Instituto de Biociências, Universidade de São Paulo, São Paulo, Brazil; Instituto de Estudos Avançados, Universidade de São Paulo, São Paulo, Brazil.
Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brazil.
Environ Pollut. 2020 Aug;263(Pt A):114583. doi: 10.1016/j.envpol.2020.114583. Epub 2020 Apr 16.
Although air pollution decreased in some cities that shifted from an industrial to a service-based economy, and vehicular emission regulation became more restrictive, it is still a major risk factor for mortality worldwide. In central São Paulo, Brazil, air quality monitoring stations and tree-ring analyses revealed a decreasing trend in the concentrations of particulate matter and metals. Such trends, however, may not be observed in industrial districts located in the urban periphery, where the usual mobile sources may be combined with local stationary sources. To evaluate environmental pollution in an industrial district in southeastern São Paulo, we assessed its spatial variability, by measuring magnetic properties and concentrations of Al, Ba, Ca, Cl, Cu, Fe, K, Mg, Mn, P, S, Sr, Zn in the bark of 62 trees, and its temporal trends, by measuring Cd, Cu, Ni, Pb, V, Zn in tree rings of three trees. Source apportionment analysis based on tree barks revealed two clusters with high concentrations of metals, one related to vehicular and industrial emissions (Al, Ba, Cu, Fe, Zn) in the east side of the industrial cluster, and the other related to soil resuspension (Cu, Zn, Mn) in its west side. These patterns are also supported by the magnetic properties of bark associated with iron oxides and titanium-iron alloy concentrations. Dendrochemical analyses revealed that only the concentrations of Pb consistently decreased over the last four decades. The concentrations of Cd, Cu, Ni, V, and Zn did not significantly decrease over time, in contrast with their negative trends previously reported in central São Paulo. This combined biomonitoring approach revealed spatial clusters of metal concentration in the vicinity of this industrial cluster and showed that the local population has not benefited from the decreasing polluting metal concentrations in the last decades.
尽管一些从工业经济向服务型经济转型的城市的空气污染有所减少，车辆排放法规也变得更加严格，但空气污染仍是全球范围内导致死亡的主要危险因素之一。在巴西圣保罗市中心，空气质量监测站和树木年轮分析显示，颗粒物和金属的浓度呈下降趋势。然而，这种趋势可能不会出现在位于城市边缘的工业区，在那里，常见的移动污染源可能与当地固定污染源相结合。为了评估东南部圣保罗工业区的环境污染，我们通过测量 62 棵树的树皮中的磁性和 Al、Ba、Ca、Cl、Cu、Fe、K、Mg、Mn、P、S、Sr、Zn 的浓度，评估了其空间变异性，并通过测量三棵树的年轮中的 Cd、Cu、Ni、Pb、V、Zn，评估了其时间趋势。基于树木树皮的源分配分析揭示了两个金属浓度高的聚类，一个与工业区东侧的车辆和工业排放有关（Al、Ba、Cu、Fe、Zn），另一个与西侧土壤再悬浮有关（Cu、Zn、Mn）。这些模式也得到了与氧化铁和钛铁合金浓度相关的树皮磁性特征的支持。树木化学分析显示，只有 Pb 的浓度在过去四十年中持续下降。Cd、Cu、Ni、V 和 Zn 的浓度并没有随着时间的推移而显著下降，与之前在圣保罗中心报道的负趋势形成对比。这种综合生物监测方法揭示了该工业区附近金属浓度的空间聚类，并表明当地居民并未从过去几十年中污染金属浓度的下降中受益。
