Assessment of workers’ exposure to Aflatoxin B1 in a Portuguese waste industry

Aflatoxin B1 (AFB1) is considered by different International Agencies as a genotoxic and potent hepatocarcinogen. However, despite the fact that the fungi producing this compound are detected in some work environments, AFB1 is rarely monitored in occupational settings. The aim of the present investigation was to assess exposure to AFB1 of workers from one Portuguese waste company located in the outskirt of Lisbon. Occupational exposure assessment to AFB1 was done with a biomarker of internal dose that measures AFB1 in the serum by enzyme-linked immunosorbent assay. Forty-one workers from the waste company were enrolled in this study (26 from sorting; 9 from composting; 6 from incineration). A control group (n = 30) was also considered in order to know the AFB1 background levels for the Portuguese population. All the workers showed detectable levels of AFB1 with values ranging from 2.5ng ml−1 to 25.9ng ml−1 with a median value of 9.9±5.4ng ml−1. All of the controls showed values below the method’s detection limit. Results obtained showed much higher (8-fold higher) values when compared with other Portuguese settings already studied, such as poultry and swine production. Besides this mycotoxin, other mycotoxins are probably present in this occupational setting and this aspect should be taken into consideration for the risk assessment process due to possible synergistic reactions. The data obtained suggests that exposure to AFB1 occurs in a waste management setting and claims attention for the need of appliance of preventive and protective safety measures.

Moisture recycling in the Iberian Peninsula from a regional climate simulation: spatiotemporal analysis and impact on the precipitation regime

The contribution of the evapotranspiration from a certain region to the precipitation over the same area is referred to as water recycling. In this paper, we explore the spatiotemporal links between the recycling mechanism and the Iberian rainfall regime. We use a 9 km resolution Weather Research and Forecasting simulation of 18 years (1990-2007) to compute local and regional recycling ratios over Iberia, at the monthly scale, through both an analytical and a numerical recycling model. In contrast to coastal areas, the interior of Iberia experiences a relative maximum of precipitation in spring, suggesting a prominent role of land-atmosphere interactions on the inland precipitation regime during this period of the year. Local recycling ratios are the highest in spring and early summer, coinciding with those areas where this spring peak of rainfall represents the absolute maximum in the annual cycle. This confirms that recycling processes are crucial to explain the Iberian spring precipitation, particularly over the eastern and northeastern sectors. Average monthly recycling values range from 0.04 in December to 0.14 in June according to the numerical model and from 0.03 in December to 0.07 in May according to the analytical procedure. Our analysis shows that the highest values of recycling are limited by the coexistence of two necessary mechanisms: (1) the availability of sufficient soil moisture and (2) the occurrence of appropriate synoptic configurations favoring the development of convective regimes. The analyzed surplus of rainfall in spring has a critical impact on agriculture over large semiarid regions of the interior of Iberia.

Evaluation of lung function abnormalities prevalence in poultry workers

Introduction - Poultry workers can be at an increased risk of occupational respiratory diseases, like asthma, chronic obstructive pulmonary disease and extrinsic allergic alveolitis. Spirometry screening is fundamental to early diagnosis trough the identification of related ventilatory defects. Purpose - We aimed to assess the prevalence of lung function abnormalities in poultry workers.

Mechanical performance of concrete made with aggregates from construction and demolition waste recycling plants

This research aims at analysing the mechanical performance of concrete with recycled aggregates (RA) from construction and demolition waste (CDW) from various locations in Portugal. First the characteristics of the various aggregates (natural and recycled) used in the production of concrete were thoroughly analysed. The composition of the RA was determined and several physical and chemical tests of the aggregates were performed. In order to evaluate the mechanical performance of concrete, compressive strength (in cubes and cylinders), splitting tensile strength, modulus of elasticity and abrasion resistance tests were performed. Concrete mixes with RA from CDW from several recycling plants were evaluated, in order to understand the influence that the RA's collection point, and consequently their composition, has on the characteristics of the mixes produced. The analysis of the mechanical performance allowed concluding that the use of RA worsens most of the properties tested, especially when fine RA are used. On the other hand, there was an increase in abrasion resistance when coarse RA were used. In global terms, the use of this type of aggregates, in limited contents, is viable from a mechanical viewpoint. (C) 2015 Elsevier Ltd. All rights reserved.

Performance of concrete made with recycled aggregates from Portuguese CDW recycling plants

The objective of this research is the production of concrete with recycled aggregates (RA) from various CDW plants around Portugal. The influence of the RA collection location and consequently of their composition on the characteristics of the concrete produced was analysed. In the mixes produced in this research RA from five plants (Valnor, Vimajas, Ambilei, Europontal and Retria) were used: in three of them coarse and fine RA were analysed and in the remaining ones only coarse RA were used. The experimental campaign comprised two tests in fresh concrete (cone of Abrams slump and density) and eight in hardened concrete (compressive strength in cubes and cylinders, splitting tensile strength, modulus of elasticity, water absorption by immersion and capillarity, carbonation and chloride penetration resistance). It was found that the use of RA causes a quality decrease in concrete. However, there was a wide results scatter according to the plant where the RAs were collected, because of the variation in composition of the RA. It was also found that the use of fine RA causes a more significant performance loss of the concrete properties analysed than the use of coarse RA. © (2015) Trans Tech Publications, Switzerland.