Bird extirpations and community dynamics in an Andean cloud forest over 100 years of land-use change

Long-term studies to understand biodiversity changes remain scarce—especially so for tropical mountains. We examined changes from 1911 to 2016 in the bird community of the cloud forest of San Antonio, a mountain ridge in the Colombian Andes. We evaluated the effects of past land-use change and assessed species vulnerability to climate disruption. Forest cover decreased from 95% to 50% by 1959, and 33 forest species were extirpated. From 1959 to 1990, forest cover remained stable, and an additional 15 species were lost—a total of 29% of the forest bird community. Thereafter, forest cover increased by 26% and 17 species recolonized the area. The main cause of extirpations was the loss of connections to adjacent forests. Of the 31 (19%) extirpated birds, 25 have ranges peripheral to San Antonio, mostly in the lowlands. Most still occurred regionally, but broken forest connections limited their recolonization. Other causes of extirpation were hunting, wildlife trade, and water diversion. Bird community changes included a shift from predominantly common species to rare species; forest generalists replaced forest specialists that require old growth, and functional groups, such as large-body frugivores and nectarivores, declined disproportionally. All water-dependent birds were extirpated. Of the remaining 122 forest species, 19 are vulnerable to climate disruption, 10 have declined in abundance, and 4 are threatened. Our results show unequivocal species losses and changes in community structure and abundance at the local scale. We found species were extirpated after habitat loss and fragmentation, but forest recovery stopped extirpations and helped species repopulate. Land-use changes increased species vulnerability to climate change, and we suggest reversing landscape transformation may restore biodiversity and improve resistance to future threats.     

Water Consumption Habit in General Population of Shanghai and Beijing, China

饮用水是人体暴露于有毒物质的重要暴露源,为了定量描述饮用水中污染物对暴露人群所造成的危害,世界各国的科学家们对饮用水的健康风险评价做了大量的研究. 通常,健康风险评价需要污染物毒理学数据和暴露人群的暴露剂量数据. 目前,针对很多的有毒污染物,国际上已经建立了应用于健康风险评价的毒理学数据库,同时积累了大量可用的有效数据. 而对于暴露人群的暴露剂量数据,则是健康风险评价所要研究的重点. 正确估计暴露人群的暴露剂量需要消费者提供大量的消费信息. 例如,暴露人群每天消费的饮用水水量. 美国环保局(EPA)认为成人每天消耗的饮用水水量为2L·d-1,此外,饮用水的消耗量会随着暴露人群的身体活动状况和所处环境状况(温度,湿度等)的改变而改变. 目前,许多研究都是关于饮用水消费信息的,总体来讲这些研究结果基本上与美国环保局所采用的饮水消耗数据相一致. 需要说明的是中国居民有完全不同于西方人的饮用水消费方式,如果在进行中国居民饮用水健康风险评价过程中应用美国环保局的假设会带来较大的不确定性. 饮用水健康风险评价工作在我国开展并不多,尤其缺少中国居民饮用水消费习惯的数据库. 这些客观条件使得在我国进行饮用水健康风险评价时只能从基础做起,积累有效的数据. 本研究以北京和上海两座城市居民为研究对象,2002年到2004年分冬夏两季分别进行了4次饮用水消费习惯调查. 研究采用随机入户方式(2004年至2005年),与中央电视台-索福瑞联合调查有限公司合作进行. 参加调查的家庭从中央电视台入户收视率调查的基础数据库中随机抽取,在抽取过程中兼顾了不同城区、年龄结构、知识结构、收入水平等因素. 研究表明,北京和上海居民冬夏两季的日均饮水量分别为2.2L·d-1、1.7L·d-1、2.0L·d-1和1.8L·d-1,这一结果和美国环保局的假设基本一致. 同时本研究考察了性别、年龄、职业和季节对应用水消费习惯的影响. 研究表明,日均饮水量随年龄的增加有增加的趋势,这一趋势在北京的夏季调查中趋势明显(p=0.01);男性的日均饮用水量大于女性,在上海冬季和夏季调查中均存在显著的差异(冬季：p=0.01;夏季：p=0.04);季节也同样影响被访者的日均饮水量,但是在4次调查中均未发现显著性差异. 在北京冬季和夏季的调查中均发现了工作地点对饮用水消费习惯的显著影响(夏季p=0.01 和冬季p=0.00). 研究同样考察了居民饮用水消费类型,调查结果表明,煮沸后的自来水是中国居民最主要的日常饮品(上海夏季：58.3%;上海冬季67.9%;北京夏季：42.7%;北京冬季：60.0%). 同时消费桶装纯净水的被访者也占有相当的比重(上海夏季：36.2%;上海冬季：24.7%;北京夏季：30.7%;北京冬季：60.0%). 研究同时表明,在中国居民的日常生活中牛奶和豆奶已经成为重要的日常饮品. 极少量的居民(北京夏季：10.7%;北京冬季5.7%;上海夏季1.2%;上海冬季0.6%)有直接饮用自来水的习惯. 研究表明滞留水(在自来水水管中滞留6h以上的自来水)是对人体健康影响最大的水,而在我们的调查中,中国居民几乎不直接饮用滞留水. 当前,饮用水健康风险评价在世界范围内蓬勃展开,但是这一技术在我国还处于起步阶段. 本研究作为饮用水健康风险评价的前期工作,为其在中国的进一步发展提供了基础性的数据.     

