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Variation of indoor minimum mortality temperature in different cities: Evidence of local adaptations
2019
Thai, Phong K. | Cândido, Christhina | Asumadu-Sakyi, Akwasi | Barnett, Adrian | Morawska, L. (Lidia)
Epidemiological studies on the impact of outdoor temperature to human health have demonstrated the capability of humans to adapt to local climate. However, there is limited information on the association between indoor temperature and human health, despite people spending most of their time indoors. The problem stems from the lack of sufficient indoor temperature measurement in the population. To overcome this obstacle, this paper presents an indirect epidemiological approach to evaluate the impact of high indoor temperature on mortality. The relationships between indoor-outdoor temperatures in different climate zones identified in the literature were combined with the outdoor temperature-mortality curves of the same locations to obtain the local indoor minimum mortality temperatures (iMMT), the temperature at which mortality is lowest, which by implication is the temperature at which the population is most comfortable on average. We show that the iMMT varies and has a weak linear relationship with the distance to the equator, which provides evidence of human adaptation to local indoor temperatures. These findings reinforce the adaptive comfort theory, which states that people can adapt to local indoor environment and establish their thermal comfort. Recognising the human adaptability to local climate will direct flexible and optimized policy to protect public health against extreme temperature events. This will also help reduce energy consumption for regulating indoor temperature without compromising the occupants’ health.
Show more [+] Less [-]Assessing the risk caused by ground level ozone to European forest trees: A case study in pine, beech and oak across different climate regions
2007
Emberson, L.D. | Buker, P. | Ashmore, M.R.
Two different indices have been proposed for estimation of the risk caused to forest trees across Europe by ground-level ozone, (i) the concentration based AOT40 index (Accumulated Over a Threshold of 40 ppb) and (ii) the recently developed flux based AFstY index (Accumulated stomatal Flux above a flux threshold Y). This paper compares the AOT40 and AFstY indices for three forest trees species at different locations in Europe. The AFstY index is estimated using the DO3SE (Deposition of Ozone and Stomatal Exchange) model parameterized for Scots pine (Pinus sylvestris), beech (Fagus sylvatica) and holm oak (Quercus ilex). The results show a large difference in the perceived O3 risk when using AOT40 and AFstY indices both between species and regions. The AOT40 index shows a strong north-south gradient across Europe, whereas there is little difference between regions in the modelled values of AFstY. There are significant differences in modelled AFstY between species, which are predominantly determined by differences in the timing and length of the growing season, the periods during which soil moisture deficit limits stomatal conductance, and adaptation to soil moisture stress. This emphasizes the importance of defining species-specific flux response variables to obtain a more accurate quantification of O3 risk. A new flux-based model provides a revised assessment of risks of ozone impacts to European forests.
Show more [+] Less [-]The gut retention time of microplastics in barnacle naupliar larvae from different climatic zones and marine habitats
2021
Yu, Sing-Pei | Nakaoka, Masahiro | Chan, Benny K.K.
Microplastic ingestion has been widely documented in marine zooplankton, but the retention time of microplastics in their digestive gut are still poorly studied, especially among species from different climatic zones and marine habitats. This study evaluated the ingestion and gut retention time of four sizes of fluorescent microplastic beads (1.3, 7.3, 10.6, and 19.0 μm) in stage II naupliar larvae of nine barnacle species from different habitats (epibiotic on turtles, mangroves, coral reefs, and rocky shores) and climatic zones (subtropical/tropical and temperate). Microbeads were not lethal to all species (climatic zones/habitats) tested from the four sizes of non-fluorescent virgin microbeads (1.7, 6.8, 10.4 and 19.0 μm, each at concentrations 1, 10, 100, and 1000 beads mL⁻¹). Gut retention time of microplastic beads in barnacle naupliar larvae significantly increased with decreasing size. Microbeads resided in digestive tracts generally 3–4 times longer in rocky shore and coral reef barnacles than in muddy shore and epibiotic ones. However, species from different climatic zone did not differ in retention time. Our results suggested nauplius larvae from rocky shore and coral reef barnacles appear to be more susceptible to the impacts of longer retained microplastics (e.g., toxic chemicals present on the surface).
