Recycled household ceramic waste in eco-efficient cement: a case study

The ceramic wastes can cause strong damage to the environment. In this article, the experimental study was concentrated on the pozzolanic activity of household ceramic waste and clay bricks waste. The possibility of the partial replacement of Portland cement blended with ceramic waste powder without further heating treatment in different ratios was analyzed. The ceramic waste powder was mixed in samples in various ratios. The evaluation of the ceramic waste powder was performed by grain-size analyses using Laser granulometry, XRD, XRF, Frattini test and strength activity index (SAI) method. The results indicate that the pozzolanic activity of household ceramic waste was higher than that of clay bricks waste. The 15% of HC powder addition could be a possible upper bound for an effective substitution and may also be very cost-efficient for industrial application.The authors acknowledge the National Natural Science Foundation of China: Grant 51578109, and Fundação para a Ciência e a Tecnologia (SFRH/BPD/22680/2005)

Risk factors for asthma and allergy associated with urban migration: background and methodology of a cross-sectional study in Afro-Ecuadorian school children in Northeastern Ecuador (Esmeraldas-SCAALA Study)

BACKGROUND: Asthma and allergic diseases are becoming increasingly frequent in children in urban centres of Latin America although the prevalence of allergic disease is still low in rural areas. Understanding better why the prevalence of asthma is greater in urban migrant populations and the role of risk factors such as life style and environmental exposures, may be key to understand what is behind this trend. METHODS/DESIGN: The Esmeraldas-SCAALA (Social Changes, Asthma and Allergy in Latin America) study consists of cross-sectional and nested case-control studies of school children in rural and urban areas of Esmeraldas Province in Ecuador. The cross-sectional study will investigate risk factors for atopy and allergic disease in rural and migrant urban Afro-Ecuadorian school children and the nested case-control study will examine environmental, biologic and social risk factors for asthma among asthma cases and non-asthmatic controls from the cross-sectional study. Data will be collected through standardised questionnaires, skin prick testing to relevant aeroallergen extracts, stool examinations for parasites, blood sampling (for measurement of IgE, interleukins and other immunological parameters), anthropometric measurements for assessment of nutritional status, exercise testing for assessment of exercise-induced bronchospasm and dust sampling for measurement of household endotoxin and allergen levels. DISCUSSION: The information will be used to identify the factors associated with an increased risk of asthma and allergies in migrant and urbanizing populations, to improve the understanding of the causes of the increase in asthma prevalence and to identify potentially modifiable factors to inform the design of prevention programmes to reduce the risk of allergy in urban populations in Latin America