| Author | Chate Jaikunya |
| Call Number | AIT Thesis no.EV-01-5 |
| Subject(s) | Styrene--Health aspects
|
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of
Science.
Inter-University Program on Environmental Toxicology, Technology and Management, School of Environment, Resources and Development |
| Publisher | Asian Institute of Technology |
| Abstract | Due to the high exposure of styrene in many occupational settings, to study the amount of
styrene exposure in term of both external and internal doses in relate to the potential adverse
health effect would be relevant to assessing and preventing workers from exposure to this
chemical.
The objective of this research is to study the levels of exposure to styrene and its possible
health effects in workers in the reinforced-plastic manufacture. Biological monitoring of
exposure to styrene in the workplace is an important component of this study.
Firstly, the measurement of styrene in workplace was conducted and the means detected level
was 18.96 µg/L. This level indicated the low level when compared with the recommended
level (TWA). The external dose or exposure level was measured as the level of styrene in the
breathing zone of workers, and mean level was 32.74 µg/L. The internal dose levels were
determined in the blood and urine of workers and control people. In the blood samples of
workers styrene was found at the means levels of 163.41 µg/L, but it was not detected in the
control blood sample. The comparison of the styrene levels in the breathing zone and in the
blood showed a significant conelation in the workers.
The urine was used for the determination of styrene's metabolites, Mandelic acid (MA) and
Phenlyglyoxylic acid (PGA). In both workers and the control groups a high variation of MA
levels, both in the beginning and the end of workshift was found. The means MA level in the
workers at the beginning of the workshift was 1,142 mg/g creatinine, and at the end of the
workshift was 2,247 mg/g creatinine. In the control group, the means MA level at the
beginning ofworkshift was 795 mg/g creatinine, and at the end of workshift was 1,348 mg/g
creatinine. The results of PGA levels also showed a high variation in workers but PGA was
not detected in the control group, at the beginning of workshift found 30 mg/g creatinine, and
at the end ofworkshift found 43 mg/g creatinine. The results of MA and PGA levels showed
no conelation with styrene levels in the breathing zone and in the blood. However, significant
correlation was observed with Spearman coefficient between; MA at the beginning and at the
end of the workshift (r = 0.51 ), PGA at the beginning and the end of workshift (r = 0. 77), and
MA and PGA at the end ofworkshift (r = 0.40). The high variation of urinary metabolites can
be explained by individual variation in the metabolic rate in the body, therefore the
interpretation of urinary metabolites with the levels of styrene in breathing zone and blood
required the collection of urine sample throughout the entire workshift and pathways extended
to 24 hours. In addition, the assessment of possible health effects associated with styrene
exposure on the several organ functions should be added in the surveillance program for
workers in this manufacture. These are lung function test, the measurement of aspartate
aminotransferase (AST) and alanine aminotransferase (ALT) levels, and erythrocyte
sedimentation rate (ESR) values. |
| Year | 2001 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Environmental Engineering and Management (EV) |
| Chairperson(s) | Khunying Mathuros Ruchirawat |
| Examination Committee(s) | Samom Muttamara ;Panida Navasumrit
|
| Scholarship Donor(s) | King Scholarship |
| Degree | hesis (M.Eng.) - Asian Institute of Technology, 2001 |