Geochemistry,mineralogy, solid-phase fractionation and oral bioaccessibility of lead in urban soils of Lisbon

An urban survey of Lisbon, the largest city in Portugal, was carried out to investigate its environmental burden, emphasizing metallic elements and their public health impacts. This paper examines the geochemistry of lead (Pb) and its influence on human health data. A total of 51 soil samples were collected from urban recreational areas used by children to play outdoors. The semi-quantitative analysis of Pb was carried out by inductively coupled plasma mass spectrometry after an acid digestion. X-ray diffraction was used to characterize the soil mineralogy. The solid-phase distribution of Pb in the urban soils was investigated on a subset of 7 soils, out of a total of 51 samples, using a non-specific sequential extraction method coupled with chemometric analysis. Oral bioaccessibility measurements were obtained using the Unified BARGE Method developed by the Bioaccessibility Research Group of Europe. The objectives of the study are as follows: (1) investigation of Pb solid-phase distribution; (2) interpretation of Pb oral bioaccessibility measurements; (3) integration of metal geochemistry with human health data; and (4) understanding the influence of geochemistry and mineralogy on oral bioaccessibility. The results show that the bioaccessible fraction of Pb is lower when major metal fractions are associated with less soluble soil phases such as Fe oxyhydroxides, and more increased when the metal is in the highly soluble carbonate phase. However, there is some evidence that the proportion of carbonates in the soil environment is also a key control over the oral bioaccessibility of Pb, irrespective of its solid-phase fractionation.     

Lethal effects of abamectin on the aquatic organisms Daphnia similis, Chironomus xanthus and Danio rerio

Abamectin is used as an acaricide and insecticide for fruits, vegetables and ornamental plants, as well as a parasiticide for animals. One of the major problems of applying pesticides to crops is the likelihood of contaminating aquatic ecosystems by drift or runoff. Therefore, toxicity tests in the laboratory are important tools to predict the effects of chemical substances in aquatic ecosystems. The aim of this study was to assess the potential hazards of abamectin to the freshwater biota and consequently the possible losses of ecological services in contaminated water bodies. For this purpose, we identified the toxicity of abamectin on daphnids, insects and fish. Abamectin was highly toxic, with an EC₅₀ 48 h for Daphnia similis of 5.1 ng L⁻¹, LC₅₀ 96 h for Chironomus xanthus of 2.67 μg L⁻¹ and LC₅₀ 48 h for Danio rerio of 33 μg L⁻¹.     

Basic oxygen furnace sludge to treat industrial arsenic- and sulfate-rich acid mine drainage

Environmental Science and Pollution Research - In this study, four systems (S1, S2, S3, and S4) were evaluated to determine whether basic oxygen furnace sludge (BOFS), mainly composed of Fe (84%,...     

