Health assessment of emerging persistent organic pollutants (POPs) in PM2.5 in northern and central Taiwan.

Over the last two decades, Taiwan has effectively diminished atmospheric concentrations of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) through the adept utilization of advanced technologies and the implementation of air pollution control devices. Despite this success, there exists a dearth of data regarding the levels of other PM2.5-bound organic pollutants and their associated health risks. To address this gap, our study comprehensively investigates the spatial and seasonal variations, potential sources, and health risks of PCDD/Fs, Polychlorinated biphenyls (PCBs), and Polychlorinated naphthalene (PCNs) in Northern and Central Taiwan. Sampling collections were conducted at three specific locations, including six municipal waste incinerators in Northern Taiwan, as well as a traffic and an industrial site in Central Taiwan. As a result, the highest mean values of PM2.5 (20.3-39.6 µg/m3) were observed at traffic sites, followed by industrial sites (14.4-39.3 µg/m3), and the vicinity of the municipal waste incinerator (12.4-29.4 µg/m3). Additionally, PCDD/Fs and PCBs exhibited discernible seasonal fluctuations, displaying higher concentrations in winter (7.53-11.9 and 0.09-0.12 fg I-TEQWHO/m3) and spring (7.02-13.7 and 0.11-0.16 fg I-TEQWHO/m3) compared to summer and autumn. Conversely, PCNs displayed no significant seasonal variations, with peak values observed in winter (0.05-0.10 fg I-TEQWHO/m3) and spring (0.03-0.08 fg I-TEQWHO/m3). Utilizing a Positive Matrix Factorization (PMF) model, sintering plants emerged as the predominant contributors to PCDD/Fs, constituting 77.9% of emissions. Woodchip boilers (68.3%) and municipal waste incinerators (21.0%) were identified as primary contributors to PCBs, while municipal waste incinerators (64.6%) along with a secondary copper and a copper sludge smelter (22.1%) were the principal sources of PCNs. Moreover, the study specified that individuals aged 19-70 in Northern Taiwan and those under the age of 12 years in Central Taiwan were found to have a significantly higher cancer risk, with values ranging from 9.26 x 10-9-1.12 x 10-7 and from 2.50 x 10-8-2.08 x 10-7respectively.

Significant Changes of Corneal Astigmatism After Levator Muscle Surgery for Acquired Blepharoptosis.

PURPOSE: To investigate the change of corneal astigmatism after the correction of blepharoptosis. METHODS: This was a single-center retrospective cohort study conducted in Taiwan from 2017 to 2021. The medical records of patients with acquired blepharoptosis who had received levator muscle surgeries were collected. The differences in corneal astigmatism between the measurements before and at least 1 month after surgeries were investigated. Subgroup analysis of various severities of blepharoptosis and different types of corneal astigmatism was performed to determine their impacts on the axial changes after blepharoptosis surgeries. RESULTS: A total of 120 eyes of 68 patients were enrolled in this study. The mean axial change of corneal astigmatism was 17.4° after blepharoptosis surgeries, and 55 eyes (45.8%) had a change of at least 10°. In the subgroup analysis, the eyes with against-the-rule, with-the-rule, and oblique astigmatism had 42.9%, 68.4%, and 91.7% with an axial change of at least 10° after surgeries, respectively. The averaged axial change of corneal astigmatism after surgeries was 22.7° in eyes with severe blepharoptosis (margin to reflex distance1 < 1 mm), whereas it was 12.0° in eyes with mild-to-moderate blepharoptosis (margin to reflex distance1 ≥ 1 mm). CONCLUSIONS: A high proportion of eyes had a crucial axial change in corneal astigmatism after blepharoptosis surgeries, especially in those with oblique astigmatism and severe blepharoptosis. For blepharoptosis patients needing refractive surgeries or astigmatism correction with toric intraocular lens implantation, a surgical correction of blepharoptosis may be considered beforehand.