Admir Créso Targino

Use of passive samplers to detect organochlorine pesticides in air and water at wetland mountain region sites (S-SE Brazil)

Low-density polyethylene (LDPE) passive samplers were deployed in upland surface waters and the overlying atmosphere during May and June 2012, to determine the transport and trends of freely dissolved and gaseous organochlorine pesticides (OCPs) along altitudinal gradients in mountain regions in south and southeast Brazil. Gaseous OCP concentrations were dominated by hexachlorobenzene (3.0-29 pg m(-3)) and endosulfans (Ʃ = α-endosulfan + β-endosulfan + endosulfan sulphate, 170-260 pg m(-3)), whereas freely dissolved endosulfans were significantly higher than all other OCPs (p < 0.001). The presence of some target pesticides at the highest elevation sites indicated their efficient high-altitude transport from regional sources. Air-water exchange gradients indicated net deposition of most volatile and recently banned OCPs (e.g., HCB, endosulfan) over Brazilian mountains. Moreover, the exposure of these sites to large-scale continental airflows with varying source contributions may partly explain the atmospheric deposition of selected OCPs over upland freshwaters at tropical and subtropical mountains sites in Brazil. These findings, coupled with LDPE passive air and water sampling measurements, point out the potential inputs from distant sources of semi-volatile chemicals to the two high-altitude sites.

Utilização de sensoriamento remoto em análises de albedo e temperatura de superfície em Londrina - PR: contribuições para estudos de ilha de calor urbana

This study retrieved surface albedo (αs ) and land surface temperature Tsur using remote sensing data in order to provide information for studies of Urban Heat Island (UHI) in the city of Londrina (Parana). We have used αs and Tsur data from the MODIS sensor, and in situ measurements of near-surface air temperature (Tair) acquired between June and August 2011 at 13 sites across the city area. The albedo and surface temperature data were used to calculate an urbanization index (UI), and further compared with Tair. In general, the data analysis of αs and Tsur was consistent with the in situ measurements, showing its applicability in the assessment of the spatial-temporal features of UHI. The urban area of Londrina showed UI values between 18 and 20, whilst vegetated areas had values between 14 and 16. The values are consistent with other studies, representing a useful methodology to assess the spatial-temporal evolution of urban areas. The index can also provide detailed information to assess the impact of land cover change on local and regional climate. Moreover, the results indicate that satellite data can greatly assist in the quantification of UHI when in situ air temperature data are unavailable.