[Impact of Emission Reduction in Different Sectors on Air Quality and Atmospheric Temperature in Eastern China]

China's emission reduction policy will focus on the synergistic control of air pollution and atmospheric warming in future. However, the impacts of emission reductions in different sectors on air quality and atmospheric temperature vary significantly. Using a two-way coupled air quality model(WRF-Chem), this study quantified the impacts of anthropogenic emission reductions from various sectors(industrial, residential, transportation, thermal power plants, and agricultural sectors) on air quality and atmospheric temperature in eastern China in September 2016. Emission reduction from industrial, residential, transportation, thermal power plant, and agricultural sources could effectively improve air quality, with PM2.5 reduction of 33.9%, 9.6%, 15.8%, 10.8%, and 26.7%, respectively; however, the weakened aerosol-radiation interactions resulted in more energy at the surface, further increasing the near-surface air temperature by 0.04, 0.03, 0.01, 0.03, and 0.09℃. At the top of the atmosphere, the net radiation flux decreased by 0.3, 0.8, 0.7, and 0.1 W·m-2 owing to the emission reduction from industrial, residential, traffic, and thermal power plant sectors, whereas the emission reduction from agricultural sources resulted in an increase in the net radiation flux of 0.8 W·m-2. On one hand, the emission reduction from agricultural sources led to a decrease in scattering aerosols and increase in the net radiation flux; contrastingly, it did not lead to a decrease in absorbing aerosols(black carbon), which could not offset the radiation increase caused by the decrease in scattering aerosols. Therefore, the emission reduction from agricultural sources led to the increase in net radiation flux at the top of the atmosphere and the most significant increase in near-surface temperature. It is noted that in the future, although emission reduction from agricultural sources will bring about significant air quality improvement, it will also consequently cause significant warming.

[Spatiotemporal Variations in Atmospheric Urban Heat Island Effects and Their Driving Factors in 84 Major Chinese Cities]

Accelerating urbanization seriously intensifies urban heat island effects in China, which in turn affects regional environment and human health. However, the spatiotemporal patterns of atmospheric urban heat island effects remain poorly understood in China as previous research is mostly based on satellite-sensed radiation temperatures. Using long-term daily meteorological observations from 1960 to 2017, this study explored the geographical distribution of atmospheric urban heat islands over diurnal, intra-annual, and inter-annual timescales in 84 major cities in China. The results show that on average, the intensity of the urban heat island reaches(0.9±1.1)℃, although large geographical variations were detected. The intensity was, overall, larger in northern China than in southern China; North China showed the largest annual intensity of(1.4±1.4)℃, and seasonal intensity variations were high in northeast and northwest China. Here, significantly higher intensity effects were measured at night[(1.2±1.1)℃] than during the day[(0.5±1.2)℃], and in summer than winter during the day, and in winter than summer during the night. Inter-annually, the annual mean urban heat island effect has increased by an average of 0.040℃ per decade, although this trend weakens after 2009. Furthermore, we found that the spatial patterns of atmospheric heat island intensity was greatly affected by climatic background conditions and the location of meteorological stations, while the long-term trends were strongly influenced by the impervious surface area. This study improves understanding of the atmospheric urban heat island effect in China and provides important insights for formulating urban land-use strategies to alleviate high temperatures and heatwaves.

Comparison of Temperature Readings, Infrared, Non-Contact Thermometer with Contact Digital Thermometer Readings in Children

BACKGROUND

Body temperature is an important vital sign in clinical practice which can be measured via electronic contact thermometers and infrared non-contact thermometers.

OBJECTIVE

To compare temperature readings taken by non contact infrared thermometer with the conventional digital axillary, rectal and oral temperature readings as well as the influence of environmental temperature on noncontact infrared thermometer readings.

METHODOLOGY

A prospective study carried out in the Paediatric outpatient clinic of the Rivers State University Teaching Hospital, Nigeria from September 2020 to December 2020. Infrared noncontact forehead and jugular temperatures along with contact axillary, oral and rectal temperatures at a recorded atmospheric temperature and pressure were measured. Data collected was analysed.

RESULTS

A total of 247 children aged 1month to 16 years were enrolled, the mean differences of the temperature pairs of contact and non-contact thermometry ranged from 0.45 - 0.77°C (1.64, -1.81°C) 95% LoA. The highest mean difference was found between infrared forehead and axillary [MD; 0.45(1.64,-0.73°C) 95%LoA] temperatures. There was a significant positive correlation between the mean difference of infrared forehead/ rectal temperature and atmospheric temperature (r = 0 .211 p = 0.029). Linear regression model showed that infrared forehead temperature of 37.1°C was equivalent to rectal temperature of 38°C and axillary of 37.4°C which is the standard cut off for fever. Infrared jugular of 37.2°C was equivalent to rectal of 38°C and axillary temperature of 37.4°C was equivalent to infrared jugular of 37.03°C all at a mean atmospheric temperature of 28.3±1.8°C.

