Intentional homicide, drug trafficking and social indicators in Salvador, Bahia, Brazil. / Homicídios dolosos, tráfico de drogas e indicadores sociais em Salvador, Bahia, Brasil.

To study the association between intentional homicide, drug trafficking and social indicators in Salvador, Bahia, Brazil in 2010. This is an ecological study, based on cases of intentional homicides and drug trafficking registered by the Civil Police of Bahia, as well as social indicators. A negative binomial regression model, utilizing R software (version 2.13.0), was used to verify the association between the homicide rate, drug trafficking and the proportion of black males aged 15 - 49. There were 1391 homicides in 2010, giving a rate of 108.5 homicides per 100,000 people. It was observed that in neighborhoods with a proportion of black males aged 15 - 49 over 60%, this rate increased by 89% (≥ 60% and ≤ 80%) and 87% (> 80%), compared to neighborhoods with less than 60% of black males aged 15 - 49. Regarding the factor of drug trafficking, there was a statistically significant average increase of 40% in terms of this coefficient in neighborhoods with five or more cases of drug trafficking, compared to neighborhoods with less than five of such cases. The empirical evidence that was observed can help to contribute to the existing knowledge about the phenomenon of deaths due to homicide in large cities, and it will also help managers, public security and organized civil society to face this problem.

O objetivo deste artigo é verificar a associação entre homicídio doloso, tráfico de drogas e indicadores sociais em Salvador, Bahia, Brasil, no ano de 2010. Trata-se de estudo ecológico a partir dos casos de homicídios dolosos e de tráfico de drogas registrados pela Polícia Civil da Bahia com indicadores sociais. A análise entre o coeficiente de homicídio doloso, tráfico de drogas e proporção de homens negros de 15 a 49 anos foi feita através do modelo de regressão binomial negativa, com software R versão 2.13.0. Foram registrados 1.391 homicídios dolosos em 2010, gerando coeficiente de 108,5 homicídios por 100mil habitantes. Na associação foi observado que nos bairros com proporção de homens negros de 15 a 49 anos acima de 60%, esse coeficiente aumentou 89% (≥ 60% e ≤ 80%) e 87% (> 80%), comparado com bairros com proporção menor que 60%. Quanto ao tráfico de drogas, houve aumento médio de 40% estatisticamente significante nesse coeficiente nos bairros com 5 ou mais casos, comparado com bairros com menos de 5. As evidências empíricas observadas poderão contribuir para o conhecimento sobre o fenômeno dos óbitos por homicídios dolosos nas grandes cidades e poderá auxiliar gestores, segurança pública e sociedade civil organizada no enfrentamento desse problema.

Homicídios dolosos, tráfico de drogas e indicadores sociais em Salvador, Bahia, Brasil / Intentional homicide, drug trafficking and social indicators in Salvador, Bahia, Brazil

Resumo O objetivo deste artigo é verificar a associação entre homicídio doloso, tráfico de drogas e indicadores sociais em Salvador, Bahia, Brasil, no ano de 2010. Trata-se de estudo ecológico a partir dos casos de homicídios dolosos e de tráfico de drogas registrados pela Polícia Civil da Bahia com indicadores sociais. A análise entre o coeficiente de homicídio doloso, tráfico de drogas e proporção de homens negros de 15 a 49 anos foi feita através do modelo de regressão binomial negativa, com software R versão 2.13.0. Foram registrados 1.391 homicídios dolosos em 2010, gerando coeficiente de 108,5 homicídios por 100mil habitantes. Na associação foi observado que nos bairros com proporção de homens negros de 15 a 49 anos acima de 60%, esse coeficiente aumentou 89% (≥ 60% e ≤ 80%) e 87% (> 80%), comparado com bairros com proporção menor que 60%. Quanto ao tráfico de drogas, houve aumento médio de 40% estatisticamente significante nesse coeficiente nos bairros com 5 ou mais casos, comparado com bairros com menos de 5. As evidências empíricas observadas poderão contribuir para o conhecimento sobre o fenômeno dos óbitos por homicídios dolosos nas grandes cidades e poderá auxiliar gestores, segurança pública e sociedade civil organizada no enfrentamento desse problema.

Abstract To study the association between intentional homicide, drug trafficking and social indicators in Salvador, Bahia, Brazil in 2010. This is an ecological study, based on cases of intentional homicides and drug trafficking registered by the Civil Police of Bahia, as well as social indicators. A negative binomial regression model, utilizing R software (version 2.13.0), was used to verify the association between the homicide rate, drug trafficking and the proportion of black males aged 15 - 49. There were 1391 homicides in 2010, giving a rate of 108.5 homicides per 100,000 people. It was observed that in neighborhoods with a proportion of black males aged 15 - 49 over 60%, this rate increased by 89% (≥ 60% and ≤ 80%) and 87% (> 80%), compared to neighborhoods with less than 60% of black males aged 15 - 49. Regarding the factor of drug trafficking, there was a statistically significant average increase of 40% in terms of this coefficient in neighborhoods with five or more cases of drug trafficking, compared to neighborhoods with less than five of such cases. The empirical evidence that was observed can help to contribute to the existing knowledge about the phenomenon of deaths due to homicide in large cities, and it will also help managers, public security and organized civil society to face this problem.

Metal accumulation in soils derived from volcano-sedimentary rocks, Rio Itapicuru Greenstone Belt, northeastern Brazil.

Many countries and some Brazilian regions have defined the guideline values for metals in soils. However, the local geological features may be so heterogeneous that global or even regional guideline values cannot be applied. The Greenstone Belts are worldwide geological formations of vast extension, containing mineralization of various metals (e.g., Au, Cr, Ni, and Ag). Natural concentrations of soils must be known to correctly assess the impact of mining. We studied the soils of the Rio Itapicuru Greenstone Belt (RIGB), of Paleoproterozoic age, sampling at 24 sites (0-0.20m) in the areas not or minimally human impacted, equally distributed in the three units of the RIGB: Volcanic Mafic Unit (VMU), Volcanic Felsic Unit (VFU), and Volcano-clastic Sedimentary Unit (SU). The natural pseudo-total concentrations of Cr, Ni, Cu, Zn, Pb, Fe, and Mn were obtained by acid digestion (EPA3050b) both in the soil and the particle-size fractions (sand and clay+silt). The concentrations of metals in RIGB soils, especially Cr and Ni, are generally higher than those reported for other regions of Brazil or other countries. Even the sedimentary soils have relatively high metal values, naturally contaminated by the VMU of the RIGB; a potential impact on Mesozoic and Cenozoic sedimentary rocks located near the study region is highly expected. Metals are concentrated (80%) in the fine particle-size fraction, implying an easy availability through surface transport (wind and runoff). We introduced a new index, called the Fe-independent accumulation factor - AF-Fe, which reveals that 90-98% of the dynamics of the trace metals is associated with the iron geochemical cycle. We primarily conclude that determining the guideline values for different soil classes in variable geological/geochemical environment and under semiarid climate is meaningless: the concentration of metals in soils is clearly more related to the source material than to the pedogenesis processes.