SARS-CoV-2: a systematic review of indoor air sampling for virus detection

Environmental Science and Pollution Research - In a post-pandemic scenario, indoor air monitoring may be required seeking to safeguard public health, and therefore well-defined methods, protocols,...     

Mechanisms contributing to the thermal analysis of waste incineration bottom ash and quantification of different carbon species

The focus of this study was to identify the main compounds affecting the weight changes of bottom ash (BA) in conventional loss on ignition (LOI) tests and to obtain a better understanding of the individual processes in heterogeneous (waste) materials such as BA. Evaluations were performed on BA samples from a refuse derived fuel incineration (RDF-I) plant and a hospital waste incineration (HW-I) plant using thermogravimetric analysis and subsequent mass spectrometry (TG–MS) analysis of the gaseous thermal decomposition products. Results of TG–MS analysis on RDF-I BA indicated that the LOI measured at 550 °C was due to moisture evaporation and dehydration of Ca(OH)₂ and hydrocalumite. Results for the HW-I BA showed that LOI at 550 °C was predominantly related to the elemental carbon (EC) content of the sample. Decomposition of CaCO₃ around 700 °C was identified in both materials. In addition, we have identified reaction mechanisms that underestimate the EC and overestimate the CaCO₃ contents of the HW-I BA during TG–MS analyses. These types of artefacts are expected to occur also when conventional LOI methods are adopted, in particular for materials that contain CaO/Ca(OH)₂ in combination with EC and/or organic carbon, such as e.g. municipal solid waste incineration (MSWI) bottom and fly ashes. We suggest that the same mechanisms that we have found (i.e. in situ carbonation) can also occur during combustion of the waste in the incinerator (between 450 and 650 °C) demonstrating that the presence of carbonate in bottom ash is not necessarily indicative for weathering. These results may also give direction to further optimization of waste incineration technologies with regard to stimulating in situ carbonation during incineration and subsequent potential improvement of the leaching behavior of bottom ash.     

Rural Income and Forest Reliance in Highland Guatemala

This paper estimates rural household-level forest reliance in the western highlands of Guatemala using quantitative methods. Data were generated by the way of an in-depth household income survey, repeated quarterly between November 2005 and November 2006, in 11 villages (n = 149 randomly selected households). The main sources of income proved to be small-scale agriculture (53 % of total household income), wages (19 %) and environmental resources (14 %). The latter came primarily from forests (11 % on average). In the poorest quintile the forest income share was as high as 28 %. All households harvest and consume environmental products. In absolute terms, environmental income in the top quintile was 24 times higher than in the lowest. Timber and poles, seeds, firewood and leaf litter were the most important forest products. Households can be described as ‘regular subsistence users’: the share of subsistence income is high, with correspondingly weak integration into regional markets. Agricultural systems furthermore use important inputs from surrounding forests, although forests and agricultural uses compete in household specialization strategies. We find the main household determinants of forest income to be household size, education and asset values, as well as closeness to markets and agricultural productivity. Understanding these common but spatially differentiated patterns of environmental reliance may inform policies aimed at improving livelihoods and conserving forests.     

DDT and DDE concentrations in the blood of Mexican children residing in the southeastern region of Mexico

The aim of this study was to assess the levels of dichlorodiphenyltrichloroethane (DDT) and dichlorodiphenyldichloroethylene (DDE) in the blood of children living in the southeastern region of Mexico. In this study, we found high levels of DDT and its principal metabolite (DDE) in the blood of children residing in the communities studied. The levels of total DDT found in our study ranged from 4,676.4 ng/g lipid to 64,245.2 ng/g lipid. All of the children in the study had detectable levels of DDT and/or DDE. In conclusion, our data indicate that children living within the study areas are exposed to high levels of DDT and DDE. Moreover, these results can be used as a trigger to revisit local policies on environmental exposures.