SEGH Articles

Spatial distribution of Pb, Cd and Cr concentrations in moss transplants from urban recreational areas in Lisbon, Portugal

03 December 2012
Metal concentrations in moss were used to assess the contribution of atmospheric pollution to the geochemistry of soil and ground-level dust, and discriminate urban pollution sources.

Sofia Bartolomeu is currently a final year Master student in Meteorology and Oceanography Physics at University of Aveiro, Portugal. She was a Poster Winner at the 9th ISEG meeting in Aveiro, Portugal in July. She is currently working on the “Geochemical survey of Lisbon urban soils” project at the Geosciences Department of the University of Aveiro, supervised by Dr. Paula Marinho. The main aim of her study was to report on spatial patterns for some metal concentrations in moss transplants that were exposed to the urban ambient air in public recreational areas in Lisbon. Metal concentrations in the moss were used to assess the contribution of atmospheric pollution to the geochemistry of soil and ground-level dust, and discriminate urban pollution sources.

Owing to their ability to accumulate heavy metals, mosses are especially suitable to monitor heavy metal airborne pollution. Heavy metals are taken up very fast due to the lack of an epidermis and a cuticle, and they have a large surface-to-weight ratio.

This study presents results from a project entitled “Geochemical survey of Lisbon urban soils: a baseline for future human health studies”, and the main aims are (1) to report on spatial patterns for Pb, Cd and Cr concentrations in moss transplants from public recreational areas in Lisbon; (2) to compare such patterns with those of soil and ground-level dust. Fifty one topsoil and ground-level dust samples were collected in playgrounds, schoolyards, urban parks, public gardens, road-side and airport of Lisbon. At each site, 1 uncontaminated moss transplant was fixed to a horizontal tree limb, which remained in situ for a period of 6 months. Only 44 moss samples were recovered from site. The selected moss species was the Hypnum cupressiforme Hedw and the green part was used for analysis of Pb, Cd and Cr by ICP-MS.


For Pb, the results show that concentrations are high, range from 7.2-75.1 mg kg-1 and the higher values occur in the older part of the city. Lead emissions are mainly related to traffic and the physiographic characteristics of the old city explain the higher Pb concentrations in the moss. The element has a similar spatial distribution in soils and dusts, suggesting that airborne Pb-particles settle in the topsoil. For Cd, the results show that concentrations are low, range from 0.08-0.44 mg kg-1 and the spatial distribution is irregular, indicating point sources. However, the airport moss samples have the highest Cd concentrations. Also soil and dust samples form the airport have the highest Cd concentrations, which suggest that air-traffic is a source of Cd in the city. For Cr, the results show that concentrations range from 1.6-8.9 mg kg-1 and the higher values occur in the old city. Soils and dust show different distribution patterns, perhaps due to the fact that in the city Cr has an important geogenic source. 

In conclusion and despite the fact that by its location on the Atlantic coast and winds regime, high levels of pollutants are uncommon in Lisbon, the biomonitoring survey indicates that Pb emissions are probably traffic related, are still significant and have an higher environmental impact in the old city where the housing density is higher, the streets are narrow and have strong slopes, and the traffic is quite intense. Concentrations of Cd and Cr are quite lower and metal-laden airborne particles do not seem to be a significant source to the urban soils.


Sofia Bartolomeu

Physics Department, University of Aveiro, Campus de Santiago, 3810-193, Aveiro, Portugal, 1.

Keep up to date

SEGH Events

Submit Content

Members can keep in touch with their colleagues through short news and events articles of interest to the SEGH community.

