|
Biodireito_Medicina
________________
Cigarro emite dez vezes mais particulados do que diesel com baixo teor de
enxofre
--
Cigarros s�o mais poluidores que fumos de
diesel
A polui��o emitidas por cigarros � dez vezes maior
que a exaust�o de diesel de carros, segundo estudo divulgado por pesquisadores
italianos. Eles compararam o material particulado nas exaust�es de fumos de um
carro com motor moderno, abastecido com diesel de baixos teores de enxofre, com
a fuma�a de cigarros. Tr�s cigarros, segundo os
pesquisadores, produzem dez vezes mais particulados no ar do que um ve�culo
nessas condi��es, em igni��o. �� muito surpreendente. N�o esper�vamos
esta grande diferen�a no material particulado produzido, diz Giovanni
Invernizzi, da Unidade de Controle de Tabaco do Instituto Nacional de C�ncer de
Mil�o, que conduziu o estudo. O especialista em polui��o do ar Ivan Vince, da
Consultoria Ask, de Londres, afirma que os resultados do estudo s�o razo�veis.
Ele observa que os cigarros liberam um n�mero de part�culas respir�veis superior
ao da gera��o correspondente por motores movidos a diesel com baixos teores de
enxofre.
Invernizzi e seus colegas fizeram o
experimento controlado em uma garagem privativa na pequena cidade alpina de
Chiavenna, que desfruta de um baixo n�vel de polui��o do ar
por particulados. O carro usado no experimento foi um Ford Mondeo 2002
turbo diesel, com motor contendo dois litros e que rodou por seis meses. O
ve�culo foi deixado em igni��o por 30 minutos numa garagem fechada, juntamente
com um analisador port�til de part�culas, que retirava do ar amostras, a cada
dois minutos. A garagem foi ventilada por quatro horas, depois das quais foi
fechada outra vez. Em seguida, tr�s filtros de cigarros foram queimados em
seq��ncia, num per�odo de 30 minutos. O analisador port�til
mostrou que, da queima do cigarro, resultaram dez vezes mais particulados do que
da emiss�o de fumos de diesel. (Tobacco Control, vol 13, p 219/ Newscientist,
25/8)
http://www.newscientist.com/news/news.jsp?id=ns99996312
Celso Galli Coimbra
Texto
original da reportagem
The World's No.1 Science & Technology News Service
Cigarettes more polluting
than diesel exhaust
11:20 24 August 04
NewScientist.com news service
The air pollution
emitted by cigarettes is 10 times greater
than diesel car exhaust, a small
Italian study finds.
Researchers compared the particulate matter in the
exhaust
fumes from a modern car engine, fuelled with low-sulphur
diesel,
and in cigarette smoke. Three smouldering cigarettes
produced a 10-fold
increase in air particles compared to
those produced by the idling
vehicle.
"I was very surprised. We didn't expect to find such a big
difference in the particulate matter produced," says Giovanni
Invernizzi
from the Tobacco Control Unit of Italy's National
Cancer Institute in Milan,
who led the study.
Ivan Vince, an air pollution expert from Ask
Consultants in
London, UK, says the findings are reasonable. He notes that
cigarettes give off a lot more respirable particulates than
the new
generation of low-sulphur diesels, which help cut
particulate
emissions.
Smouldering cigarettes
Invernizzi and
colleagues conducted their controlled
experiment in a private garage in the
small Alpine town of
Chiavenna, which enjoys a particularly low level of air
pollution.
The car used was 2002 Ford Mondeo turbo diesel with a
two-
litre engine, and had been on the road for six months. It was
left
idling in the closed garage for 30 minutes while a
portable analyser took
particulate air samples every two
minutes.
The garage was then aired
for four hours, after which the
doors were re-closed and three filter
cigarettes were burned
sequentially over a total of 30 minutes.
The
portable analyser showed that 10 times as many pollutant
particulates were
released in the cigarette smoke as the
diesel fumes. And the comparative
pollution levels for the
tiniest particulates - the most dangerous to health
- were
even greater.
Eye damage
"The tiny
particulates, less than 2.5 micrometres, are able
to penetrate right into
the alveoli in the lungs, where the
carcinogens do the most damage," Vince
says.
Subscribe to New
Scientist for more news and features
Related Stories
Passive smoking danger was underestimated
30 June
2004
Nano fuel additive enters efficiency trials
15
October 2003
UK aims for halving of particle pollution
17 September 2001
For more related stories
search the print edition Archive
Weblinks
Tobacco Control Unit, National Cancer
Institute, Milan
ASK Consultants
Tobacco Control
"Most of
the chemicals emitted from cigarettes are very short-
lived and so they
mostly damage the local environment. For
example, aldehydes damage plants
and peoples' eyes and
respiratory tract," he notes. Nitric oxide, also
produced by
cigarettes, is the culprit in photochemical smog and drives
ozone formation in cities.
"But with more and more people being made
to smoke outside
and in doorways, the external environmental effects must
surely rise," Vince told New Scientist.
Invernizzi is hoping his
results will provide a new weapon in
the fight against teenage smoking.
"Adolescents in Milan
campaign against pollution and for a better
environment -
often with a cigarette hanging out of their mouths. We can
show them that smoking also harms the environment."
Journal
reference: Tobacco Control (vol 13, p 219)
Gaia
Vince
-----------------------------------
Endere�os da lista:
Para entrar: [EMAIL PROTECTED]
Para sair: [EMAIL PROTECTED]
-----------------------------------
![]()
![]()
![]()
![]()
|
