B
52
Nature and intensity of decay / radiation
EM photons (Gamma and X)
- lowest energy
-highly penetrating - can be blocked by lead or concrete
B particles
- higher energy
- less penetrating, can be stopped by wood or skin
A particles
- highest energy / worst
- stopped by a sheet of paper or outer skin surfaces
53
Units of radiation
Bq - becquerel - number of atoms disintegrating / second
Ci - Curie - number of disintigrations / seconds in 1g of radium
Gy - Gray - amount of radiation causing 1kg of tissue to absorb 1 joule of energy
Sv - sievert - takes into account the damaging potential of the absorbed energy - safe annual dose form humans is 1mSv
54
How to convert the dose of radiation in Gy to effect in Sv
Dose in Gy x QF = Sv
QF = 1 for gamma, x and beta particles
QF = 20 for alpha particles / neutrons
55
what taxonomic group is the most and least sensitive to radiation
mammals are the most sensitive and viruses are the least
56
Sensitivity of tissues and organs to radiation
Most sensitive
- blood forming organs
- reproductive organs
- skin
- bone and teeth
- muscle
- nervous system
least sensitive
57
Indirect and direct effects of radionuclides / toxic action
Indirect effects
- ionizing radiation
- will split water into H+ and hydroxy radical (+1e-) - significant oxidative stress on the body
Direct effects
- ionizing radiation can directly encounter macromolecules like proteins lipids and DNA and ionize them directly causing them to misfold or be unable to replicate
58
Where will iondine 131 exposure accumulate in
analog to iodine normal, will accumulate in thyroid gland which can lead to thyroid cancer
59
Where will Cs 137 end up?
analog to K, can accumulate in all organs
60
Where will Sr 90 end up?
analog to calcium, will accumulate in bones
61
62
YOU MISSED THE LECTURE AFTER RADIONUCLIDES
ok ok chill shawty
63
What are nutrients in the aquatic environment?
chemical substances that provide nourishment to promote growth, 2 points of uptake
- microorganisms
- aquatic plants
- includes macro and micronutrients
64
What is usually the limiting nutrient for eutrophication accoring to the full lake fetilization case studies?
P
65
How do we classify the trophic status of a lake ecosystem?
- strong correlation between algal growth and phosphorus
- can classify as eutophic if P is greater than 30 ug/L
66
Why are N and P limiting nutrients in freshwater?
demand is greater than natural environmental supply by very large amounts
67
P chemistry in water
- less mobile than N
- combines readily with cations and clay
- forms insoluble products and precipitates under oxic conditions
- PO43- is considered the bioavailable form of P but occurs in super low concentrations in the environment
68
N chemistry in water
- present in high concentrations similar to O2 as N2 in water
- needed for important biomolecules
- however N2 is only bioavailable for specific nitrogen fixing prokaryotes
- can exist as ammonium (for bacteria) or nitrate / nitirte
-ammonium is reduced form of N found in neutral / acidic waters
69
Two kinds of unnatural sources for nutrient pollution
Point source - sewage and industrial discharge
- urban storm water
Nonopoint source - ag runoff
- atmospheric deposistion
70
How do lakes end up with excess P causing eutrophication?
P is applied to ag landscapes as a fetilizer and can be carried into surface waters
- PO43- will bing to soil and accumulalte - saturating the landscape with P
- as rain comes and erodes the soils, P leaches into water bodies
71
Definition and impacts of cultural eutrophication
enrichment of natural waters with nutrients as a result of human activities
- loss of habitat /biodiversity
- killing fish
- loss of recreational value
- toxins
72
Oxygen availability in water colum
epilimnion - warm surface water high O2
metalimnion - middle region - rapidly declines in O2
hypolimnion - anoxic, drops to 0 O2, helped by microbes to create anoxic conditions
low nutrient lakes can have O2 highly available at depth in cold water, where as eutrophic lakes have low O2 in cold waters - due to algae using all the oxygen / increased BOD when nutrients are available
- lack of oxygen can kill fish at depth
73
What are cyanotoxins?