Science in the News

Latest on-line papers from the SEGH journal: Environmental Geochemistry and Health

  • Characteristics of PM 2.5 , CO 2 and particle-number concentration in mass transit railway carriages in Hong Kong 2017-08-01


    Fine particulate matter (PM2.5) levels, carbon dioxide (CO2) levels and particle-number concentrations (PNC) were monitored in train carriages on seven routes of the mass transit railway in Hong Kong between March and May 2014, using real-time monitoring instruments. The 8-h average PM2.5 levels in carriages on the seven routes ranged from 24.1 to 49.8 µg/m3, higher than levels in Finland and similar to those in New York, and in most cases exceeding the standard set by the World Health Organisation (25 µg/m3). The CO2 concentration ranged from 714 to 1801 ppm on four of the routes, generally exceeding indoor air quality guidelines (1000 ppm over 8 h) and reaching levels as high as those in Beijing. PNC ranged from 1506 to 11,570 particles/cm3, lower than readings in Sydney and higher than readings in Taipei. Correlation analysis indicated that the number of passengers in a given carriage did not affect the PM2.5 concentration or PNC in the carriage. However, a significant positive correlation (p < 0.001, R 2 = 0.834) was observed between passenger numbers and CO2 levels, with each passenger contributing approximately 7.7–9.8 ppm of CO2. The real-time measurements of PM2.5 and PNC varied considerably, rising when carriage doors opened on arrival at a station and when passengers inside the carriage were more active. This suggests that air pollutants outside the train and passenger movements may contribute to PM2.5 levels and PNC. Assessment of the risk associated with PM2.5 exposure revealed that children are most severely affected by PM2.5 pollution, followed in order by juveniles, adults and the elderly. In addition, females were found to be more vulnerable to PM2.5 pollution than males (p < 0.001), and different subway lines were associated with different levels of risk.

  • Comparison of chemical compositions in air particulate matter during summer and winter in Beijing, China 2017-08-01


    The development of industry in Beijing, the capital of China, particularly in last decades, has caused severe environmental pollution including particulate matter (PM), dust–haze, and photochemical smog, which has already caused considerable harm to local ecological environment. Thus, in this study, air particle samples were continuously collected in August and December, 2014. And elements (Si, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Mo, Cd, Ba, Pb and Ti) and ions ( \({\text{NO}}_{3}^{-}\) , \({\text{SO}}_{4}^{2-}\) , F, Cl, Na+, K+, Mg2+, Ca2+ and \({\text{NH}}_{4}^{+}\) ) were analyzed by inductively coupled plasma mass spectrometer and ion chromatography. According to seasonal changes, discuss the various pollution situations in order to find possible particulate matter sources and then propose appropriate control strategies to local government. The results indicated serious PM and metallic pollution in some sampling days, especially in December. Chemical Mass Balance model revealed central heating activities, road dust and vehicles contribute as main sources, account for 5.84–32.05 % differently to the summer and winter air pollution in 2014.

  • Annual ambient atmospheric mercury speciation measurement from Longjing, a rural site in Taiwan 2017-08-01


    The main purpose of this study was to monitor ambient air particulates and mercury species [RGM, Hg(p), GEM and total mercury] concentrations and dry depositions over rural area at Longjing in central Taiwan during October 2014 to September 2015. In addition, passive air sampler and knife-edge surrogate surface samplers were used to collect the ambient air mercury species concentrations and dry depositions, respectively, in this study. Moreover, direct mercury analyzer was directly used to detect the mercury Hg(p) and RGM concentrations. The result indicated that: (1) The average highest RGM, Hg(p), GEM and total mercury concentrations, and dry depositions were observed in January, prevailing dust storm occurred in winter season was the possible major reason responsible for the above findings. (2) The highest average RGM, Hg(p), GEM and total mercury concentrations, dry depositions and velocities were occurred in winter. This is because that China is the largest atmospheric mercury (Hg) emitter in the world. Its Hg emissions and environmental impacts need to be evaluated. (3) The results indicated that the total mercury ratios of Kaohsiung to that of this study were 5.61. This is because that Kaohsiung has the largest industry density (~60 %) in Taiwan. (4) the USA showed average lower mercury species concentrations when compared to those of the other world countries. The average ratios of China/USA values were 89, 76 and 160 for total mercury, RGM and Hg(p), respectively, during the years of 2000–2012.