(1) Background: This study investigated the relationship between weather conditions, diurnal patterns, and total knee range of motion (ROM), as well as the severity of symptoms (pain and stiffness) in older adults with knee osteoarthritis. (2) Methods: An exploratory longitudinal study was conducted on 28 older adults with knee osteoarthritis (mean age 71.86 ± 4.49 years; 46.4% men, 53.6% women). We used as assessment tools the Visual Analog Scales (VAS) for self-reported local knee pain and stiffness, and goniometry for ROM. Measurements were taken twice, six months apart, in winter and summer, in the morning and evening of each selected day. Recorded weather factors comprised temperature, relative humidity, barometric pressure, and maximum wind speed. (3) Results: The study revealed significant effects of season and time of day on pain and stiffness, respectively (p < 0.001). Additionally, a significant interaction between season and time influenced total knee ROM (p < 0.001). Moreover, there was a statistically significant relationship between time and total knee ROM (p < 0.001). (4) Conclusions: This research underscores the complex link between seasonal fluctuations and daily variations in some symptomatic and functional aspects of knee osteoarthritis in older adults.

Based on online monitoring data of air quality and meteorological parameters, the long-term variations, spatial differences, and meteorological influencing factors of ground-level ozone (O3) pollution in Zhengzhou were studied. In addition, the transport pathways and potential source regions of O3 were investigated. The results show that surface O3 concentrations at the city station in Zhengzhou City increased significantly during the period 2014-2018 (P<0.05) with a growth rate of 15.50 μg·(m3·a)-1, and the timespan of exceeding pollutant standards was extended. The monthly O3 variations showed an \"M\" pattern with the seasonal maximum in summer. The diurnal O3 variations showed a \"single-peak\" pattern with a diurnal concentrations peak at 15:00-16:00, while the diurnal peak at the rural station was relatively high (130.94 μg·m-3). At the urban station, the exceedance probability of O3 concentrations was relative high when hourly temperature (T) exceeded 23℃, relative humidity (RH) was less than 65%, wind speed (WS) ranged 2.0-4.0 m·s-1, and wind direction was southeast or northeast. Based on the multivariate linear fitting of impact factors on O3, the main controlling factors at the city and industrial sites were also identified as T and RH compared to T and WS at the traffic and suburb sites. Back trajectory analysis and potential sources of O3 during different seasons were significantly different, with the dominant transport trajectories during spring and summer being short-distance and slow-moving airflows from the south and northeast; autumn and winter were characterized by long-distance and quick-moving airflows from the northwest. The high O3 concentrations observed in summer were mainly affected by local photochemical formation and regional transport from Hebei, Shandong, and Anhui Provinces.

Assessing the transport of natural radionuclides in the atmosphere provides a powerful tool to study air mass circulation. Here, we investigated the seasonal atmospheric distribution of the naturally produced 7Be in surface air over Europe between 40° N and 68° N during the period 1975-2018. The results suggest that the inter-annual variability of 7Be reflects production rates of the radionuclide induced by solar modulation of cosmic rays. Further analysis of the meteorological influences indicates that the meteorological influences on 7Be concentrations are geographically and seasonally dependent. We found that, in general, the tropopause pressure plays an important factor influencing 7Be activity for winter and spring seasons while the sea level pressure and temperature are more dominant during summer and autumn seasons. The combination of tropospheric production rates and meteorological parameters explains 24%-79% variances of the seasonal 7Be activity. We further applied a three-box model to study the influence of stratosphere-troposphere exchanges on 7Be concentrations. The simulation supports that the seasonal cycle of 7Be in Europe is controlled by two main factors: the changing height of the troposphere (seasonality of the tropopause height) and seasonal variations of the stratosphere-troposphere exchanges.

In this study, we conducted an observation experiment from May 1 to June 30, 2018 in Zhengzhou, a major city in central China, where ground ozone (O3) pollution has become serious in recent years. The concentrations of O3 and its precursors, as well as H2O2 and meteorological data were obtained from the urban site (Yanchang, YC), suburban (Zhengzhou University, ZZU) and background sites (Ganglishuiku, GLSK). Result showed that the rates of O3 concentration exceeded Chinese National Air Quality Standard Grade II (93.3 ppbv) were 59.0%, 52.5%, and 55.7% at the above three sites with good consistency, respectively, indicating that O3 pollution is a regional problem in Zhengzhou. The daily peak O3 appeared at 15:00-16:00, which was opposite to VOCs, NOx, and CO and consistent with H2O2. The exhaustive statistical analysis of meteorological factors and chemical effects on O3 formation at YC was advanced. The high concentration of precursors, high temperature, low relative humidity, and moderately high wind speed together with the wind direction dominated by south and southeast wind contribute to urban O3 episodes in Zhengzhou. O3 formation analysis showed that reactive alkenes such as isoprene and cis-2-butene contributed most to O3 formation. The VOCs/NOx ratio and smog production model were used to determine O3-VOC-NOx sensitivity. The O3 formation in Zhengzhou during early summer was mainly under VOC-limited and transition regions alternately, which implies that the simultaneous emission reduction of alkenes and NOx is effective in reducing O3 pollution in Zhengzhou.

