Camila Elias

Seleção de epífitas acumuladoras de elementos químicos na Mata Atlântica

Epiphytes are efficient indicators of atmospheric pollution because of their direct uptake of chemical elements from atmosphere. Leaves from eleven species of bromeliads and one species of orchid were collected in the Parque Estadual Carlos Botelho, SP, for determination of sixteen chemical elements. The selection of the best biomonitor species was based on the diversity and accumulation of chemical elements in the leaves. With an average accumulation index of 0.7, Canistropsis billbergioides has potential to be used as a biomonitor of chemical elements in the Atlantic Forest.

Neutron activation analysis for assessing chemical composition of dry dog foods

Brazil holds the second largest population of domestic dogs in the world, with 33 million dogs, only behind the United States. The annual consumption of dog food in the country is 1.75 million tons, corresponding to the World’s sixth in trade turnover. Dog food is supposed to be a complete and balanced diet, formulated with high quality ingredients. All nutrients and minerals required for an adequate nutrition of dogs are added to the formulation to ensure longevity and welfare. In this context, the present study aimed at assessing the chemical composition of dry dog foods commercialized in Brazil. Thirty-four samples were acquired in the local market of Piracicaba and analyzed by instrumental neutron activation analysis (INAA) to determine the elements As, Br, Ca, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Se, U, and Zn. In general, the concentrations of Ca, Fe, K, Na, and Zn complied with the values required by the Association of American Feed Control Officials (AAFCO). To evaluate the safety of dog food commercialized in Brazil, further investigation is necessary to better understand the presence of toxic elements found in this study, i.e. Sb and U. INAA was useful for the screening analysis of different types and brands of dry dog foods for the determination of both essential and toxic elements.

Survey of lanthanoids in plants from a tropical region

Several anthropogenic sources may provide lanthanoids (La, Ce, Nd, Sm, Eu, Tb and Yb) to the agricultural and forestry landscapes. Because little information is available on the distribution of these chemical elements in Brazilian tropical ecosystems, this work focuses on the survey in leaves of diverse plant species (native trees, epiphytes and crops) from different ecosystems. Soil under crown projection was also analysed, thereby estimating the influence of its chemical composition on accumulation in leaves. The degree of lanthanoids accumulation varied substantially even for species growing in the same habitat. The most accumulator species, Alsophila sternbergii, presented the typical distribution pattern for lanthanoids, different from Pachystroma longifolium, a native species from the urban fragment, and the cultivated Citrus sp., in which the altered patterns revealed lanthanum enrichment in spite of cerium depletion in the leaves.

Atmospheric chemical element pollution in an urban water-associated environment

Nowadays, sustainability has become a complicated issue mainly in urban centres. Owing to the atmospheric emissions, the incorporation of toxic chemical elements is still not well known for urban water-associated ecosystems. Tillandsia bromeliads were employed as passive biomonitors of air pollution. Otherwise, the tank bromeliad Canistropsis billbergioides, native to the Atlantic Forest, was employed for assessing pollution levels since the tank, unlike atmospheric epiphytes, also accumulates chemical elements from water and litterfall. The present study aimed at using leaves of the native epiphytic bromeliads (passive biomonitoring) from riparian areas and the species C. billbergioides (active) to evaluate the atmospheric input of chemical elements for wet ecosystems from the Piracicaba City, Sao Paulo State, Brazil. Chemical elements determined by Instrumental Neutron Activation Analysis (INAA), such as As, Cr, Hg, Ni, Sb and Zn, were accumulated in leaves of bromeliads. By combining passive and active experimental designs, hotspots for chemical atmospheric pollution were identified in the Piracicaba River Basin.

Sustainable sampling of native bromeliads for environmental monitoring

By analysing the leaves of bromeliads, the availability of chemical elements in the atmosphere can be assessed. However, sampling steps affect the reliability of using such plants for environmental quality studies. This paper describes a novel and sustainable sampling methodology for conservation units, in which small discs (6 mm diameter) of bromeliad leaves could be taken without removing rosettes. Bromeliad leaf discs were sampled from the top, middle and bottom positions of the rosettes. For comparison, the whole rosettes were also analysed by the k0 method and Instrumental Neutron Activation Analysis (INAA). Considering the 11 bromeliad species evaluated, the results of sustainable sampling compared with usual sampling (after milling and sub-sampling) did not demonstrate significant differences at the 95% confidence level for Br, Cs, K, Na, Rb, Sc and Zn. Consequently, sustainable sampling was considered to be reliable at the current level of studies for environmental quality assessment.