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Nitrogen Oxides + Hydrocarbons + Heat + Sunlight = Tropospheric Ozone

So to reduce the amount of ozone air pollution that forms in the troposphere, we must find ways to reduce emissions of nitrogen oxides and hydrocarbons from sources like vehicles and industries.

Tropospheric ozone has very different effects than stratospheric ozone. Ozone in the stratosphere protects Earth from the Sun’s ultraviolet rays (see Lesson Four). Even though only about 10% of Earth’s ozone is in the troposphere, it is here that humans and animals can breathe it in as a harmful air pollutant. Tropospheric ozone can have the following health effects, even at concentrations of just 75 parts per billion (i.e. 75 ozone molecules per 1 billion air molecules):

  1. Make people more sensitive to allergens
  2. Aggravate asthma
  3. Damage and inflame the lungs, making it harder to breathe
  4. Irritate the respiratory system - coughing and irritation in the chest

Children and the elderly are especially sensitive to these health effects. Tropospheric ozone can also interfere with photosynthesis, stunting the growth of some types of plants.

Normal lung tissue (left) and lung tissue exposed to high levels of ozone

Credit: US EPA. More information about tropospheric ozone can be found in the US EPA booklet Good Up High, Bad Nearby (http://www.epa.gov/airnow/gooduphigh).

Normal lung tissue (left) and lung tissue exposed to high levels of ozone

Credit: US EPA. More information about tropospheric ozone can be found in the US EPA booklet Good Up High, Bad Nearby (http://www.epa.gov/airnow/gooduphigh).

The Houston region has long struggled to meet federal air quality standards for ground-level (tropospheric) ozone. Large amounts of emissions from vehicles and industries (including numerous petrochemical facilities) and hot weather contribute to Houston’s ozone pollution. Though cleaner cars and industries have greatly improved ozone levels in Houston, they continue to exceed federal limits. The U.S. EPA recently lowered the ozone limit from 85 parts per billion to 75 parts per billion, because scientists found that health impacts can occur even at these low levels. This lower limit will make it even more challenging for Houston to reduce emissions sufficiently to attain the ozone standard.

In addition to tropospheric ozone, there are many other types of air pollutants that can cause harm to living things or the environment. Some air pollutants are gases that are virtually invisible. Most occur in very small concentrations (typically less than 1 molecule per million air molecules), but they can still have major impacts on our health and the environment. In Lesson 6, we will see how some of these gases can warm the planet.

Other air pollutants are particles : microscopic liquids or solids like dust or soot suspended in the air. When the air looks “hazy” like in the picture below, it is mostly due to particles scattering and absorbing light. Scientists have learned that high levels of particles in the air can cause cardiovascular and respiratory disease.

Questions & Answers

Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Rice air curriculum. OpenStax CNX. May 09, 2010 Download for free at http://cnx.org/content/col11200/1.1
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