03. toxicology - general.ppt
TRANSCRIPT
-
7/23/2019 03. Toxicology - General.ppt
1/40
Introduction to Toxicology
A Brief Introduction to theConcepts of Toxicology
We Will Be UsingThroughout This Course
-
7/23/2019 03. Toxicology - General.ppt
2/40
Units Used to MeasureChemicals
in the Environment
M ! arts per million
B ! arts per "illion
T ! arts per trillion
-
7/23/2019 03. Toxicology - General.ppt
3/40
A simple cu"e # cu"ic meter in
volume
#m
#m
#m
-
7/23/2019 03. Toxicology - General.ppt
4/40
Is formed of #$%%%$%%% cu"es$
# cu"ic centimeter each
#%%cm
#%%cm
#%%cm
#%%cm x #%%cm
x #%%cm $%%%$%%%cc
In # m' "loc(#cc & #ppm
-
7/23/2019 03. Toxicology - General.ppt
5/40
)ne part per million is
# inch in #* miles
# minute in t+o years
# cent in ,#%$%%%
# ounce of salt in '# tons of potatochips
# "ad apple in -$%%% "arrels of apples
-
7/23/2019 03. Toxicology - General.ppt
6/40
.ivide each #cc "loc( into
#$%%% "loc(s %/#cm on a side
#cm
#cm
#cm
%/#cm x %/#cm x
%/#cm &%/%%#cm'
In # m' "loc(
%/%%#cm' &
%/%%#cc or#pp"
-
7/23/2019 03. Toxicology - General.ppt
7/40
)ne part per "illion is
# inch in #*$%%% miles
# second in '- years
# cent in ,#%$%%%$%%%
# pinch of salt in #% tons of potato chips
# lo" in #$-%%$%%% tennis matches # "ad apple in -$%%%$%%% "arrels of
apples
-
7/23/2019 03. Toxicology - General.ppt
8/40
And divide each %/#cc "loc(into #$%%% "loc(s %/%#cm
on a side
%/#cm
%/#cm
%/#cm
%/%#cm x %/%#cm
x %/%#cm &%/%%%%%#cm'
In # m' "loc( /
%%%$%%%$%%#m' &%/%%%$%%#cc or
#ppt
-
7/23/2019 03. Toxicology - General.ppt
9/40
)ne part per trillion is
# postage stamp in the area of the city of.allas
# inch in #* million miles 0more than *%%times around the earth1
# second in '-% centuries
# flea on '*% million elephants # grain of sugar in an )lympic si2ed pool
# "ad apple in - "illion "arrels
-
7/23/2019 03. Toxicology - General.ppt
10/40
Important Concept
)n the left side of the decimal point 0/ 1! # trillion is "igger than # "illion
! # "illion is "igger than # million! # million is "igger than # thousand3
)n the right side of the decimal point 0 / 1! # part per trillion is smaller than # part per "illion
! # part per "illion is smaller than # part per million
! # part per million is smaller than # part perthousand
-
7/23/2019 03. Toxicology - General.ppt
11/40
Important 4elationship
5or +ater at 6T 0standard temperature7-'oC8 and pressure 7#9 psi81
1 cc = 1ml = 1g
-
7/23/2019 03. Toxicology - General.ppt
12/40
Which means that
# liter of +ater & # (g
# mg : (g & # ppm
#mm3: liter & # ppm
# mg : liter & # ppm
-
7/23/2019 03. Toxicology - General.ppt
13/40
Measures of Toxicity
Toxicity of chemicals is determined in thela"oratory
The normal procedure is to expose testanimals! By ingestion$ application to the s(in$ "y inhalation$
gavage$ or some other method +hich introduces
the material into the "ody$ or! By placing the test material in the +ater or air of
the test animals; environment
-
7/23/2019 03. Toxicology - General.ppt
14/40
Measures of Toxicity
