Hello everybody my name is Zohir Chowdhury, and today's topic is about criteria air pollutants
with focus of lead and carbon monoxide so we know that there are six criteria air pollutants they
are led carbon monoxide nitrogen oxides sulfur oxides ozone particulate matter PM 10 and PM 2.5
today we'll focus on lead and carbon monoxide two of the criteria air pollutants so what is led led
is a chemical is naturally occurring and sources of environmental add include leaded gasoline that
is used for fueling purposes can also be in the tap water from solder pipes that are made of lead
as well as usage of later'd batteries and in old buildings paints were made with lead and so old
buildings painted surfaces may contain light other sources of light can be imported para pottery that
is using for service sometimes also like candy is imported from Mexico have been known to have lead
and there are other light sources as well so let acid batteries which are shown here to the left
is used in automobiles and in the past we used to see many of the lead acid batteries in landfills
which causes LED to be leaked leached into the environment and into the soil and contaminate
the soil and the groundwater leaded gasoline it's shown here these are very old refueling stations
that used to contain lead right now all of the leaded gasoline in most of the countries around
the world have been replaced with what we call unleaded gasoline so let it gasoline have been
has been replaced with unleaded gasoline and you can see here leaded petroleum phase-out Globalstar
status as of 2016 from the UNEP report US has been has completely phased out many many years
back Europe as well and you can see almost all of Asia as well except for a few countries here
so we have Algeria Yemen and Iraq three countries that still has both leaded and unleaded gasoline
in country and this definitely leads to led to be airborne because as let get combusted
into your vehicle lead oxide comes out in the in their other sources of lead is plumbing such as
this one shown in ancient Rome they were made of lead however since the 1950s of sixties I
believe leaded pipes or even later other paths have been replaced with copper pipes because
of the specific issues that lad has in addition lad can also be used in paint especially older
buildings this is an old buildings and you can see pink that is chipping from the outdoor and
paint chipping in the indoor this paint had led so because of the lead in the paint and
the paint chipping it can become airborne so why is it so much of concern LED in the air or LED
in the environment as and it can be in the water it can be in the soil it can be the food as well
that can cause serious central nervous system damage especially in children because they have
a growing nervous system and with repeated light exposure that growing nervous system can become
problematic so with lead poisoning children may seem a display different types of problems
throughout the entire life because of and not a properly develops central nervous system so
there been a lot of studies with LED exposure and children in here you can see the different
types of behavior in here that are displacing that are displayed in children and in red are
children whose denting led led in the teeth is higher than 27 ppm and here in light blue you can
see while turquoise you can see dentin lad that is less than five point one ppm and so tooth as
you probably know they fall in children and as this slowly they lose the baby teeth and so this
in this study the teeth sample from children have been collected and analyzed for lat so students
with children that have higher lead in the teeth which equates to higher light exposure display
significant distractibility not being persistent being dependent being more hyperactive as well as
more frustrated or being more of a daydreamer and the list goes on as compared to students
or children that had a lot less lead exposure in their teeth other studies are shown to the
right this is childhood childhood lead exposure and intelligence and it's been shown that with
ten deciliter increase so 10 microgram per deciliter of blood increase of lead has been
shown to cause significant drop of lad and you can see this chart where IQ score are progressively
declining with increased lead exposure so going back to increased lead exposure so in here from
10 microgram per deciliter to 20 micron per deciliter lead increase leads to significant
IQ drop as much as 5.6 IQ points drop in the IQ skill and we know that 100 in the IQ skill special
in the IQ standard Bennett's skill is known to be average so someone that has a hundred ten which
is above average IQ can drop almost ten points by increasing lead from 10 to 20 20 to 30 microgram
per deciliter because of all of these issues that we have been that we've just introduced
Ladd has been slowly banned in the u.s. here we can see led man in the paint then led ban in the
gasoline and then soldered led ban which led to let concentration in the blood from 16 milligram
per deciliter to as low as 2 and it's continually declining in the US the next criteria pollutant
that we will introduce is carbon monoxide and carbon monoxide is colorless odorless tasteless it
is produced as a result of incomplete combustion and for those of you that are kept at a chemical
inclined here you can see that carbon in the fuel it's burned in the presence of oxygen and used to
carbon monoxide when there's not enough oxygen but with more oxygen it becomes carbon dioxide
so complete combustion of fuel leads to carbon dioxide concentration being released chemical
been released whereas if you have incomplete combustion where there's not enough oxygen you
may have significant carbon monoxide CO being reached sources of carbon monoxide are mostly
Motor Vehicles but also home appliances heating appliances releases carbon monoxide and there
may be other combustion sources as well that can release carbon monoxide especially when there's
more incomplete combustion going on health outcome carbon monoxide has higher affinity to hemoglobin
than oxygen in fact 240 times more higher affinity to hemoglobin than oxygen so it quickly replaces
oxygen in the blood and we can see in here a chart carbon monoxide in the atmosphere in ppm
for example and equivalent carboxy hemoglobin in the blood so at 70 ppm born dioxide in the
air can lead to blood carboxyhemoglobin level of about 10% and you can see the Associated
physiological and subjective symptoms as ppm concentration in the air increases so does the
carboxy hemoglobin in the blood and you can see that the health effects slowly deteriorates form
shortness of breath to headaches to confusion and progressively can become fatal so carboxy
hemoglobin concentration in nonsmoker typically relatively low about 2% carboxyhemoglobin or less
in the blood but who to nonsmoker carboxyl mclogan can be two smokers cavity mclogan
can become as high as 4% or with heavy smoking as much as 15% and in this diagram you can see carbo
carboxyhemoglobin slowly replacing oxygen and causing the binding of carbon carbon monoxide
with hemoglobin and as a result causes oxygen to be depleted and you become asphyxiated alright so
this is the end of our criteria air pollutants discussion on LED and carbon monoxide thank you