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ObjectiveTo explore the effect of exposure to atmospheric particulate matters on the outpatient visits of respiratory disorders in Jiaxing City，Zhejiang Province. MethodsDaily air pollutant monitoring data，meteorological data and outpatient visits of respiratory disorders in Jiaxing City from 2019 to 2021 were collected．A generalized additive model was applied to evaluate the effect and laggeel effect of the concentrations of atmospheric particulates for outpatient visits of respiratory disorders after adjusting for secular trend， day-of-the-week effect， holiday effect， and meteorological variables. ResultsThe daily average concentrations of PM2.5， PM10， O3 and NO2 exceeded the standard， and the proportion of days exceeding the standard was 3.4%， 1.3%， 11.0% and 0.8%， respectively. Every 10 μg·m-3 increase in PM2.5 concentration showed the strongest effects on the daily outpatient visits of respiratory disorders， adult and childhood respiratory disorders all on lag07 with ER（95%CI） being 2.29%（1.35%‒3.24%）， 2.31% （1.39%‒3.23%） and 2.65 % （1.36%‒3.96%）， respectively. The maximum ER of outpatient visits for respiratory disorders in children was higher than that in adults. Every 10 μg·m-3 increase in PM10 concentration showed the strongest effects on the daily outpatient visits of respiratory disorders on lag07， adult respiratory disorders on lag06 and childhood respiratory disorders on lag07 with ER（95%CI） being 1.42% （0.87%‒1.96%）， 1.49%（0.99%‒1.99%） and 1.61% （0.87%‒2.36%）， respectively. The results of double-pollutant model showed that the effect of atmospheric particulate reduced after O3 was introduced into the model. ConclusionThere are a short-term effect and a laggeel effect of atmospheric particulate on the outpatient visits of respiratory disorders. It is necessary to strengthen the health protection of the respiratory system of the population， especially the children.
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Objective To observe the deposition of PM2.5 in the contact lens and its influence on the oxygen permeability and refractive index of the contact lens.Methods Atmospheric PM2.5 was collected for preparation of 1 mg · mL-1 PM2.5 suspension.Then,18 rigid gas permeable contact lenses (RGPCL) and 18 soft contact lens lenses (SCL) were grouped in control,experimental and PBS-rinse group,with 6 RGPCL and 6 SCL in each group.RGPCL and SCL in the experimental and PBS-rinse groups were incubated in 1 mg · mL-1 PM2.5 solution for 24 h,followed by PBS-rinse group were further washed for 1 h in PBS,whereas the controls were incubated in PBS for 24 h.All of them were examined with field scanning electron microscopy.Meanwhile,oxygen permeability and refractive index of contact lens were measured using the polar graphic devices and refractometry respectively.All the obtained data were quantitatively and statistically analyzed.Results After treatment in PM2.5 solution,there was a large amount of PM2.5 deposition on the RGPCL surface in the experimental group,and the amount of PM2.5 was counted (3.19 ± 1.64) · 100 μm-2,while no atmospheric particulate matter was found in the control group;following the treatment of PBS,a lot of PM2.5 attached on the surface of RGPCL remained visible,and the number of particles was (5.12 ± 1.27) · 100 μm-2.And the difference was statistically significant between the control group and PBS-rinse group (P ＜0.05).In addition,and the amount of PM2.5 attached on the surface of SCL in the exPerimental group was (2.16 ± 1.19) · 100 μm-2,while there wasn t any atmospheric particulate matter in the control group;and,after a wash of SCL in PBS,the amount of PM2.5 on SCL surface was (0.56 ±0.39) · 100 μm-2 in the PBS-rinse group,indicating a statistically difference between the control group and PBS-rinse group (P ＜0.05).Moreover,the amount of PM2.5 attachment on SCL surface in the experimental group was significantly lower than that of the control group,and the difference was statistically significant (P ＜ 0.05).After PM2.5 solution treatment,oxygen permeability of RGPCL and SCL was 100.00 ± 3.17 and 42.00 ± 2.57 respectively in the experimental group,as well as 100.00 ±2.36 and 41.00 ± 3.44 in the control group,with no statistically significant difference between the two groups (all P ＞ 0.05);while refractive index of RGPCL and SCL was 1.415 6 ±0.000 4 and 1.3737 ±0.000 7 respectively in the experimental group,as well as 1.415 3 ±0.000 4 and 1.373 7 ±0.000 l in the control group,with no statistically significant difference between the two groups either (all P ＞ 0.05).Conclusion PM2.5 can be attached to the surface of RGPCL and SCL,and PM2.5 is easier to adhere to RGPCL surface and is not easy to elute when compared with SCL,but PM2.5 deposition do not affect oxygen permeability and refractive index of contact lenses over a short span of time.
ABSTRACT
Lots of evidence show a correlation between air pollution and chronic respiratory diseases, of which the effect of particulate matter is the most concerned.It is the current research hotspot that respiratory diseases in both children and adults are closely related with atmospheric pollution levels.The influence mechanisms of atmos-pheric pollution on respiratory diseases include oxidative stress, inflammation, genetic damage, etc.This paper made a review of the latest advances s on the pathogenesis of chronic respiratory diseases caused by atmospheric particulates PM2.5 .
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A thermal desorption ( TD) device was developed and coupled to gas chromatography ( GC) or gas chromatography-mass spectrometry ( GC-MS ) for the qualitative and quantitative analysis of semi-volatile organic compounds on atmospheric particulate matters ( PM ) . The TD was operated by direct heating and placed on the GC injector, leading to high heating rate and easy transfer of analytes to GC without focusing of analytes by cold trap. For establishing the TD-GC method, the materials used for supporting PM samples, temperature and time of thermal desorption, and types of sample injection were investigated for detection of sixteen polycyclic aromatic hydrocarbons ( PAHs) and nine n-alkanes. The limits of detection of the proposed TD-GC method were in the range of 0. 014-0. 093 ng for PAHs, and 0. 016-0. 026 ng for n-alkanes, respectively, with the correlation coefficients of correlation above 0. 9975. The TD-GC method was applied to the determination of trace PAHs and n-alkanes on PM10 samples from three cities. The recoveries were in the range of 95%-135% ( PAHs) and 95%-115% ( n-alkanes) , respectively. Finally, the TD was coupled to GC-MS for comparison of the contents of PAHs and n-alkanes on PMx with different particulate size ( x=10 , 5, 2, 1, 0. 5, 0. 25, 0. 1).