Air pollution is considered a key stress factor affecting the annual ring widths of the trees, especially living in industrialized areas. The SilesiaKrakow Upland is one of the most polluted areas in Poland. Scots pine stands living there have been under influence of air pollution for a long period of time. Dendrochronological analysis in five separated transects, which were performed in this region, showed the abrupt and usually long term reductions observed in radial increments of sampled pines. The abrupt increase of reductions started in the beginning of 1960s. Most of them occurred in the years , after this period the number of Scots pine trees with reduced annual increments decreased considerably. The distribution of reductions in particular sites, especially of the Olkusz transects, indicate a distinct relationship between the amount of reductions and distance from local source of pollution. On the other hand the similarity in temporal distribution of reductions in all transects indicate that the studied area was probably also under influence of air pollution of a regional type.

Air pollution emissions were not continually monitored in the Upper Silesian Industrial District (USID), southern Poland, and data is only available for the last 20 years. Long-lasting and severe tree ring reductions in pines growing 5–20 km north of the USID area recorded particularly high levels of air pollution emissions in the period 1950–1990. Especially high amounts of reductions and many missing rings were found in the period 1964–1981. At the same time, pines growing 60 km west of the USID do not record deep ring reductions; this proves that the phenomenon is of a regional nature. Increases in infant mortality and lung, bronchial, and tracheal cancer morbidity rates among males were also recorded in the USID during periods of high air pollution. Infant mortality rates increased several years after the tree ring reductions. Therefore, it may be possible to use tree ring reductions as an early indicator of the occurrence of adverse effects on human health.

No abstract

Study of soils in St. John's, Canada showed elevated Pb levels representing a potential exposure risk for young children. Old trees growing in the city present a potential annually-resolved record of Pb levels over past centuries that provides important temporal and spatial dimensions to Pb exposure risk assessment. This paper reports the results of our analytical tests to develop a fast, reliable and cost-efficient method using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) for measuring Pb concentration in annual tree rings from available tree species. Our tests focused on approaches to sample preparation as they affect the laser ablation process, the relative merits of the ablation sampling method, and the response of our available tree species, which have contrasting wood structures, to laser ablation. The range of annual Pb concentrations (ppm) measured for each of the study species were as follows: spruce (0.18-6.42); elm (0.12-7.91); and horse chestnut (0.40-14.09). Our results demonstrate that the cutting procedure for preparing tree cores produced the most consistent Pb concentrations of the three methods, although they each displayed problematic anomalies. The selection of the best laser ablation technique appears to be highly dependent on study species and goals. In general, spot analysis permits detailed and targeted studies of tree-ring structures, but requires careful sampling attention for species with complex wood anatomy. The line scan method is ideal for reconstructing annually resolved element concentrations from trees and to some degree mitigates the complicating issue of intra-ring variability. Horse chestnut was determined to be the best of the available tree species because it exhibited a good response to laser ablation and produced the lowest intra-ring variations in Pb concentration.