CONCLUSION

The mean difference by which infrared noncontact thermometry predicts core temperatures may differ based on atmospheric temperature. Infrared non-contact forehead thermometer reading of 37.1°C could be considered as the fever cut off for non-contact forehead thermometry in Nigeria in regions where the mean atmospheric temperature is 28.3±1.8°C.

A simple experiment on global warming

A simple experiment has been developed to demonstrate the global warming potential of carbon dioxide (CO2) gas in the Earth's atmosphere. A miniature electric resistance heating element was placed inside an inflatable balloon. The balloon was filled with either air or CO2. Whereas the CO2 partial pressure on the earth's atmosphere is approximately 4 × 10-4 atm, in this experiment, a high partial pressure of CO2 (1 atm) was used to compensate for the short radiation absorption path in the balloon. The element was heated to approximately 50°C, the power was then switched off and the element's cooling trends in air and in CO2 were monitored. It took a longer time to cool the heating element back to ambient temperature in CO2 than in air. It also took longer times to cool the element in larger size balloons and in pressurized balloons when they were filled with CO2. To the contrary, the balloon size or pressure made no difference when the balloons were filled with air. A simple mathematical model was developed, and it confirmed that the radiative heat loss from the element decreased significantly in CO2. This investigation showed that the cooling rate of an object, with surface temperature akin to temperatures found on Earth, is reduced in a CO2-rich atmosphere because of the concomitant lower heat loss to its environment.

Habitat Preferences and Trophic Position of Brachydiplax chalybea flavovittata Ris, 1911 (Insecta: Odonata) Larvae in Youngsan River Wetlands of South Korea

In freshwater ecosystems, habitat heterogeneity supports high invertebrate density and diversity, and it contributes to the introduction and settlement of non-native species. In the present study, we identified the habitat preferences and trophic level of Brachydiplax chalybea flavovittata larvae, which were distributed in four of the 17 wetlands we examined in the Yeongsan River basin, South Korea. Larval density varied across four microhabitat types: open water area, and microhabitats dominated by Myriophyllum aquaticum, Paspalum distichum, and Zizania latifolia. Microhabitats dominated by M. aquaticum had the highest larval density, followed by those dominated by P. distichum. The larvae were more prevalent in silt sediments than in plant debris or sand. Stable isotope analysis showed that B. chalybea flavovittata is likely to consume, as a food source, other species of Odonata larvae. We conclude that successful settlement of B. chalybea flavovittata can be attributed to their habitat preferences. As temperature increases due to climate change, the likelihood of B. chalybea flavovittata spreading throughout South Korea increases. We, therefore, recommend continued monitoring of the spread and ecological impacts of B. chalybea flavovittata.

A Case-Crossover Study to Investigate the Effects of Atmospheric Particulate Matter Concentrations, Season, and Air Temperature on Accident and Emergency Presentations for Cardiovascular Events in Northern Italy

Atmospheric particulate matter (PM) has multiple adverse effects on human health, high temperatures are also associated with adverse health outcomes, and the frequency of cardiovascular events (CVEs) varies with season. We investigated a hypothesized increase in PM-related accident and emergency (A&E) presentations for CVE with high temperature, warm season, days of high influenza incidence, and in people with a cancer diagnosis, using a time-stratified case-crossover study design. Outcomes were associations of A&E presentation for CVE with atmospheric PM ≤ 10 μm (PM₁₀), season, and air temperature. PM₁₀ levels in the municipality of residence (exposure variable) were estimated by modeling data from local monitoring stations. Conditional logistic regression models estimated odds ratios (OR) with 95% confidence intervals (CI) for presentations in relation to supposed influencers, adjusting for confounders. Study participants were all who presented at the A&E of a large hospital near Milan, Italy, for a CVE (ICD-9: 390–459) from 1st January 2014 to 31st December 2015. There were 1349 A&E presentations for CVE in 2014–2015 and 5390 control days. Risk of A&E presentation was significantly increased on hot days with OR 1.34 (95%CI 1.05–1.71) per 10 μg/m³ PM₁₀ increment (as mean PM₁₀ on day of presentation, and 1 and 2 days before (lags 0–2)), and (for lag 0) in autumn (OR 1.23, 95%CI 1.09–1.37) and winter (OR 1.18, 95%CI 1.01–1.38). Risks were also significantly increased when PM₁₀ was on lag 1, in people with a cancer diagnosis in the spring and summer months (1.88, 95%CI 1.05–3.37), and on days (lags 0–2) of high influenza incidence (OR 2.34, 95%CI 1.01–5.43). PM₁₀ levels exceeded the 50 μg/m³ “safe” threshold recommended by the WHO and Italian legislation for only 3.8% of days during the warm periods of 2014–2015. Greater risk of A&E presentation for CVE in periods of high PM₁₀ and high temperature suggests that “safe” thresholds for PM₁₀ should be temperature-dependent and that the adverse effects of PM₁₀ will increase as temperatures increase due to climate change.