There are several alternative sampling and analytical methods available for the determination of respirable
crystalline silica exposure among workers. The commonly used ones are, (1) NIOSH Manual Analytical Method
No.7500(NMAM 7500) which is Silica, crystalline, by X-ray difractometer via filter deposition(NIOSH 2003), and
(2) MDHS 101 (Methods for the Determination of Hazardous Substances (MDHS) Guidance No.101: Respirable
crystalline silica in respirable airborne dust). The aim of this study is to compare applicability of respirable crystalline
silica sampling and analysis between method MDHS 101 and NMAM 7500. Laboratory procedures will be performed
strictly based on MDHS 101 and NMAM 7500. Both methods apply X-ray diffraction as analytical technique with
many variations on sampling techniques and laboratory preparations. Quality assurance values such as detection
limits, accuracy and precision are derived from both data and will be compared to determine which of the method
establishes better quality assurance. The method which establishes better quality assurance will be recommend to be
used in Malaysian respirable crystalline silica monitoring programme. The strength of this research lies on its potential
to provide local capabilities in analysis of respirable crystalline silica in Malaysian setting.
In the recent years, an extensive number of scientific researches on occupational diseases have been done to
identify occupations at high risk of inducing diseases. There are many categories of occupational diseases, and unitary
of them are occupational respiratory diseases. This study was conducted in a tea factory located in Cameron Highlands,
Malaysia, with an output of 600,000.00 kg per annum. Its objective was to evaluate respiratory diseases among the
workers, conducted via questionnaires, interviews and lung functional tests. A total of 38 workers participated in this
study, 19 in the exposed group and 19 in the control group. The most common chronic symptoms for the exposed
group are wheezing, dyspnea (short of breath) and phlegm. The result shows that, among the tea processing workers,
the exposed group suffer from respiratory diseases.
Indoor air quality is a term which refers to the air quality in and around buildings and structures, in which it
is related to the health and comfort of those who are in the building. The study aims to identify the relationship
between environmental factors with microbe growth by investigating the concentration of airborne bacteria and
fungi at National Institute of Occupational Safety and Health (NIOSH) and to determine whether indoor bacteria and
fungi concentration were associated with environmental factors such as temperature relative humidity and carbon
dioxide concentration. This research was conducted concurrently with indoor air quality sampling as per requirement
under the Malaysian Code of Practice of Indoor Air Quality (COP IAQ). The COP IAQ requires minimum of one
sample to be taken from each area. If an area consists of a few separated rooms, each room is sampled and measured
independently. Also this approach was used to determine whether there is a difference of indoor bacteria and fungi
in different microenvironments. Results show that there is a significant correlation between humidity and bacteria
concentration and fungi concentration; and between temperature and bacteria concentration. However, there is no
significant correlation between temperature and fungi concentration. This study has also established significant
difference on bacteria concentration and fungi concentration between microenvironments.
A study has been conducted on trans,trans-muconic acid (t,t-MA) as the biomarker for benzene exposure among
oil and gas petrol tanker drivers. The objectives of this study are to determine the significant difference and the
correlation between Benzene personal exposure and urinary t,t-MA among exposed and non-exposed workers. A total
of 92 questionnaires were distributed to obtain demographic and descriptive data. Benzene personal exposure was
sampled using SKC passive samplers and the data was analyzed using GC-FID. Urinary t,t-MA was collected at end of
work shift and analyzed using HPLC-UV detector. A total of 30 non-exposed workers were also sampled. The averages
of urinary t,t-MA were 96.65 ug/g creatinine for exposed workers and 0.51 ug/g creatinine for non-exposed workers.
Meanwhile, the averages of Benzene personal exposure were 0.37 mg/m3 and 0.01 mg/m3 for exposed workers and
non-exposed workers respectively. No significant correlation was found between exposure to benzene with excreted
urinary t,t-MA of workers occupationally exposed (p-value > 0.05) as well as to workers non-exposed to benzene
(p-value > 0.05). In conclusion, there is no significant correlation found between Benzene personal exposure and
urinary t,t-MA among exposed and non-exposed workers. Applicability of using t,t-MA as the biomarker of benzene
exposure shall be further discussed with all the other confounding factors to be taken into account.
Legionellosis is a respiratory infection caused by gram-negative bacteria known as Legionella. Although there are
many species of Legionella, the majority of all reported cases of legionellosis were caused by Legionella pneumophila.
Investigations of Legionella outbreaks comprised sampling building water systems for the presence of Legionella.
The aim of this study is to determine the isolation techniques with the most optimal yield for detection of Legionella
based on the Australian/New Zealand Standard Waters –Examination for Legionella (AS/NZS 3896:2008). This is an
experimental research, in which, Legionella species will be spiked in a bottle of water and various isolation techniques
will be conducted. As most cases of Legionellosis are caused by Legionella pneumophila group, this group of species
will be used.