Show more [+] Less [-]Temperature exposure during pregnancy and birth outcomes: An updated systematic review of epidemiological evidence
2017
Zhang, Yunquan | Yu, Chuanhua | Wang, Lu
Seasonal patterns of birth outcomes have been observed worldwide, and there was increasing evidence that ambient temperature played as a trigger of adverse birth outcomes, such as preterm birth (PTB), low birth weight (LBW), and stillbirth. To systematically review updated epidemiological evidence about the relationship between temperature exposure during pregnancy and PTB, LBW, and stillbirth, we searched for related studies published in English from electronic databases and references of identified papers. We only included original articles that directly reported the effects of prenatal temperature exposure on birth outcomes. The characteristics and main findings of included studies were examined. A total of 36 epidemiological studies were finally included in this review. Most of these studies focused on PTB and LBW, while less attention has been paid to stillbirth that was relatively rare in the occurrence. Several designs including ecological (e.g., descriptive and time-series) and retrospective cohort studies (e.g., case-crossover and time-to-event) were applied to assess temperature effects on birth outcomes. Temperature metrics and exposure windows varied greatly in these investigations. Exposure to high temperature was generally found to be associated with PTB, LBW, and stillbirth, while several studies also reported the adverse impact of low temperature on birth outcomes of PTB and LBW. Despite no conclusive causality demonstrated, the current evidence for adverse effect on birth outcomes was stronger for heat than for cold. In summary, the evidence linking birth outcomes with ambient temperature was still very limited. Consequently, more related studies are needed worldwide and should be conducted in diversified climate zones, so as to further ascertain the association between temperature and birth outcomes. Future studies should focus on more sophisticated study designs, more accurate estimation of temperature exposure during pregnancy, and more efficient methods to find out the exposure windows, as well as cold-related effects on birth outcomes.
Show more [+] Less [-]Urbanization intensifies tree sap flux but divergently for different tree species groups in China
2022
Ouyang, Lei | Du, Jie | Zhang, Zhenzhen | Zhao, Ping | Zhu, Liwei | Ni, Guangyan
In recent years, positive and negative effects of urbanization on forest ecosystem have been reported by many studies, while some uncertainties about the impact of urbanization-induced spatial heterogeneity of environmental factors on forest systems still remain unclear. In this study, we analyzed the urbanization effects on sap flux of a common subtropical evergreen tree species Schima superba along an urban–rural gradient in Guangdong Province, South China, and identified the consistency of these results among different groups (evergreen, deciduous, and coniferous species) using data from 83 previously published studies in China. The mean sap flux density (Fd) of S. superba in Xiaoqingshan (XQS), Heshan (HS), Dinghushan (DHS), and Shimentai (SMT), along the urban–rural gradient was 40.9 g m⁻² s⁻¹, 32.1 g m⁻² s⁻¹, 17.0 g m⁻² s⁻¹, and 17.5 g m⁻² s⁻¹, respectively, presenting a decreasing trend with the diminishing urbanization. This pattern in Fd tended to enlarge with tree size and was well confirmed by the enhanced leaf transpiration rate (by 119%) and photosynthetic rate (by 8.8%) for the S. superba in another urbanization gradient from the urban (Hangzhou, denoted as “HZ”) to rural sites (Jiande, denoted as “JD”) in Zhejiang Province, East China, which has similar climatic condition and urbanization with Guangdong Province. We attributed such positive effects to the decreased sapwood density and specific leaf area (SLA), as well as the increased Huber value (sap wood area/leaf area) and the sap wood specific hydraulic conductivity (KS). We also found that pollutant emission exerted more impact on Fd than climatic factors change, since the variation of the latter was not large enough to cause significant change of Fd under the same climatic zone. In addition, we conducted a principal component analysis (PCA) based on the published 83 studies. Results showed Fd of evergreen tree species was related positively to principle 1 and negatively to principle 2, respectively, whereas the Fd of deciduous broadleaf and coniferous tree species was positively and negatively related to both principles, respectively. This study demonstrated the potential impact of urbanization-related pollutant emission changes on water use of forest trees and the growth among different groups.
