16-01-2014, 04:59 PM
Contaminated Water Diving (CWD)
Contaminated Water .pdf (Size: 2.48 MB / Downloads: 34)
Difinition:
-Contaminated water is defined as water which contains any chemical, biological, or
radioactive substance which poses a chronic or acute health risk to exposed
personnel.
GENERAL:
-The three types of contaminants Divers can expect to encounter are :
chemical, biological, and radiological.
-The potential routes of exposure for Divers are:
inhalation, ingestion, absorption, and impingement (forcing of material into the body,
such as through a wound).
-If a specific contaminant is suspected, information from various sources is available such as
Material Safety Data Sheets (MSDS), shipping manifests, or sampling and analysis.
Fecal contamination :
-Fecal contamination includes bacteria (Escherichia coli, Campylobacter) viruses
(Polioviruses, Hepatitis A), parasitic protozoa (Cryptosporidium parvum, Giardia lamblia)
and helminths (Ascaris)
-Health problems associated with fecal contamination are
gastroenteritis, diarrhoea and vomiting, respiratory diseases, hepatitis, dysentery,
anaemia, poliomyelitis and ascariasis.
-Divers using regular diving gear (scuba divers) are exposed to fecal contamination as
microorganisms may enter the body through the
nose, the ears, the mouth and open wounds, because the wet suit does not protect the
skin .
Free-living organisms :
- Vibrio species are naturally present in marine environments, in both temperate and tropical
waters . Infections due to Vibrio species are both intestinal and extraintestinal (infection
of open wounds).
-Aeromonas species are considered to be ubiquitous in both fresh and marine waters,
with high numbers occurring during the warmer months of the year.These species play a
role in enteric illnesses, although they are generally self-limited.
-Free-living amoebae are common to soil and aquatic environments. They can cause
serious illnesses often with fatal consequences.( encephalitis, keratitis, and
meningoencephalitis)
Inorganic contaminants:
-The most toxic inorganic contaminants are heavy metals although other contaminants
such as nitrite, nitrate, cyanide, and fluoride may cause health effects if they are present
in high concentrations. Some of the metals are insoluble (mercury, lead) and are associated
with particles. Therefore they will be a concern if working with sediments.
-It is also the case for tributyltin (TBT) compounds which is widely used in anti-fouling paint
in order to slow the growth of organisms that attach to the hull. According to NOAA (2004),
TBT is a very toxic compound which is commonly found in the bottom of harbours and working
with sediments may cause a risk, particularly if they are contaminated with TBT.