Carbon monoxide poisoning
on paris territory - n° 701
Loïc PAILLAT, Eddie FAURE, Monique AYOUBI, Ghislaine GOUPIL, Claudine DELAUNAY
Laboratoire Central de la Préfecture de Police, 39bis rue de Dantzig 75015 PARIS, France - www.lcpp.fr
Introduction
results
In France carbon monoxide (CO) is the leading cause of death by poisoning.
On Paris territory, the Central Laboratory of the Police headquarters (LCPP) performs an environmental
survey each time a case of carbon monoxide poisoning is suspected by emergency services.
Most of carbon monoxide poisoning occurred during the heating season (80% from January to March
and from October to December). Nowadays, on Paris territory, the major sources of domestic carbon
monoxide poisoning are gas boilers and water-heaters connected to a chimney flue.
Statistics and evolution of appliances responsible
for CO poisoning - Number of investigations 1979 - 2008
More than 3000 investigations have been handled since 1990 by LCPP on Paris territory.
The carbon monoxide poisonings caused 250 deaths ; 7300 people were hospitalised and some of
them remained aftereffects.
The aim of this study is to establish the statistics and evolutions of appliances and technical failures
responsible for carbon monoxide poisonings over the last twenty years.
materials - methods
At the national level, the supervision system of the poisonings by carbon monoxide has been improved,
since January 1st, 2005.
Data from this carbon monoxide poisoning surveillance system aim to targeting public health actions,
as well as assessing their impact in time and space.
In any case, an accident is always the conjunction of
technical failures and human factors. In some cases, weather
conditions can facilitate carbon monoxide poisoning.
Statistics on technical failures
Prevalence (%)
The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea….
These signs are variable and non-specific and may easily be confused with those of other disorders.
This explains why a CO poisoning can be difficult to diagnose.
High levels of CO inhalation can cause loss of consciousness and death.
A survey is conducted as quickly as possible in the following cases reported by emergency services :
• suspicion of carbon monoxide poisoning
• carbon monoxide concentration measured in the atmosphere of a home equal or greater than
10 µmol.mol-1
• carboxyhemoglobin level equal or greater than 6% in an active smoker or 3% among non-smokers.
These investigations allow the identification of the source of carbon monoxide, to take safety measures
and to bring into conformity the installations involved.
Carbon monoxide is measured using a non-dispersive infrared spectrometric method (NDIR).
There are many causes of inadequate chimney performance
or failure :
• lack of maintenance - obstructions such as soot and
broken bricks can block a chimney’s air flow,
• a chimney may be improperly sized — too small to
maintain an adequate draft,
Chimney’s air flow blocked by bricks
• an uninsulated chimney on an exterior wall is particulary
hazardous because it may become very cold when
combustion gases are not present. When the chimney first
fills with moist combustion gases, the condensation may
increase, at least until the chimney warms up. This in turn
leads to problems such as leaks, blockages, and poor draft.
When ventilation equipment, such as a hood or a ventilation
fan, is used in a tightly sealed home, reverse air flow can
occur in chimneys and flues.
Chimney too small to maintain an adequate draft
Reverse air flow by a hood
Draft test with a smoke tube.
Contrary to generally accepted ideas, these accidents do
not occur only in disadvantaged environment and degraded
housing. Given the poor economic climate, the number of
poisoning with charcoal or barbecue grill used for heating
inside homes is higher today than in 1979.
Carbon monoxide and carbon dioxide analyzers
Barbecue grill used as home heating
Conclusions
On Paris territory, 90 % of carbon monoxide poisonings occurred in dwellings.
The technical improvements of devices and the evolutions of the regulation explain the changes observed in the type of appliances involved for these accidents.
Lack of maintenance to appliances and flues and lack of ventilation seem to be the main factors facilitating carbon monoxide poisoning.
These results highlight the need to set up studies to better understand the mechanisms involved in carbon monoxide poisoning, and develop public health actions
through regulatory or educational means.
Corresponding email : [email protected]
12th International Conference on Indoor Air Quality and Climate - 5-10 June 2011. Austin, Texas - USA