Exposure to Multiple Low-Level Chemicals in Relation to Reproductive Hormones in Premenopausal Women Involved in Liquid Crystal Display Manufacture

Abstract

Background: Liquid crystal display (LCD) manufacturing involves three fabrication processes: array, panel and module processes, which result in different levels of volatile organic compound (VOC) exposure. The aim of this study was to assess the potential reproductive endocrine effects of occupational exposures during LCD manufacturing predictive of menstrual cycles as subclinical markers of female reproductive dysfunction effects of low-dose exposures. Methods: A total of 94 fabrication workers were followed for one complete menstrual cycle using daily urine samples: 23 were from the array, 53 from the panel, and 18 from the module work areas. The menstrual cycle characteristics of the study population were measured using a self-administered questionnaire. Urine samples were collected during the first urination in the morning for at least one complete menstrual cycle. The urine was then analyzed to determine the urinary concentrations of follicular stimulating hormone (FSH), estrone conjugates (E1C), and pregnanediol-3-glucuronide (PdG). The results of this analysis were used to assess the potential effects of chemical exposure as determined by handheld volatile organic compound (VOC) monitors and 24 h canisters. Results: The concentration of total VOCs was much higher in the module making area (ND–21,000 ppb) than in panel (ND–766 ppb) and array (58–1,472 ppb) making areas. The concentrations of ethanol and acetone were much higher in the module (1,974.9 and 2,283.2 ppb, respectively) and panel (2256.9 and 592.2 ppb, respectively) making areas. Compared to those in the array making area, we found that E1C (12.55, 95% confidence interval (CI): 8.49, 16.61 μg/mg Cr) and PdG (0.53, 95% CI: 0.29, 0.77 μg/mg Cr) levels in the module group were significantly higher in the early follicular phase; E1C (11.93, 95% CI: 6.21, 17.65 μg/mg Cr) and PdG (0.53, 95% CI: 0.29, 0.77 μg/mg Cr) levels were significantly higher in the periovulatory phase; and all the hormone levels, FSH (1.48, 95% CI: 0.81, 2.15 μg/mg Cr), E1C (9.29, 95% CI: 4.92, 13.66 μg/mg Cr), and PdG (1.01, 95% CI: 0.42, 1.60 μg/mg Cr) were also significantly higher in the luteal phase. In addition, the FSH (0.89, 95% CI: 0.07, 1.71 μg/mg Cr) level in the panel group was significantly higher but E1C (−4.49, 95% CI: −7.90, −1.08 μg/mg Cr) was lower in the early follicular phase; and E1C (−5.16, 95% CI: −9.61, −0.71 μg/mg Cr) level was significantly lower in the periovulatory phase. Conclusions: Our findings add to the evidence that exposure to multiple low-level chemicals is associated with modest changes in reproductive hormone urinary concentrations in healthy premenopausal women. In addition, the FSH (0.89, 95% CI: 0.07, 1.71 μg/mg Cr) level in the panel group was significantly higher but E1C (−4.49, 95% CI: −7.90, −1.08 μg/mg Cr) lower in the early follicular phase; and E1C (−5.16, 95% CI: −9.61, −0.71 μg/mg Cr) level was significantly lower in the periovulatory phase.

Faster health deterioration among nail technicians occupationally exposed to low levels of volatile organic compounds

“…as second messengers in intracellular cascades and are thus capable of modulating many intracellular processes, including inflammation and immune responses [18]. Volatile organic compounds, on the other hand, have been shown to directly interfere with dendritic cell functions, which is supposed to further modify the cellular immune response and may lead to allergic inflammation [19][20][21][22][23][24].…”

Windows of sensitivity to toxic chemicals in the development of reproductive effects: an analysis of ATSDR’s toxicological profile database

“…Numerous human epidemiological studies examined the association between environmental exposure to chemicals and menstrual cycle characteristics of exposed women (Cho et al 2001; Wennborg et al 2001; Eskenazi et al 2002; Buck Louis et al 2011; Cragin et al 2011; Lin et al 2013a, b; Lyngsø et al 2014). Several studies also attempted to link exposure of mothers during pregnancy to reproductive health of their daughters.…”

Impact of oil-related environmental pollutants on the ovary structure in the freshwater leech Erpobdella johanssoni (Johansson, 1927) (Clitellata: Hirudinea)

“…It has been shown that exposure to benzene, toluene and xylene induced pathological alterations in the earthworm Eudrilus eugeniae (Eseigbe et al 2013), whereas exposure to benzene only induced severe histopathological injuries in rat ovaries (Singh & Rana 2010). Volatile organic compounds (VOCs), especially BTEX, lead to potential damage to the reproductive and developmental health of women, resulting in preterm birth, infertility, birth defects and spontaneous abortion in women exposed to toluene and benzene in their work environment (Lin et al 2013;Webb et al 2014). Exposure to toluene and formaldehyde led to several injuries in the ovaries of adult female mice, causing disruption in the follicular growth process and alteration of their histological structure (Kareem et al 2014).…”

“…The reproductive toxicity of these compounds has recently received much attention, and many studies have been performed to address the ability of BTEX to impair reproductive functions (Chen et al 2000;Hannigan & Bowen 2010;Sirotkin et al 2012;Webb et al 2014;Djemil et al 2015). In particular, numerous studies have shown that female organisms accumulate 3.7-6.8 times more xylene than males, and ovaries are the important accumulation organ of this hydrocarbon (Suter-Eichenberger et al 1998;Wan et al 2007;Lin et al 2013).…”