Show more [+] Less [-]Impacts of climate change on yield of cereal crops in northern climatic region of Pakistan
2021
Jan, Inayatullah | Ashfaq, Muhammad | Chandio, Abbas Ali
This study investigates the impacts of climate change on yield of selected cereal crops (wheat and maize) in the northern climatic region of Khyber Pakhtunkhwa (KP) province of Pakistan for the period 1986–2015. The first-generation unit root tests such as the Levin, Lin, and Chu (LLC), augmented Dickey-Fuller (ADF)–Fisher, and the second-generation unit root tests such as cross-sectional augmented Im-Pesaran-Shin (CIPS) and cross-sectional ADF (CADF) are used to check stationarity of the series. The cointegration among the variables is discovered via Pedroni test and Westerlund method. The long- and short-run impacts of climatic variables (average precipitation, maximum temperature, and minimum temperature) on yield of wheat and maize crops are assessed through the autoregressive distributed lag (ARDL) model. The empirical findings reveal that average precipitation has a significantly positive impact on yield of both crops in long- as well as short-run. The results further reveal that the effect of average minimum temperature on both crops is insignificant in long-run. However, the short-run effect of average minimum temperature is significantly positive on yield of maize crop but insignificant on yield of wheat crop. In long-run, an increase in average maximum temperature negatively affects crop yield. In short-run, however, it positively affects the yield of wheat and maize crops. The study recommends that increase in area under cultivation, development of advanced irrigation system, and farmers’ access to metrological information will help in lowering the drastic impacts of climate change on crop productivity.
Show more [+] Less [-]Climate Responsive Strategy Matrix for Designing Buildings in India
2021
N. Thakur, D. Parashar, C. Chidambaram and M. Dharwal
The starting point for a good design of any building project is the analysis of the macroclimate and microclimate of the building site that encompasses an understanding of temperature, radiation, wind, precipitation, topography, vegetation, ground cover, etc., which together describe the site climate. Although urban context somewhat unifies, climate and topography prevalent in India are varied and diverse. Most part of the country is hot, while some regions are dry throughout the year, some are humid and some others are composite. The building design features, therefore, need to vary with the diversity to provide comfortable environments naturally. The context and the requirements for thermal comfort provide the basis for building siting, selection of building form and envelope, fenestration design, choice of materials, and other aspects. The paper proposes and discusses the various climate-responsive design strategies that are best adapted for the different climatic zones of India and presents such design interventions and features as a comparative matrix. Such a comparative presentation is novel, convenient, easy to comprehend, and provides a useful toolkit for building designers. The climate-responsive interventions in building design proposed in this study have the potential to enhance built environments naturally, thereby mitigating the adverse environmental impact. The proposed strategies are also validated through a sample field survey responded by building professionals from various climatic zones of the country.
Show more [+] Less [-]Stormwater Quality Review to Evaluate Treatment for Drinking Water Supply via Managed Aquifer Recharge
2016
Page, D. | Vanderzalm, J. | Dillon, P. | Gonzalez, D. | Barry, K.
To date, there is no compiled information for stormwater quality data intended for drinking water supply via managed aquifer recharge (MAR) making risk assessment of these schemes difficult. This study compiles hazards relevant to water recycling via MAR and calculates the associated 95th percentile values. The 95th percentiles of iron, turbidity, colour and faecal indicators exceeded the guideline values at all sites. Likewise, measured hazards for which 95th percentile values met drinking water guidelines (other metals (e.g. zinc), salinity (electrical conductivity) and nutrients including nitrate) did so at all sites. Considering a variety of climatic zones and catchment characteristics and the temporal variations typical in urban stormwater quality, there was a remarkable similarity in the 95th percentile concentrations for a suite of water quality hazards in urban stormwater. This is important in consideration of drinking water risk assessments and determining treatment requirements for potable use.
