Health threat
In an article in the South China Morning Post on 15 August
2013 on the H7N9 bird flu, the results of a study show:
“The H7N9 bird flu that emerged on the mainland in
March may be spreading through human faeces”
In respect of these findings, Hong
Kong microbiologist Yuen Kwok-yung is quoted as saying:
"This has important implications on the infection
control strategies for H7N9 virus infection, as the influenza virus in stools
may contaminate the surrounding environment"
A copy of the article is at the bottom of the
page.
Small
house development plans in Country Park enclaves
In Hong Kong, Draft Outline Zoning Plans have
been drawn up in respect of three Country Park enclaves, Hoi Ha, Pak Lap and So
Lo Pun.
In each of the Draft Outline Zoning Plans, it
is stated there is no existing sewer or planned public sewer for the
area, and at present, each house is typically served with its own on-site
septic tanks and soakaway (STS) system. Any increase in residential
developments would require additional facilities, including their own
individual STS system, which need to comply with relevant standards and
regulations, such as EPD’s Practice Note for Professional Person (ProPECC)
5/93.
According to the relevant EPD standards and regulations
(Guidance Notes on Discharges from Village Houses), this involves dispersing
untreated wastewater into the surrounding soil and relying on the soil
to remove the polluting material from the wastewater and adequate purification
can only be achieved after the wastewater has travelled a fairly long
distance through the ground. Under Para 24 (b) of the Guidance Notes: “A
STS system is not feasible in areas with high ground water table”. Furthermore,
pollution would result if a STS is located too near to a beach or a stream. See
link to Guidance Notes on Discharges from Village Houses:
The Chairman of the Town Planning Board does not see an
issue with this. According to the Minutes of 1032nd Meeting of the Town Planning Board held on
26.4.2013, at Para 82, it is recorded:
“The Chairman said that on sewerage concern, the use of septic tanks
for sewage treatment purpose in Small House developments was common and
acceptable”
See link to Minutes of 1032nd Meeting of the Town Planning Board held on
26.4.2013:
Unfortunately, this statement is factually wrong. The use of
septic tanks for sewage treatment purpose in Small House developments, as
proposed in the Draft Outline Zoning Plans is not acceptable, because the Town
Planning Board have not been briefed about the Geological Constraints of
allowing the use of on-site septic tanks and soakaway (STS) systems in Hoi Ha,
Pak Lap or So Lo Pun and therefore do not understand, nor have they considered the
health risks associated with using STS systems in these areas.
Underlying Geology
will not support the use of on-site septic tanks and soakaway (STS) systems in
Hoi Ha, Pak Lap or So Lo Pun
The problem is the underlying surface sediment in all of
these enclaves are a combination of either alluvium, beach deposits, debris
flow deposits or estuarine and intertidal deposits. Such superficial sedimentary
deposits are porous and highly permeable and allow for rapid drainage, so no
matter how far the distance, interstices in these deposits means adequate
purification cannot be achieved through the use of on-site septic tanks and
soakaway (STS) systems.
Furthermore, because there are no restrictions on the flow
of water through such deposits, they will reflect the level of the water table
at any given time. Figure 5c (Photo 4) in TPB Paper 9368 on the Draft Hoi Ha
Outline Zoning Plan shows surface water logging, suggesting the presence of a
high water table, which means that not only should STS systems not be located
in such an area, but if they are human faecal matter will seep into the
environment. This is already happening in Hoi Ha from existing systems, as
evidenced by E. coli counts from surveys
in the bay.
Figure 5c in TPB Paper 9368 – Note the water logging in Photo 4,
suggesting the presence of a high water table
The governments own guidelines state: “A STS system is not feasible in
areas with high ground water table”.
Comment
Hong Kong’s contingency plan for pandemics is mainly geared
towards standard control measures like personal and environmental hygiene, social distancing and hospital infection
control.
If the Town Planning Board have not been briefed about the
Geological Constraints of allowing the use of on-site septic tanks and soakaway
(STS) systems in these enclaves, how can they have considered the environmental
hygiene issues. In fact, are they even aware of them?
Because of this, the Draft Outline Zoning Plans for Hoi Ha,
Pak Lap and So Lo Pun are not fit to be use as development planning documents. The government needs to withdraw these documents, go back to
the drawing board, do their homework properly and re-submit comprehensive
documents to the Town Planning Board, so that the public of Hong Kong and the
Town Planning Board are properly briefed. Only then can appropriate decisions
be made.
A good start would be for the government to pay a visit to
the Maps Publication Centre, Survey and Mapping Office, 23/F, North Point
Government Offices, 333 Java Road, North Point and buy Sheets 3, 8 and 12 of
the Hong Kong Geological Survey, then asked a trained geologist to look at the
maps of the enclave areas, then tell the government what they see.
Message to the Hong Kong Government – these are your maps and
millions of dollars were spent compiling them, so you could make informed
decisions in cases such as this. Everyone else is using them! Why aren’t you?
SCMP ARTICLE
The following is an article in the South China Morning Post
on 15 August 2013:
TEXT OF ARTICLE
H7N9 bird flu may be spread through human faeces, research suggests.
The H7N9 bird flu that emerged on the mainland in March may be spreading through human faeces, as university researchers found the virus in the stools of four out of six people killed by the bug in Zhejiang .
Theoretically, the virus could spread in the same way as severe acute respiratory syndrome (Sars) did during the 2003 outbreak in Amoy Gardens, Kowloon Bay - through sewage pipes - University of Hong Kong microbiologist Yuen Kwok-yung, a top researcher behind the cross-border study, told the South China Morning Post.
"This has important implications on the infection control strategies for H7N9 virus infection, as the influenza virus in stools may contaminate the surrounding environment," Yuen and his team reported.
But the team also suggested that the fact the virus may be transmitted via faeces was the reason why, so far, few cases of human-to-human infection had been recorded, Yuen said.
HKU conducted the joint study with Zhejiang University's First Affiliated Hospital in Hangzhou and published the results in the Clinical Infectious Diseases journal on Tuesday. They tested 12 patients who were admitted to the intensive care unit between April 10 and 23. Half of them have died.
During post-mortem tests, stool samples collected from four of the six fatalities returned positive results for the H7N9 strain.
The rate - 67 per cent - was much higher compared with those found for human flu or H5N1 bird flu, which ranged from 5 per cent to 33 per cent, the report said.
None of the blood or urine samples from the six dead patients carried H7N9. Other tissue samples, from the lung, heart, liver, kidney and bone marrow, also tested negative.
Earlier this month, Chinese researchers said their findings indicated that the H7N9 bird flu "has not gained the ability for efficient sustained transmission from person to person", although a father infected with the deadly virus was believed to have passed it to his daughter in Wuxi , Jiangsu .
In 2003, Hong Kong dealt with the deadly Sars outbreak, after it had first appeared on the mainland in late 2002.
At the Amoy Gardens housing estate 329 people were infected with Sars, of whom 42 died. The cause was traced to the sewage system which, because of its design, released the virus into the air when toilets were flushed.
It is not known whether H7N9 bird flu can be transmitted in the same way, but Yuen believed it was "theoretically possible".
"The efficiency of human-to-human transmission is very poor up until now," he said.
He stressed that the faeces of sick birds were still suspected to be the most common means by which the bird flu virus spreads.
Human waste should be handled more carefully under infection control measures, Yuen said.
The H7N9 virus was first identified in eastern China, with the first known human case reported in March. Thus far there have been 135 confirmed cases and 45 deaths.
Source
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