Smells again

WHAT IS THAT ROTTEN SMELL ?
The rotten smell wafting through
your window is hydrogen sulfide gasses
that are the product of decomposing algae
and dead vegetation in CV Lake.

The sun sparkling on the waters of
our lake is a wonderful sight. But the
beauty is belied by a closer look at the
slimy green water and the rotting algae
that rings the lake. The most objectionable
thing about it is the smell that wafts
throughout the village as the algae rots in
the sunshine.

Efforts have been made to fix it.
Aerators that bubble air into the water in
an attempt to clean it up have been installed
and there is talk of adding carp to
the lake who will hungrily devour the
green slime that coats the bottom, clouds
the water, then dies away and floats
around rotting. Carp are known to eat
algae but prefer succulent water plants
and small aquatic organisms

The rotting algae is not just contained
in the lake. Irrigation sprinklers,
spray water and the algae it contains all
around the village. Residents are aware
of the objectionable smell, but are they
aware of the potential health hazards of
exposure to the Cyano-bacteria that
come with the algae?

The chart below shows the whole
effects of exposure to hydrogen sulfide
gas. The levels in the air around Century
Village are fairly low and are not likely
to cause the extreme symptoms caused
by exposure to high levels.

Summer will soon be here and the
warm weather can only make the rotten
smell worse as the algae thrives.

Hold your nose and get an air
freshener, it’s about all you can do to
avoid the rotten smell from the CV Lake.

Concentration (ppm) Hydrogen Sulfide
Symptoms/Effects

0.00011-0.00033 Typical background concentrations
0.01-1.5 Odor threshold (when rotten egg smell is
first noticeable to some). Odor becomes more offensive
at 3-5 ppm. Above 30 ppm, odor described as
sweet or sickeningly sweet.

2-5 Prolonged exposure may cause nausea, tearing
of the eyes, headaches or loss of sleep. Airway problems
(bronchial constriction) in some asthma patients.
20 Possible fatigue, loss of appetite, headache, irritability,
poor memory, dizziness.

50-100 Slight conjunctivitis ("gas eye") and respiratory
tract irritation after 1 hour. May cause digestive
upset and loss of appetite.

100 Coughing, eye irritation, loss of smell after 2-15
minutes (olfactory fatigue). Altered breathing,
drowsiness after 15-30 minutes. Throat irritation
after 1 hour. Gradual increase in severity of symptoms
over several hours. Death may occur after 48
hours.

100-150 Loss of smell (olfactory fatigue or paralysis).
200-300 Marked conjunctivitis and respiratory tract
irritation after 1 hour. Pulmonary edema may occur
from prolonged exposure.
500-700 Staggering, collapse in 5 minutes. Serious
damage to the eyes in 30 minutes. Death after 30-60
minutes.

700-1000 Rapid unconsciousness, "knockdown" or
immediate collapse within 1 to 2 breaths, breathing
stops, death within minutes.

US. Department of Labor Occupational Safety and Health