Toxicity is measured as clinical
-
7/23/2019 03. Toxicology - General.ppt
15/40
Measures of Toxicity@
The Median ?ethal .ose
LD50
The amount 0dose1 of a chemical +hich producesdeath in 9% of a population of test animals to+hich it is administered "y any of a variety of
methods
mg/kg
>ormally expressed as milligrams of su"stance per(ilogram of animal "ody +eight
-
7/23/2019 03. Toxicology - General.ppt
16/40
Measures of Toxicity@The Median ?ethalConcentration
LC50
The concentration of a chemical in an environment0generally air or +ater1 +hich produces death in9% of an exposed population of test animals in a
specified time frame
mg/L
>ormally expressed as milligrams of su"stance perliter of air or +ater 0or as ppm1
-
7/23/2019 03. Toxicology - General.ppt
17/40
rimary 4outes of Exposure
to esticidesThere are three primary routes "y +hich
organisms are exposed to pesticides
)ral
.ermal
Inhalation
-
7/23/2019 03. Toxicology - General.ppt
18/40
rimary 4outes of Exposure@
)ral Exposure
Any exposure to pesticide +hich occurs +hen
the chemical is ta(en in through the mouthand passes through the gastrointestinal tract
.uring oral exposure$ although carried +ithinthe "ody$ the pesticide is still outside of the"ody cavity
-
7/23/2019 03. Toxicology - General.ppt
19/40
rimary 4outes of Exposure@
.ermal Exposure
Exposure of the s(in to a pesticide
Most common route of human exposure
With proper hygiene this type of exposure isgenerally not serious unless there is aspecific$ rapid toxicological effect 0often eyeeffects1 +hich is of concern
-
7/23/2019 03. Toxicology - General.ppt
20/40
rimary 4outes of Exposure@
Inhalation Exposure)ccurs +hen a pesticide is "reathed into the
lungs through the nose or mouth
6ignificant route of exposure for auaticorganisms
>ot of toxicological concern until it crosses fromthe lung into the "ody 0unless the chemical iscorrosive1
-
7/23/2019 03. Toxicology - General.ppt
21/40
.uration of Exposure
Three terms are commonly used todescri"e the duration of dose0s1
Acute
Chronic
6u"chronic
-
7/23/2019 03. Toxicology - General.ppt
22/40
.uration of Exposure@
Acute Exposure
Application of a single or shortterm
0generally less than a day1 dosing "y achemical
If toxic symptoms are expressed$ they arereferred to as symptoms of
-
7/23/2019 03. Toxicology - General.ppt
23/40
.uration of Exposure@
Chronic Exposure
Expression of toxic symptoms only after
repeated exposure to a chemical in dosesregularly applied to the organism for a timegreater than half of its lifeexpectancy
If toxic symptoms are expressed$ they arereferred to as symptoms of
-
7/23/2019 03. Toxicology - General.ppt
24/40
.uration of Exposure@
6u"chronic Exposure
Toxic symptoms are expressed after repeated
applications for a timeframe less than half thelife expectancy of the organism ! "ut moreoften than a single dose or multiple dosesapplied for only a short time
If toxic symptoms are expressed$ they arereferred to as symptoms of
-
7/23/2019 03. Toxicology - General.ppt
25/40
4emem"er !