Black carbon (BC), produced from the incomplete combustion of carbonaceous fuels, has emerged as a major contributor to global climate change with adverse health effects. Based on one-year (2016.06.01-2017.06.30) equivalent black carbon (eBC) measurements, this study analyzed the characteristics of eBC concentrations and the local-regional contributions at an urban site (Pudong, PD) and a suburban site (Qingpu, QP) in Shanghai, China. The results showed that the annual average eBC concentrations were 1.17 ± 0.61 μg m-3 and 2.09 ± 0.97 μg m-3 at PD and QP, respectively. The high eBC concentrations occurred in winter and at weekends both for PD and QP. There were significant negative correlation coefficients between the daily eBC, the daily wind speed (WS) and the daily boundary layer height (BLH) at PD (rws: 0.45, rblh = -0.35, p < 0.01) and QP (rws: 0.49, rblh = -0.32, p < 0.01). And the relative higher eBC concentrations coincided with southerly, southwesterly and westerly winds although these winds had lower frequencies. This could be related to the agricultural fire in these directions during summer harvesttime. The significant partial correlation coefficients of eBC-CO (ru:0.37-0.64, rs:0.18-0.44, p < 0.01) and eBC-NO2 (ru:0.49-0.74, rs:0.38-0.75, p < 0.01) could suggest that eBC mainly come from vehicular exhaust emissions in Shanghai. Besides, the higher eBC/PM2.5 (5.29% ± 1.94%) and eBC/CO(0.30% ± 0.14%) at QP indicated the more combustion activities and diesel-powered vehicle emissions in suburban areas. The concentration weighted trajectory (CWT) analysis indicated that the surrounding areas at the junction of Shanghai, Jiangsu, and Zhejiang provinces seemed to be relatively the most important sources outside of Shanghai.

Recently, ground ozone has become one major airborne pollutant and the frequency of ozone-induced pollution episodes has increased rapidly across China. However, due to the lack of long-term observation data, relevant research on the characteristics and influencing factors of urban ozone concentrations remains limited. Based on ground ozone observation data during 2006-2016, we quantified the causality influence of individual meteorological factors on ozone concentrations in Beijing using a convergent cross mapping (CCM) method. The result indicated that the influence of each meteorological factor on ozone concentrations varied significantly across seasons and years. At the inter-annual scale, all-year meteorological influences on ozone concentrations were much more stable than seasonal meteorological influences. At the seasonal scale, meteorological influences on ozone concentrations were stronger in spring and autumn. Amongst multiple individual factors, temperature was the key meteorological influencing factor for ozone concentrations in all seasons except winter, when wind, humidity and SSD exerted major influences on ozone concentrations. In addition to temperature, air pressure was another meteorological factor that exerted strong influences on ozone concentrations. At both the inter-annual and seasonal scale, the influence of temperature and humidity on ozone concentrations was generally stable whilst that of other factors experienced large variations. Different from PM2.5, meteorological influences on ozone concentrations were relatively weak in summer, when ozone concentrations were the highest in Beijing. Given the generally stable meteorological influences on ozone concentrations and human-induced emissions of VOCs and NOx across seasons, warming induced notable increase in summertime biogenic emissions of VOCs and NOx can be a major driver for the increasing ozone pollution episodes. This research provides useful references for understanding long-term meteorological influences on ozone concentrations in mega cities in China.

High concentrations of ozone in urban and industrial regions worldwide have long been a major air quality issue. With the rapid increase in fossil fuel consumption in China over the past three decades, the emission of chemical precursors to ozone-nitrogen oxides and volatile organic compounds-has increased sharply, surpassing that of North America and Europe and raising concerns about worsening ozone pollution in China. Historically, research and control have prioritized acid rain, particulate matter, and more recently fine particulate matter (PM2.5). In contrast, less is known about ozone pollution, partly due to a lack of monitoring of atmospheric ozone and its precursors until recently. This review summarizes the main findings from published papers on the characteristics and sources and processes of ozone and ozone precursors in the boundary layer of urban and rural areas of China, including concentration levels, seasonal variation, meteorology conducive to photochemistry and pollution transport, key production and loss processes, ozone dependence on nitrogen oxides and volatile organic compounds, and the effects of ozone on crops and human health. Ozone concentrations exceeding the ambient air quality standard by 100-200% have been observed in China\'s major urban centers such as Jing-Jin-Ji, the Yangtze River delta, and the Pearl River delta, and limited studies suggest harmful effect of ozone on human health and agricultural corps; key chemical precursors and meteorological conditions conductive to ozone pollution have been investigated, and inter-city/region transport of ozone is significant. Several recommendations are given for future research and policy development on ground-level ozone.