There are limited economic and reliable tools to monitor the effects of airborne particulate matter PM originating from rapid industrialization, urbanization, population growth, and economic development. It is now well established that urban PM contains magnetic particles along with other air pollutants. The velocity and temporal variability of the deposition of such PM on tree leaves are subject to the pollution sources, climate, and local atmospheric conditions. Therefore, these variables have to be taken into account during a biomonitoring. This study presents a magnetic biomonitoring in the city of Querétaro. In the city's metropolitan area, the most abundant and perennial tree species for biomonitoring is Ficus benjamina. For leaves of this species, the number of days needed for collection NDNC was measured, taking into account the meteorological conditions and the time at which they reached the saturation of airborne PM (pollutants). By means of sequential sampling, we identified that the minimum NDNC after a rainfall > 3 mm is 15 days. In such a period, total suspended particle TSP depositions reach its dynamic equilibrium. This behavior can be observed from measurements of specific magnetic susceptibility χ in Ficus benjamina samples and their comparison with TSP depositions collected with traditional Hi-Vol monitoring systems. After the NDNC calculation, a magnetic monitoring was performed with the biomonitor Ficus benjamina to evaluate the air quality at different sites in the metropolitan area every month for a period of 5 months. Values of χ ranged from 0.45 to 18.52 × 10-8m3kg-1. The species Ficus benjamina can be used as a biomonitor in the city of Querétaro only in seasons (winter-spring) with no or low rainfall. The species has the advantage of providing current PM information about a specific period of time.
Keywords: Air pollution; Biomonitor; Magnetic susceptibility; PM; Rate leaf deposition.
Assessment of atmospheric metal pollution in the urban area of Mexico City, using Ficus benjamina as biomonitor.Bull Environ Contam Toxicol. 2011 May;86(5):495-500. doi: 10.1007/s00128-011-0252-9. Epub 2011 Mar 25. Bull Environ Contam Toxicol. 2011. PMID: 21437785
Biomonitoring of atmospheric particulate pollution via chemical composition and magnetic properties of roadside tree leaves.Environ Sci Pollut Res Int. 2018 Sep;25(26):25994-26004. doi: 10.1007/s11356-018-2592-z. Epub 2018 Jul 2. Environ Sci Pollut Res Int. 2018. PMID: 29968213
Assessing atmospheric particulate matter distribution based on Saturation Isothermal Remanent Magnetization of herbaceous and tree leaves in a tropical urban environment.Sci Total Environ. 2014 Feb 1;470-471:975-82. doi: 10.1016/j.scitotenv.2013.10.082. Epub 2013 Nov 13. Sci Total Environ. 2014. PMID: 24239818
Framework for using deciduous tree leaves as biomonitors for intraurban particulate air pollution in exposure assessment.Environ Monit Assess. 2016 Aug;188(8):479. doi: 10.1007/s10661-016-5482-1. Epub 2016 Jul 23. Environ Monit Assess. 2016. PMID: 27450373 Review.
Impacts of particulate matter pollution on plants: Implications for environmental biomonitoring.Ecotoxicol Environ Saf. 2016 Jul;129:120-36. doi: 10.1016/j.ecoenv.2016.03.012. Epub 2016 Mar 22. Ecotoxicol Environ Saf. 2016. PMID: 27011112 Review.