11 gaseous pollutants II Flashcards
how many cases of lung cancer is caused by air pollution in the UK?
what are some important secondary air pollutants?
-ground level ozone (O3) (highly oxidizing reagent)
-acid rain (H2SO4, HNO3)
what is ozone?
-normal component of the stratosphere
ozone reacts with chlorofluorocarbons (CFCs) and is annihilated
-less stratospheric ozone leads to reduced protection from UV
-ground level ozone is a pollutant and is toxic
what are the toxic effects of ground level (tropospheric) ozone?
animals
-extensive damage to vital cellular proteins and enzymes, DNA (chronic bronchitis, congenital abnormalities, neonatal death)
what is the formation of photochemical smog (ground level ozone)?
-NO2 is photosensitive so breaks down into NO and O in presence of sunlight but it is a reversible process so it is not very stable (NO2<–>NO+O)
-VOC has very high affinity for nitrogen oxide
VOC+NO->PANs+aldehydes
-since NO conc goes down, NO2<–>O+NO, the singlet oxygen binds with O2 in the atmosphere to form ozone
-ozone is more of a problem in big cities because there are more primary pollutants (NO, CO2, HC)
-eye irritation is caused by PANs in big cities
what is temperature inversion?
temperature inversion can prolong photochemical smog
-cool air close to ground gets trapped there by warm air
-problem: cold air is heavy
-when smog occurs it sits there for several days
what are the ozone hotspots in north america?
over 60ppb is bad for human health
-concentration of big cities
how far can acid rain travel in the atmosphere?
can travel up to 1500km in the atmosphere
-gases+water from atmosphere=acid
-landscape getting acid rain=changes pH of systems
what does acid deposition lead to?
forest decline (deforestation)
-damage to leaves=decreased photosynthesis=decreased growth
-reduces fertility of soil
-hurts symbiotic relationships with fungi and bacteria with plant
-acid increase the solubility of metals (increases toxicity)
-therefore, plants become more susceptible to environmental stressors
what are the effects of acid deposition?
-deforestation
-loss of soil fertility
-declining aquatic species diversity
-loss of prey abundance, affecting the food web
what is a case study of acid rain in canada?
why there is only perch (very acid tolerant)
-doesnt look like this anymore but takes a long time to recover
what is the acid rain treaty?
-treaties between USA and canada from decades ago (1991) have limited emissions
-acid rain is no longer considered a threat in eastern canada (in 70s-90s it was a major problem)
what were the changes from 1990 to 2005
what is the long-term atmospheric trends in primary air pollutant in canda?
what are the canadian national ambient air quality objectives?
what is the air quality health index (AQHI)?
a scale designed to help you understand what the air quality around is means to our health
-it measures the air quality in relation to our health on a scale from 1-10
how is AQHI calculated?
-calculated based on the relative risks of a combination of common air pollutants that are known to harm human health
these pollutants are:
-ozone (O3) at ground level
-particulate matter (PM2.5/PM10)
-nitrogen dioxide (NO2)
what is AQI in USA?