Abundance,distribution, and characteristics of microplastics in coastal surface waters of the Colombian Caribbean and Pacific

Environmental Science and Pollution Research - Microplastic pollution has become a global concern due to its distribution, high abundance, and negative impacts on aquatic ecosystems. These...     

Genotoxicity,oxidative stress,and inflammatory response induced by crack-cocaine: relevance to carcinogenesis

Environmental Science and Pollution Research - Crack-cocaine is a cocaine by-product widely consumed by general population in developing countries. The drug is low cost and is associated with more...     

Validation of spectral gas radiation models under oxyfuel conditions—Part B: Natural gas flame experiments

Combustion of hydrocarbon fuels with pure oxygen results in a different flue gas composition as combustion with air. Standard CFD spectral gas radiation models for air blown combustion are out of their validity range. The series of three articles provides a common spectral basis for the validation of new developed models. Part B of the series presents spectral measurements in the spectral range of 2.4–5.4 μm of a 70 kW turbulent natural gas flame in air blown combustion and in wet and dry oxyfuel combustion. The experimentally measured intensity spectra were compared with simulated spectra based on measured gas atmospheres. The line-by-line database HITEMP2010 and the two statistical-narrow-band models EM2C and RADCAL were used for the numerical simulation. The measured spectra showed large fluctuations due to turbulence. The up to 75% increased averaged experimental intensity compared to the simulated intensity pointed out the importance of the effect of turbulence-radiation-interaction in combustion simulations.     

Evaluation of optimal conditions for determination of low selenium content in shellfish samples collected at Todos os Santos Bay,Bahia, Brazil using HG-AFS

This work proposes a procedure for the determination of total selenium content in shellfish after digestion of samples in block using cold finger system and detection using atomic fluorescent spectrometry coupled hydride generation (HG AFS). The optimal conditions for HG such as effect and volume of prereduction KBr 10 % (m/v) (1.0 and 2.0 ml) and concentration of hydrochloric acid (3.0 and 6.0 mol L^?1) were evaluated. The best results were obtained using 3 mL of HCl (6 mol L^?1) and 1 mL of KBr 10 % (m/v), followed by 30 min of prereduction for the volume of 1 mL of the digested sample. The precision and accuracy were assessed by the analysis of the Certified Reference Material NIST 1566b. Under the optimized conditions, the detection and quantification limits were 6.06 and 21.21 μg kg^?1, respectively. The developed method was applied to samples of shellfish (oysters, clams, and mussels) collected at Todos os Santos Bay, Bahia, Brazil. Selenium concentrations ranged from 0.23?±?0.02 to 3.70?±?0.27 mg kg^?1 for Mytella guyanensis and Anomalocardia brasiliana, respectively. The developed method proved to be accurate, precise, cheap, fast, and could be used for monitoring Se in shellfish samples.     

TPS/PCL Composite Reinforced with Treated Sisal Fibers: Property, Biodegradation and Water-Absorption

Sisal fibers bleached with sodium-hydroxide followed by hydrogen peroxide treatment were incorporated in a thermoplastic starch/ε-polycaprolactone (TPS/PCL) blend via extrusion processing. These samples with smooth and homogenous surfaces were examined for their property, biodegradability and water absorption. Scanning electron microscopy revealed that the fibers were well dispersed in the matrix. In addition, it was found that the fibers and matrices interacted strongly. Blends with 20 % (dry weight-basis) fiber content showed some fiber agglomeration. Whereas blends with 10 % fibers showed increased crystallinity and lower water absorption capacity. The CO₂ evolution study showed that the thermoplastic starch samples without any additives had the highest rate and extent of degradation whereas the neat PCL samples had the lowest degradation rate. Addition of fiber to the TPS/PCL blend exhibited the degradation rates and extents that were somewhere in between the pure TPS and neat PCL. This work demonstrates that TPS/PCL composites reinforced with bleached sisal has superior structural characteristics and water resistance and thus, can be used as polymeric engineering composites for different applications.