Transcript ASBESTOS - PWD

N45 – ENVIRONMENTAL
ASBESTOS CONTROL PROGRAM
LEE WILSON
NOVEMBER 2011
Reference: Overseas Environmental Baseline
Guidance Document
November 2011
N45 ENVIRONMENTAL
HISTORY OF ASBESTOS
Asbestos has been used for more than 2,000 years. It was named by the Ancient
Greeks, its name meaning "inextinguishable". The Greeks also noted its harmful
biological effects. Even though the Greek geographer Strabo and the Roman naturalist
Pliny the Elder both observed the "sickness of the lungs" in the slaves that wove
asbestos into cloth, they were in such awe of asbestos' seemingly magical properties
that they ignored the symptoms.
The Greeks used asbestos for the wicks of the eternal flames of the vestal virgins, as
the funeral dress for the cremation of kings, and as napkins. It is rumored that
Romans would clean asbestos napkins by throwing them in the fire. The asbestos
cloth would come out of the fire whiter than it went in, so the Romans named
asbestos “amiantus", meaning "unpolluted".
N45 ENVIRONMENTAL
HISTORY OF ASBESTOS
Use of asbestos declined during the Middle Ages, yet some say that Charlemagne had
asbestos tablecloths. Marco Polo was also shown items made from asbestos cloth on
his travels.
Asbestos use was brought back in the 1700s, but did not become popular until the
Industrial Revolution during the late 1800s. It then began to be used as insulation for
steam pipes, turbines, boilers, kilns, ovens, and other high-temperature products.
Ancient observations of the health risks of asbestos were either forgotten or ignored.
At the turn of the twentieth century, researchers began to notice a large number of
deaths and lung problems in asbestos mining towns. In 1917 and 1918, it was
observed by several studies in the United States that asbestos workers were dying
unnaturally young.
HISTORY OF ASBESTOS
The first diagnosis of asbestosis was made in 1924. A woman had been working with
asbestos since she was thirteen. She died when she was thirty-three years old, and an
English doctor determined that the cause of death was what he called "asbestosis".
Because of this, a study was done on asbestos workers in England. Twenty-five
percent of them showed evidence of asbestos-related lung disease. Laws were passed
in 1931 to increase ventilation and to make asbestosis an excusable work-related
disease. It would take the United States ten more years to make these steps.
N45 – ENVIRONMENTAL
ASBESTOS – BACKGROUND
Naturally Occurring Mineral Silicates: 6 types divided into 2 groups:
Serpentine:
Chrysotile
Amphiboles:
Amosite
Crocidolite
Temolite
Anthophylite
Actinolite
The most common types used commercially are chrysotile and amosite. Crocidolite has also
been used and some crocidolite has been found in housing units in Singapore.
CHARACTERISTICS
Heat Resistant
Resistant to chemicals
Long Lasting - Does not deteriorate rapidly
N45 ENVIRONMENTAL
DEFINITIONS
Asbestos Containing Material (ACM): Any material containing more than 1%
asbestos by weight.
Friable Asbestos: Any material containing more than 1% of asbestos by weight
that, when dry, can be crumbled, pulverized, or reduced to powder by hand pressure.
Category I Nonfriable ACM: Means asbestos containing packings, gaskets, resilient
floor covering, cement wall board and asphalt roofing products containing more that
one percent asbestos.
Category II Nonfriable ACM: Means any material, excluding Category I nonfriable
ACM containing more than 1% asbestos that, when dry, cannot be crumbled,
pulverized, or reduced to powder by hand pressure.
N45 ENVIRONMENTAL
DEFINITIONS
Regulated ACM: Means (a) friable asbestos material, (b) Category I nonfriable ACM that
has become friable, (c) Category I nonfriable ACM that will be or has been subjected to
sanding, grinding, cutting , or abrading or (d) Category II nonfriable ACM that has a high
probability of becoming or has become reduced to powder in the course of demolition or
renovation operations.
N45 ENVIRONMENTAL
ASBESTOS IN SINGAPORE
The initial compound building inspection was completed in 2003. Subsequent
sampling has been completed in addition to annual inspections in accordance with the
operation and maintenance plan. No friable asbestos has been identified on the
compound since 2003.
Significant improvements have been done since 2003 including abatement of transite
(cement asbestos) sheets from bus stops, the medical aid station, the battery charging
shop, Building 6-4 and One Degree North.
There is still asbestos in some housing units and the housing office informs new
residents of this issue.
N45 ENVIRONMENTAL
HEALTH HAZARDS
Asbestos causes significant health problems:
Mesothelioma – Cancer involving the mesothelium or lining of a number of internal
organs.
Lung Cancer – Incidence is greatly increased 80 -100x’s in people who smoke and
are exposed to asbestos.
Asbestosis – Scarring of the lungs resulting in diminished capacity of the lungs to
process oxygen.
Peritoneal cancer
Laryngeal cancer
N45 ENVIRONMENTAL
ASBESTOS USES
Used extensively in building materials, insulation, clutch pads, brake shoes,
fire retardant materials and materials to resist chemical degradation.
Exterior Surfaces – Roof felt, shingles, Cement Board
Insulation – Vermiculite, Batt Insulation
Floor covering – Tile (particularly 9 inch) and Vinyl Floor Covering
Interior Surfaces – Sprayed on material and textured paint
Boilers, Heating and Piping including gasket material
Electrical Equipment – Recessed lighting, wiring insulation, fuse boxes, outlets
Used in many appliances
Automotive – Brake linings/shoes, gaskets, clutch pads
N45 ENVIRONMENTAL
ROUTES OF ENTRY INTO THE BODY
Most significant is through inhalation, for asbestos, the target organs are primarily
the lungs,
Ingestion – Some risk of developing peritoneal cancers via this route.
N45 ENVIRONMENTAL
QUESTIONS
?