- cyanobacteria can bloom and release neurotoxins into freshwater under warm and calm conditions with high nutrients
74
Unlike freshwater systems, marine systems tend to be ____ limited?
N limited
- undergo eutrophication from river and estuary nutrient inputs
- made worse by sewage dump into costal waters
75
What are red tides?
red marine surface waters
- caused by a bloom of dinoflagellates
- color is caused by an accumulation of carotenoid pigment s
- generally restricted to autotrophic genera
- need calm warm water with low salininty and high nutrient conditions
- may occur after heavy rainstorms that wash nitrogen off farmland into coastal waters
76
What is saxitoxin?
neurotoxin released from dinoflagellates which accumulate / create red tides
- called paralytic shellfish poisoning
- saxitoxin gets into bivalves and then humans when eaten (or eating crustaceans that eat bivalves
- causes respiratory difficulty and paralysis
77
What is amnesic shellfish poisoning?
Pseudo-nitzschia can produce the neurotoxin domoic acid
- when shellfish consume the diatom they concentrate the toxin in their tissues but remain unaffected
- when humans consume the shellfis they get memory loss, vomiting and death
78
Define complex effluents
Water mixed with waste matter - liquid waste discharge
- contain complex mixtures of compounds both natural and man made
- exert complex effects on organisms - often site specific
79
Sources of complex effluents?
Domestic - municipal wastewater (sewage)
Industry - metal mines
- pulp and paper mills
- textile mills
- processing plants
- meat and poultry products plants
- petroleum refineries
80
What is municipal wastewater and why is it relevant?
Liquid wastes from sewer systems and municipal wastewater treatment plants (MWTPs)
- MWTPs discharge 5.7 billion m3 annually in Canada
- contains organic wastes, suspended solids, nutrients, pathogens, chemicals
81
Impacts of municipal wastewater on aquatic environments?
- increased nutrient levels in waste can cause algal blooms or eutrophication
- algal blooms result in lower dissolved oxygen in water, which can kill aquatic life
- destruction of habitats
- chemical contaminants - estimated 60 000 man made chemicals in use, most enter the aquatic environment (pharmacuticals are a major issue)
82
Impacts of municipal wastewater on human health?
- recreational swimming in contaminated areas can lead to bacterial contamination
- fishing - fish can accumulate toxicants which can be passed on to humans
- contaminated drinking water, with bacteria, metal, nitrate, organics, drugs
83
What are the two sources for municipal wastewater discharge
- Sanitary sewage - generated rom homes, institutions, industry
- Stormwater - generated from rain or melting snow that drains off rooftops, lawns, roads, other surfaces
- usually treated together
84
How are wastewater services organized in Canada?
- most systems are owned by the municipality
- all levels of government share responsibility for managing the collection treatment and release of wastewater effluent
- Federal government is responsible for managing risks unfer CEPA
85
4 steps of water purification / treatment
Preliminary - screening
Primary - sedimentation
Secondary - biologcial loads
Tertiary - removal of bacteria, suspended solids, specific toxic compounds or nutrients
86
What is BOD?
biological oxygen demand - amount of oxygen needed to break down organics - higher BOD = poorer quality of effluent
87
Why do the prarie provinces have better wastewater treament?
Need to keep water clean since freshwater is a limited resource
88
What is WET?
Whole effluent toxicity - test run by provincial government to approve municipal wastewater treatment effluents
- toxicity tests of undiluted effluent required to permit release of effluents that have potential to cause deleterious effects on recieving aquatic environment
- pass = approved to release into environment
- fail = toxicity reduction evaluation is needed
89
Some Canadian wastewater systems effluent regulations (WSER)
- Average BOD <25mg/L
- Average concentration of suspended solids <26mg/L
- Average concentration of total residual chlorine <0.02mg/L
- Maximum concentration of unionized ammonia <1.25mg/L
- Effluent must not be acutely lethal based on test methods perscrbed in regulations
90
What is a TRE?
Toxicity reduction evaluation
- identify causative agent
- isolate source of toxicity
- evaluate effectiveness of removal
- confirm reducation in effluent toxicity
91
Why does every metal mining plant have a wastewater treatment plant?