Show more [+] Less [-]Impact of the mixture verses solo residue management and climatic conditions on soil microbial biomass carbon to nitrogen ratio: a systematic review
2021
Muhammad, Ihsan | Wang, Jun | Khan, Ahmad | Ahmad, Shakeel | Yang, Li | Iẓhār, ʻAlī | Zeeshan, Muhammad | Ullah, Saif | Shah, Fahad | ʻAlī, Shamsher | Zhou, Xun Bo
Cover crops (CCs) have been increasingly cultivated to boost soil quality, crop yield, and minimize environmental degradation compared with no cover crops (NCCs). There is no consensus of CCs under different climatic conditions on soil microbial biomass carbon (SMBC), soil microbial biomass nitrogen (SMBN), and soil microbial biomass carbon and nitrogen ratio (SMBC/SMBN) are yet documented. Thus, a global meta-analysis of 40 currently available literature was carried out to elucidate the effect of CCs on SMBC and SMBN, and its ratio for cash and cover cropping systems was conducted. Our findings demonstrated that CCs increased SMBC, SMBN, and SMBC/SMBN ratios by 39, 51, and 20%, respectively, as compared to NCCs. The categorical meta-analyzes showed that the mixture of legume and nonlegume CCs decreased the SMBC, SMBN, and SMBC/SMBN ratios relative to the sole legume or nonlegume CCs. Nonlegume CCs enhanced the SMBC, SMBN, and SMBC/SMBN ratio compared to legume CCs. When CCs residues were incorporated into the soil or surface mulched, the SMBC and SMBN increased compared to the removal of residues. The effect of CCs on the SMBN and SMBC/SMBN ratio was higher in medium-textured soils compared to coarser or fine-textured soils, but coarser-textured soils have a higher SMBC. The effect of CCs on SMBN and SMBC/SMBN ratio was prominent on medium-textured soils having soil organic carbon (SOC) in the range of 10–20 mg g⁻¹, pH > 6.5, and total nitrogen (TN) in the range of 1–2%. It was concluded that CCs enhanced SMBC, SMBN, and its ratio compared to NCCs. The response, however, varied depending on the soil properties and climatic region. Cover crops can boost the biological soil’s health by increasing the microbial population’s abundance compared to NCCs.
Show more [+] Less [-]Acidification at Plastic Lake, Ontario: Has 20 Years Made a Difference
2007
Watmough, Shaun A | Aherne, Julian | Eimers, M Catherine | Dillon, Peter J
In response to reduced sulphur emissions, there has been a large decrease in sulphate ( [graphic removed] ; -0.97 μeq l-¹ year-¹) and hydrogen (-1.18 μeq l-¹ year-¹) ion concentration in bulk precipitation between 1980 and 2000 at Plastic Lake in central Ontario. The benefit of this large reduction in [graphic removed] deposition on stream water chemistry was assessed using the gauged outflow from a conifer-forested catchment (PC1; 23.3 ha), which is influenced by a small wetland located immediately upstream of the outflow. Sulphate concentrations declined, but not significantly due to large inter-annual variation in [graphic removed] concentration. Between 1980 and 2000, there were significant increases in dissolved organic carbon, ammonium and potassium concentration likely reflecting increased mineralisation in the wetland. Calcium concentrations in PC1 decreased during the two decade period (-2.24 μeq l-¹ year-¹), as a consequence there was no improvement in stream pH and the Ca:Al ratio in PC1 continued to decline. A similar response was noted in an upland-draining sub-catchment of PC1-08 that has been monitored since 1987. Despite large reductions in [graphic removed] deposition and almost complete retention of nitrogen in soil, there has been no improvement (in terms of pH) in stream water at PC1 due to a combination of soil acidification and climatic (droughts, increased mineralisation) perturbations.
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