Flashcards in Environmental Health Deck (50):
0
Agent that causes Chloracne ?
Dioxin
1
Bioaccumulation
- Refers to both uptake of dissolved chemicals from water and uptake from ingested food and sediment.
2
Primary air pollutants?
- SO2 (sulfur dioxide)
- NO (Nitrogen oxides)
- CO (Carbon monoxide)
- Lead
- Ozone
- Particulates (PM)
(NOx & SOx are from L.O.P, Co)
3
Stages of portable water tx?
1. Aeration - gas out
2. Coagulation
3. Flocculation
4. Sedimentation
2.3.4 - decrease bacterial burden up to 90%
5. Filtration
6. Disinfection - chlorination
Residual of chlorine for residential supplies > 0.2 mg /L
4
Recommendation on Fluoridation concentration?
0.7ppm
5
A fluoride concentration of 1.0 ppm can reduce incidence of dental caries by ? %
50-79%
6
Component of risk assessment
1. Hazard identification (HI)
2. Dose-response assessment (DR)
3. Exposure Assessment (EA)
4. Risk characterization (RC)
7
Biological oxygen demand?
A measure of organic content in water.
The greater the demand, the greater the load of organic content that can be broken down, reflecting a high bacterial load.
8
Treated sewage has a DOB of
10-20 mg/l
9
Untreated freshwater has a BOD of
25 mg/l
10
Domestic sewage has a BOD of
200-500 mg/l
11
Industrial sewage has a BOD of
>2000 mg/l
12
To monitor the safety of freshwater
Enterococcus or
E. Coli criteria
13
To monitor the safety of saltwater
Enterococcus criteria
14
Leading cause of unintentional poison death in US?
CO
15
Secondary air pollutants
- Formed after subsequent chemical reactions
- eg. Peroxyacetyl nitrate
16
Greatest single contributor to urban air pollutions is
Automobile.
17
In terms of tons of material emitted annually, in Industry, Automobiles, Electric power generators, and Refuse disposal
Automobiles contributes the most. Overall, 60% of air pollution comes from transportation.
18
The major US source of sulfur oxide air pollution is Electric power generation
Electric power generation accounts for approximately 40% of SOx emissions in the US.
19
Three primary process responsible for air pollution are
1. Vaporization
2. Attrition (in the wearing or grinding down of materials)
3. Combustion
"VAC"
20
Troposphere
- 12 mile layer that contains most of the air mass
- most of the pollution is also concentrated in the troposphere
21
Nitrogen dioxide
- Accounts for the brown haze of photochemical smog
- it reacts with organic molecules to form oxidants such as peroxyacetyl nitrate
- it also penetrates deep into the lung where it hydrolyzes to form nitric acid
22
SOx caused corrosion of buildings and statues
SOx reacts in air with moisture to form sulfuric and sulfurous acids which are corrosive
23
Aldehyde is the most reactive of organic compounds of common air pollutants
The finctional group of aldehyde is the carbonyl group (C=O) which makes these highly reactive
24
primary contributor to the formation of smog are?
Olefins (also called alkene)
25
Factors affect the dispersion of smoke plumes from a stack
1. Terrain
2. Height of the stack
3. Building nearby
Relative humidity does not affect the dispersion of the smoke plumes significantly.
26
The major source of sulfur dioxide pollution is from?
Coal fired electric power generation
- coal contains sulfur which, when burned, produced sulfur dioxide
27
The three terms used to describe plumes in air pollution are ?
1. Fanning
2. Looping
3. Coning
28
Carbon dioxide
Leads to a Greenhouse effect by causing the atmosphere to retain more of the heat from the sun.
29
Major contributor to carbon monoxide pollution is ?
- Transportation, which results in 69% of CO pollution
- Industrial processes are second
30
Eutrophication
The process in which an excess of essential elements causes a plant population explosion, leading to serious degradation of water quality.
Eutrophication is most common in lakes and ponds.
31
The most common cause of indoor air quality problem is
Poor ventilation
32
The concentration of CO2 often associated with indoor air quality complaints is greater than?
1000 ppm
The Symptoms observed are not thought to be caused by the CO2, rather the CO2 is an indicator of the buildup of other materials in the indoor air.
33
Inside a well ventilated building, CO2 level is usually about ?
600 ppm
34
The ACGIH v for CO2 is
5000 ppm
35
Hydrogen peroxide is best for killing
Bacterial spores
36
Phenol, alcohol, and halogens such as iodine are not effective against
Bacterial spores
37
EPA recommends remediation for homes with radon levels at or above ?
4 pCi/L
38
Radon
Accounts for the single largest source of ionizing radiation exposure in US, it account about 55%.
39
A Risk-Specific Dose (RSD)
- RDS is a dose that corresponds to a specific level of risk to an individual of contracting cancer over a 70-year lifetime due to the intake of contaminated drinking water.
- RDS applies to carcinogens
40
A Reference Dose (RfD)
- An RfD is an estimate of daily exposure of human population, including sensitive groups, to a substance that would not represent an appreciable risk of deleterious effects during a lifetime.
- RfD applies to non-carcinogens.
41
WHO IARC classification
Group 1: carcinogenic to human
Group 2A: probable
Group 2B: possible
Group 3: not classifiable
Group 4: probably not
42
WHO IARC classification
Group 1: carcinogenic to human
Group 2A: probable
Group 2B: possible
Group 3: not classifiable
Group 4: probably not
43
Most effective engineered water purification system for elimination of cryptosporidium is ?
Filtration
- slow sand, rapid granular, or membrane filtration is the most effective water treatment methods to remove cryptosporidium, as they are not destroyed by disinfection.
- high turbidity may affect the ability of filtration
- boiling is not an engineered water sanitation process, but it is the simplest effective method if the water is contaminated or has not been treated adequately.
- the water intended for drinking should be boiled for 1 min
- immunosuppressed persons, such as HIV, are particularly at risk of severe infection
44
Most effective engineered water purification system for elimination of cryptosporidium is ?
Filtration
- slow sand, rapid granular, or membrane filtration is the most effective water treatment methods to remove cryptosporidium, as they are not destroyed by disinfection.
- high turbidity may affect the ability of filtration
- boiling is not an engineered water sanitation process, but it is the simplest effective method if the water is contaminated or has not been treated adequately.
- the water intended for drinking should be boiled for 1 min
- immunosuppressed persons, such as HIV, are particularly at risk of severe infection
45
PCBs
- birth defects
- live cancer
46
Temperatures Inversions
- In inversion layer, Tm increase with height (normally Tm decreases with height)
- traps pollutants close to earth surface
- most common cause of air pollution disasters
47
Milwaukee Spring 1993 - 403,000 cases of Cryptosporidium due to?
Filtration failure
- Cryptosporidium oocysts are resistant to chloride treatment.
48
Public health response in disaster
Needs assessment within 24-48 hrs for natural disasters/sudden pact events
49