To treat wastewater from the mine, waste rock and tailings
Reduce
- toxic metals / chemicals
- control pH of effluents
- total suspended solids
- dissolved organic carbon
Metals and low pH is bad bc metals are more soluble / bioavailable in acidic water leading to increased toxicity
92
History of metal mining in Canada
Began in 1800s
- 1960s - contaminaiton became a concern, evidence of heavy metals in surrounding lakes and rivers
- 1970s - substantial effort by industry to control metal discharges
- 1990s - metal mining industry regulated under the EEM environmental effects moitoring program
93
Regulations for MME
- Concentration of the deleterious substances (metals) in the effluent does not exceed the authorized limits (weekly)
- pH of effluent is beteen 6 -9.5 (weekly)
- undiluted treated effluent is not acutely lethal (<50% mortality of rainbow trout over 96 hrs) (monthly)
EEM assessment every 3 years
94
What does the EEM monitor?
effects on communities in the envionment that recieves mining effluent
95
Objectives for EEM in aquatic environment
- FIsh are used as endpoints
- Need to determine bioaccumulation level
- Fish habitat and benthic invertebrates - diversity and abundance
96
Compare and contrast WET and EEM regulations
While WET tests for acutely lethal concentrations of chemicals, there is no requirement for testing ecological impacts / environmental effects of the effluent even if levels are below the standard
EEM creates a historical record of environmental health of the receiving system, continues with weekly, monthly and total evaluations every 3 years
97
What are PPCPs?
pharmaceuticals and personal care products in the environment
98
Are PCPPs persistent pollutants?
-usually classified as non persistent pollutants
- degrade rapidly in the environment
- while not chemically persistent, usually present in high concentrations due to high loading / continuous renewal in the environment - pseudopersistant
- show low bioaccumulation in biota
- do not biomagnify through food chains
- generally not acutely toxic
99
Are PCPPs acutely toxic?
- generally do not biomagnify and are not acutely toxic
- however may have biological effects even at low doeses
100
What kind of personal care products end up in the environment?
fragrences (synthetic musks)
suntan lotion
skin cream
insect repellent (DEET)
antibacterial agents (triclosan)
101
What are synthetic musks?
Emulate the odor but not structure of expensive natural products
- polycyclic or nitro compounds
- synthetic musks are relatively lipophilic and bioaccumulate in fish downstream of urban areas
102
Which synthetic musks bioaccumulate / are they toxic?
polycyclic musks bioaccumulate in fish (AHTN, HHCB, ATII)
unknown toxic effects
103
Types of drugs that end up in the environment?
synthetic hormones
analgesics and antiinflammatories (NSAIDS)
antibiotics
antacids and ulcer drugs
blood lipid regulators
cardiac drugs
antidepressants
antiepileptics
cancer / chemotherapy drugs
104
What was found about antipsychotic drugs in sasktchewan rivers?
concentrations of antipsychotics were found in ng/L concentrations
- generally higher in downstream sites
- amitriptyline, an antidepressnt, was the most abundant drug
- concentrations were below toxicity thresholds at SDS but higher at WDS at all seasons ( above toxic thresholds in regina)
105
What is the asian vuture crisis?
- catastrophic decline in vultures in last 25 years
- declines leading to ecosystem disruption with human health implications
- death from build up of uric acid (gout) which does not occur in humans
- decline attributed to diclofenas (a NSAID) which is used to treat cattle in asia
106
what are environmental estrogens?
- pharmaceuticals (oral contraceptives, hormone replacement therapies)
- natural (estradiol, estrone, estriol)
- detergents (nonionic surfactants, mainly alkylphenol polyethoxylates)
107
How did addition of estrogen to estrogen lake affect the community?
