Relevant Aspects on Biomonitoring of Heavy Metal Concentration in Environmental Air in Asunción City

Abstract

Introduction: Briophytes (mosses) have long been used to determine the concentration of heavy metals as an alternative to the collection of atmospheric aerosols. We elaborated the present study to evaluate the environmental concentration of lead, cadmium, mercury and arsenic in autochthonous species of moss exposed during a period to urban environment and to analyze some methodological aspects of biomonitoring in Paraguay. Material and methods: In an observational study moss samples were obtained from Cerro Patiño (34.4km from Asuncion) to be transplanted in 5 sites of high vehicular traffic in the city of Asunción. One of the samples was taken as control (Moss control 1). The samples were left outdoors for 58 days (2 September 2013 - 29 October 2013) and then collected and subjected to study using the Inductive Coupling Plasma Source Mass Spectrometry technique. The bryophytes were characterized and recorded all the climatological variables that occurred during the study period. A second sampling phase of control moss was required (Moss control 2). Results: After 58 days of exposure, lead and arsenic levels were detected. The bryophytes used belonged to two families: hypnaceae and pilotrichaceae. The range of temperature, relative humidity, wind and precipitation did not reach extreme levels during the cycle studied. Discussion: Discrete levels of lead and arsenic are detected in the samples studied here and could represent the studied areas, although other research on variation within and between the moss species of our country is necessary.

Keywords

• bryophyta
• lead
• arsenic
• environmental monitoring
• mass spectrometry