5or pesticides ! less is more +hendealing +ith toxicity
The less you need to cause a toxiceffect ! the more toxic the su"stance is
Thus an ?.9%of -9 mg:(g is more toxic
than is one of D$%%% mg:(g
-
7/23/2019 03. Toxicology - General.ppt
26/40
Words again
Safe
Low Risk
-
7/23/2019 03. Toxicology - General.ppt
27/40
6ignal Words
The relative acute toxicityof a pesticide is reflectedon the la"el in the form of a
WA4>I>
.A>E4
-
7/23/2019 03. Toxicology - General.ppt
28/40
6ignal Words@
CAUTI)>
-
7/23/2019 03. Toxicology - General.ppt
29/40
6ignal Words@
WA4>I>
-
7/23/2019 03. Toxicology - General.ppt
30/40
6ignal Words@
.A>E4
-
7/23/2019 03. Toxicology - General.ppt
31/40
)I6)>GGG
?egally defined term ! not Hust anything youdon;t li(e
Any pesticide +ith an ?.9%of 9% mg:(g or less ?a"els must reflect this classification
?a"el must have the signal +ord E4=plus the +ord =
?a"el also must display the s(ull andcross"ones icon
-
7/23/2019 03. Toxicology - General.ppt
32/40
4elative toxicity
)rganisms can;t differentiate "et+een
-
7/23/2019 03. Toxicology - General.ppt
33/40
4elative toxicity
Most her"icides act on "iological path+aysnot present in humans
Those approved for use in the 4egion 0muchmore a"out these laterGG1 have ?.9%s of 9%
mg:(g or greater ! they have intermediate orrelatively lo+ toxicity
6ome of the insecticides used are highlytoxic
-
7/23/2019 03. Toxicology - General.ppt
34/40
4elative toxicity
6ome examples of pesticides and otherchemicals are given to sho+ relative ris( of
pesticides in the environment in +hich +e live This is >)T to triviali2e the pesticides
Al+ays treat them +ith caution and respect
But$ have a realistic recognition of theirrelative ris( in a +orld of ris(s
-
7/23/2019 03. Toxicology - General.ppt
35/40
4elative toxicity@
Insecticides
TC.. 0.ioxin1 %/# mg:(g
arathion #'/% mg:(g
>icotine 9%/% mg:(g
Car"aryl -D%/% mg/(g Malathion 'D%/% mg:(g
-
7/23/2019 03. Toxicology - General.ppt
36/40
4elative Toxicity@
er"icides and Additivesmg:(g
arauat J9
-$K. 'D9-$K. 9'-
Triclopyr *'%
Te"uthiuron *KK
.icam"a D9Dexa2inone #$*J%
lyphosate K$'-%
mg:(g
?imonene 9$%%%
Clopyralid F9$%%%6ulfometuron Met// F9$%%%
Ima2apyr F9$%%%
.iesel oil D$'L%
icloram L$-%%5osamine am// -K$K%%
erosene -L$%%%
-
7/23/2019 03. Toxicology - General.ppt
37/40
4elative Toxicity@
Comparative informationighly toxic chemicals
% ! 9% mg:(g range
0taste # teaspoonful1mg:(g
Botulinus toxin %/%%%%#
.ioxin %/#
arathion #'/% 6trychnine '%/%
>icotine 9%/%
Moderately toxic chemicals
9% 9%% mg:(g range
0teaspoonful # ounce1mg:(g
arauat J9
Caffeine -%%
Car"aryl -D% Malathion 'D%
-$K. 'D9
-
7/23/2019 03. Toxicology - General.ppt
38/40
4elative Toxicity
Comparative Information6lightly toxic chemicals
9%% ! 9$%%% mg:(g range
0# ounce # pint1mg:(g
-$K. 9'-
Triclpoyr *'%
Te"uthiuron *KK .icam"a D9D
mg:(g
5ormaldehyde L%%
exa2inone #$*J% Asprin #$D%%
Nitamin B' #$D%%
ousehold "leach -$%%%
Ta"le salt '$D9% lyphosate K$'-%
etc/
-
7/23/2019 03. Toxicology - General.ppt
39/40
4elative Toxicity@
Are all su"stances toxicOPE6G
All are toxic to some uantifia"le degree6ugar has an ?.9%of '%$%%% mg:(g
The foresters favorite ! ethanol has an ?.9%
of only #'$D%% mg:(gEven +ater has a recogni2ed ?.9%of slightly
greater than L%$%%% mg:(g
-
7/23/2019 03. Toxicology - General.ppt
40/40
4elative Toxicity@
The ?ast Wordesticides are chemicals introduced into the
environment to perform a function
The source of a chemical 0synthetic vs/natural1 is irrelevant +hen considering itstoxicity
esticides should "e treated +ith care andproper respect ! "ut so should householdcleaners$ gasoline and (erosene$ "leaches$paints and all other chemicals