-ethinylestradiol (oral contraceptive) were added 3x weekly for 5 months
- decreased algal diversity
- decreased fecundidty and abundance of zooplankton
- intersex male flathead minnows and lake trout
- reproductive failure in minnows
- decreased hatching success of green frogs
- intersex in tadpoles
108
What is the biggest potential human health impact of continuous exposure to PCPPs in water and food?
development of antibiotic resistant microorganisms in the environment
109
What is the risk for human consumption of PPCPs through vegetables / plants
PCPPS bioaccumulate in vegetables to varying degrees but are genrally low concentration and at no risk to humans
110
Are there any local pollutants in the arctic?
no, no local sources, all pollutants are brought from further south
111
What is AMAP?
arctic monitoring and assessment program - est 1991 for monitoring arctic pollution
- provides reliable and suffieicent information on the status of the arctic
112
What is the NCP?
the Northern Contaminants Program - est 1991 in response to concerns about human exposure to elevated levels of contaminants in wildlife species that were essenetial to traditional diets of arctic indigenous peoples, ended up finding high levels
113
What are the types of contaminants in the arctic?
Organics - POPs
Metals - Hg, Cd, Pb
Radionuclides from old mining operations (?)
POPs are major issue
114
What are legacy POPs?
POPs that have been banned, but are still found in the arctic
- PCBs
- PCDFs
- DDT
115
What is notable in Arctic Char in char lake?
most POPs esp DDT and PCP concentrations have stayed consistent since the 90s, at high levels
116
What degree of chlorination POPs are found in the highest concentration in arctic char?
Moderate degrees of chlorination
- Penta or Hexa
117
Where are POPs found in the arctic?
everywhere, especially pronounced in winter
118
What are the physical chemical properties of legacy POPs that re found in higher percentages in the arctic?
have characteristic chemical signature
- moderate degree of chlorination
-log Koa = 6-8, lipophillic, but not super lipophillic (due to chlorination)
- PL (liquid vapor pressure) - indicator of volatility - -2-0, relatively volatile (extremely volatile compounds will just stay in atmosphere)
- Tc (condensation temperature) - temp at which the gas condenses to liquid - -50--10, , liquifiy and precipitate out of the air at these temps
119
What is the global distillation model?
Warm temperatures, OCs evaporate - evaporation
- OCs move in air by winds to colder places - convection
- in cold temperatures, OCs condense and fall to earth - condensation
- often happens in several jumps or bursts - known as the grasshopper effect
- more jumps are required for less volatile compounds
- results in a system where organic compounds are latitudinally fractionated according to their volatility as they condense at different ambient temperatures
120
How do the trends of PCBs in lakes vary from lakes in the arctic and in the southern US?
PCB concentration is decreasing in US lakes after banned usage - so no more input
PCB concentratino in the arctic was 0 and then starkly increased in the 2000s as chemicals migrated north in the atmosphere
121
What is the base of POP accumulation in the aquatic and terrestrial environment in the arctic?
Highly concentrated in ice / algae in the water
Concentrated in lichen on land
122
What are the overall trends in legacy and new POPs in the arctic?
Legacy POPs are slowly starting to drop, non legacy are still increasing in concentration
123
According to recent biomonitoring studies what are the effects of POPs in the arctic?
impair immune response
- oxidative stress
endocrine disruption
124
What is a biomarker?
signal at the cellular or molecular level indicating a future health outcome
- earliest effects of toxicity are seen at the smallest levels first, molecular and cellular
- if you can detect changes at the small levels you can predict the outcomes at the whole organism level
125
What were the results of the beluga whale biomarker assessment?
- more PCB =
- decreased vitA in liver, could cause growth impairment and reduced immune capacity
- plasma retinol level increased - still vit A
- increased stress is causing increased release of retinol, while decreasing the storage of vitA in the liver
- increased PCB resulted in increased Cyp1A
126
What is the RQ?
risk quitient = body residue / critical body residue
if greater than one, contaminants will have adverse effects
127
128
129
Types of biomarkers
Biomarker of exposure
- compound in blood = biomarker of internal dose
- compound in urine = biomarker of absorbed dose
- bioactivation product in blood = biomarker of effective dose
Biomarker of response - cellular / biochemical changes / changes in structure or function
Biomarker of suceptibility - seen in transition between one stage to the next (?)
130
What two radionuclides were most present after chernobyl
I-131 and Cs-134/137
131
gamma rays cause damage that originates from the ___ where x-rays cause damage that originates from the ___
nucleus, orbital electrons
132
TOX 301
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