الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
 |  | from | 153 |  |  |
| | | from | 153 | | |
Abstract
The health of women at work has become particularly important in recent years. While the role of women in maintaining the household and rearing children continues to be vital, there has been growing intemational support for their desire to play a more significant part in the socioeconomic development of their countries. Furthennore, recent studies have pointed to the need to improve the working conditions ?f gainfully employed women, who are exposed in many cOlUltries to occupational health hazards similar to men. Gender differences can influence exposure and response to workplace toxicants. Therefore, it is important to compare men and women from the anatomical, physiological, and toxicokinetic factors in order to explore differences an variations in the toxicological responses to workplace or environmental exposures. Although differences in these characteristics exist between and among men and women, it is important to note that they are not likely to impact employment, rather, they should be considered in setting occupational exposure standards. Genetic toxicology is a recent branch of toxicology that has been applied to identify and analyze the toxic action of agents directed towards the hereditary components of living system. Genotoxic substances usually have common chemical or physical properties that facilitate interaction with nucleic acids. Moreover, there is growing awareness of the great diversity of genetically active agents that exist in the lnunan environment and their differential effects on men and women health ASSays. that measure (enetic damage in hwnans can be divided into two broad categones: assays of change at the level of gross chromosomal structure (e.g. CA, MN, SCEs). assays of change at the gene level (e.g. HGPRT). ~lterest in nervous system toxicology has been growing in recent years. Thus, there has been an increase demand for improved methods for the detection of the neurotoxic effects and the assessment of health risks within the field of occupational and enviromnental health. An enzyme - linked immmlOsorbent assay (ELISA) has been developed for the early detection and quantification of autoantibody titers directed against five nervous system - specific proteins as a biomarker of neurotoxicity insult in humans. These proteins are representative of: a) the neuron - axon (neurofilament triplet proteins, NF 68, NF 160, and NF 200), b) c) the myelin sheath (myelin basic protein, MBP), and the astrocyte (glial fibrillary acidic protein, GF AP). . These autoantibodies provide infonnation on subcellular stnlctures that are targets of environmental toxic ants at subclinical levels that may not cause overt deficits for years. The present study has. been carried out to identify the genotoxic and neurotoxic effects among male and female workers occupationally exposed to Pb, Hg, and benzene. Also, to compare the results of different sexes to provide information to the work related organization regarding occupational health need for the working women. TillS study includes a total nmnber of 138 workers (67 females and 71 males) all are non smokers and showing the same demographic characteristics like age, educational status, socioeconomic status,...etc. This represents three groups of the following different exrosures: a) workers exposed to lead (26 females and 27 males) selected randomly from the Egyptian Plastic and Electricity Company in Alexandria city, b) workers exposed to mercury (21 females and 24 males) selected randomly from EI-Nasr Company for ElectrOlllc Devices (Philips) in Alexandria city, and c) workers exposed to benzene (20 females and 20 males) selected randomly from an oil refining plant in Alexandria city. Also, a matched comparison group of (61) subjects (31 females and 30 males) was selected from Edfma Company for Food Preservation. They had no history of occupational exposure to any of these pollutants, and showing the same demographic characters. as the exposed workers. The following tests have been carried out: - determination of the indices of exposures (BPb, UHg and UPh). - Somatic cell mutation analysis (MN, SCEs, and HGPRT) - Neurobiological analysis (NFs triplet proteins, MBP, and GFAP autoantibodi es ). The detennination of indices of exposures in the present study revealed that. BPb, UHg, and UPh levels were significantly increased among workers, either males or females, exposed to Pb, Hg, and benzene respectively when they were compared with that of the control subjects. These significant differences were due to occupational exposure to these pollutants. No si!:,Tniticant variations between the levels of these indices were detected due to gender difference. Somatic cell mutation results revealed that occupational exposure to Pb, Hg, or benzene resulted in a genotoxic effects among exposed male and female workers with a different response due to gender difference. T;he levels ofMN, SCEs, and HGPR T frequencies were fOlmd to be higher among exposed workers than control subj ects. ConcenIing gender difference, the present study declares that male workers exposed to Pb were more susceptible for genotoxic effects than females workers where the levels ofMN, SCEs, and HGPRT frequencies were significantly higher among male workers than that among females. However, only a significantly higher frequency ofHGPRT variant cells has been detected among male workers exposed to Hg vapour than that among exposed females suggesting that male workers were more susceptible for induction of HGPR T gene locus mutation than female workers. On the other hand, results of sex dependent genotoxic response of benzene on exposed workers revealed that the frequencies of MN and SCEs among male workers were significantly lower, while the frequency of HGPRT variant cells was significantly higher than that of female workers. These suggest that females exposed to benzene vapours were more susceptible for cytogenetic response than exposed males, whereas, exposed males were more susceptible for gene-locus mutation at HGPR T locus than females. No significant changes in the somatic cell mutation parameters were detected between male and female control subjects. Results of the present study showed that occupational exposure to Pb, Hg, or benzene resulted in a fignificantly higher percentage and / or median levels of positive titers of IgG and / or IgM AuAb isotypes against neurotypic and gliotypic proteins among male and female workers. This suggests that occupational exposure to these chemical pollutants resulted in the production of AuAb’s to NFs triplet proteins, MBP, and GFAP indicating potential biomarkers of subclinical neurotoxicity. As regards gender difference in neurotoxicity, the present study revealed that exposed females were more susceptible to neuro-axonal degeneration, whereas exposed males were more susceptible to astrocyte involvement. with myelin sheath degeneration. Also, primary Ag challenge was more predominant among exposed males, while secondary Ag challenge was predominant among exposed females. The present study concluded that occupational exposure to Pb, Hg, or benzene do have a definite genotoxic and neurotoxic effects among male and female workers with different response due to gender difference. The physiological and physical differences between gender may explain the different responses of male and female workers exposed to these industrial pollutants.^leng