Dry eye disease (DED) has become a common eye disease in recent years and appears to be influenced by environmental factors. This study aimed to examine the association between the first occurrence of DED, air pollution and weather changes in Taiwan. We used the systematic sampling cohort database containing 1,000,000 insureds of the National Health Insurance of Taiwan from 2004 to 2013, and identified a total of 25,818 eligible DED subjects. Environmental data, including those of air pollutants, temperature and relative humidity, were retrieved from the environmental monitoring stations adjacent to subjects’ locations of clinics as exposure information. We applied the case-crossover design, which used the same subjects experiencing exposures on diagnosis days as cases and those on other days as controls. The descriptive statistics showed that the first occurrences of DED were the most for the elderly by age (53.6%), women by gender (68.9%), and spring by season (25.9%). Multivariate conditional logistic regression analyses indicated that carbon monoxide (CO), nitrogen dioxide (NO₂), and temperature were positively associated with DED (p < 0.05), while relative humidity was negatively related (p < 0.001). Because CO and NO₂ together are considered a surrogate of traffic emission, which is easier to control than the uprising temperature, it is suggested that efficient management and control of traffic emission may lower the probability of DED occurrence.

The collapse of the World Trade Center (WTC) on September 11, 2001, generated large amounts of dust and smoke that settled in the surrounding indoor and outdoor environments in southern Manhattan. Sixteen dust samples were collected from undisturbed locations inside two uncleaned buildings that were adjacent to Ground Zero. These samples were analyzed for morphology, metals, and organic compounds, and the results were compared with the previously reported outdoor WTC dust/smoke results. We also analyzed seven additional dust samples provided by residents in the local neighborhoods. The morphologic analyses showed that the indoor WTC dust/smoke samples were similar to the outdoor WTC dust/smoke samples in composition and characteristics but with more than 50% mass in the 50% of mass above >53 μm. Elemental analyses also showed the similarities, but at lower concentrations. Organic compounds present in the outdoor samples were also detected in the indoor samples. Conversely, the resident-provided convenience dust samples were different from either the WTC indoor or outdoor samples in composition and pH, indicating that they were not WTC-affected locations. In summary, the indoor dust/smoke was similar in concentration to the outdoor dust/smoke but had a greater percentage of mass <53 μm in diameter.

We conducted a pilot study to examine the relationship between organophosphate (OP) and pyrethroid (PYR) insecticides in blood and their metabolites in urine. A total of 30 pregnant women were enrolled in the study, and blood and urine was sampled from each subject during a regular clinic visit. Two OP and nine PYR insecticides were selected for blood sample analysis, while six OP and five PYR metabolites were analyzed for urine specimens. Both types of samples were processed and analyzed on gas chromatography-mass spectrometry. For OPs in blood, chlorpyrifos had a higher mean concentration (73.33 µg/L) than terbufos. For PYRs in blood, cypermethrin and imiprothrin were the most frequently detected species with the highest mean concentrations (151.25 and 141.25 µg/L). The concentrations of PYRs appeared to be higher than that of OPs, and the most frequently detected PYRs were commonly used in domestic products, suggesting that the exposure could mostly originate from use of domestic insecticides. The correlation between insecticides in blood and their metabolites in urine was significantly high (r = 0.795 for OPs and 0.882 for PYRs, p < 0.001), indicating routine exposure at a steady state. Residents should be cautious with domestic use of insecticide products to lower their exposure.