Assessment of heavy metals in propolis and soil from the Pelagonia region, Republic of Macedonia

Abstract

In this study, the contents of five representative heavy metals (Cr, Pb, Zn, Cd and Cu) were determined in soil and propolis samples from four locations in southwestern Macedonia using atomic absorption spectrometry. The aim was to pinpoint the key factors that influence the content of heavy metals in propolis and to establish whether there is a connection between the contents of heavy metals in soil and in propolis from the same location. Generally, at all of the locations, the relative concentrations of heavy metals in soil were found to decrease in the following order: Zn>Cr>Cu>Pb>Cd. The highest mean values for concentrations of heavy metals in these soils were found to be: 72. 03, 38.28, 26.64, 17.15 and 0.60 mg kg -1 for Zn, Cr, Cu, Pb and Cd, respectively, and they are all below the target values from the new Dutch list. The general trend of the heavy metal contents in propolis from the same four locations, in decreasing order, is: Pb>Cr>Zn>Cu≈Cd. Generally, the propolis samples from the highland locations (Orle and Rapeš) had lower overall contents of heavy metals than the lowland locations (Novaci and Makovo). All of the analyzed propolis samples meet the requirements of the Macedonian legislation and the international organizations for the maximum allowed levels for heavy metals. Attempts were made to find a correlation between the heavy metal contents in soil and propolis. According to our aim, the investigation presented herein offers one step towards a complete picture of ecological safety of the specific areas in the Republic of Macedonia. To do so, it is necessary to perform additional studies and to find appropriate biomonitoring methods. Further studies are needed to complete the picture and to determine the major pathways of incorporation of heavy metals in beehive products.Key words: heavy metals; soil; propolis; atomic absorption spectrometry; honeybee; biomarker ПРОЦЕНА НА ТЕШКИ МЕТАЛИ ВО ПРОПОЛИС И ВО ПОЧВА ОД ПЕЛАГОНИСКИОТ РЕГИОН, РЕПУБЛИКА МАКЕДОНИЈАВо оваа студија, со користење на атомска апсорпциона спектрометрија, беше одредена содржината на пет тешки метали (Cr, Pb, Zn, Cd и Cu) во примероци почва и прополис, од четири локации во југозападниот дел на Македонија. Целта беше да се посочат клучните фактори кои влијаат на содржината на тешките метали во почвата и во прополис од иста локација. Општо земено, на сите локации релативните концентрации на тешки метали во почва беа со следниот опаѓачки редослед: Zn>Cr>Cu>Pb>Cd. Највисоките средни вредности од концентрациите на тешки метали во овие почви изнесуваат: 72,03; 38,28; 26,64; 17,15;0,60 mg kg -1 за Zn, Cr, Cu, Pb и Cd, соодветно, и сите тие се под целните вредности претставени во Холандската листа. Општиот тренд на содржината на тешки метали во прополисот од истите четири локации, е со следниот B. Bogdanova Popov, V. Karapetkovska Hristova, S. Presilski,M. A. Shariati, S. Najman Maced. J. Chem. Chem. Eng. 36(1), 23-33 (2017) 24 опаѓачки редослед: Pb>Cr>Zn>Cu≈Cd. Генерално, примероците од прополис од планинските локации (Орле и Ра...

Phytochemicals, mineral contents, antioxidants, and antimicrobial activities of propolis produced by Brunei stingless bees Geniotrigona thoracica, Heterotrigona itama, and Tetrigona binghami

“…All the heavy metal elements were detected at low concentrations, two to three orders lower than the mineral contents. Irrespective of the stingless bee species in this study, Cd content in their propolis was much higher as compared to those observed in propolis found in Macedonia (0.012–0.038 μg g −1 ) ( Popov et al, 2017 ) and in Poland (0.012–0.055 μg g −1 ) ( Formicki et al, 2013 ). In addition, Pb content in the propolis was also much higher compared to those in propolis found in Macedonia (0.033–0.041 μg g −1 ) ( Popov et al, 2017 ), but they tended to be lower than those in propolis found in Poland (0.89–2.94 μg g −1 ) ( Formicki et al, 2013 ).…”

“…Irrespective of the stingless bee species in this study, Cd content in their propolis was much higher as compared to those observed in propolis found in Macedonia (0.012–0.038 μg g −1 ) ( Popov et al, 2017 ) and in Poland (0.012–0.055 μg g −1 ) ( Formicki et al, 2013 ). In addition, Pb content in the propolis was also much higher compared to those in propolis found in Macedonia (0.033–0.041 μg g −1 ) ( Popov et al, 2017 ), but they tended to be lower than those in propolis found in Poland (0.89–2.94 μg g −1 ) ( Formicki et al, 2013 ). Considering that stingless bees may collect waxes, resin, nectar, and minerals from the plants and soil over a distance of sub-kilometer from their hives ( Przybyłowski and Wilczyńska, 2001 ), the low contents of heavy metals in the propolis reflect low contaminations of heavy metals in plants, soil, and atmosphere in the surrounding area where the propolis was collected.…”

“…In general, the main mineral elements in propolis are K, Mg, Ca, Mn, Na, and Al, suggesting that the propolis are very rich with respect to these mineral elements. However, the sequence going from the greatest to the smallest amount of these mineral elements depends on the stingless bee species as well as the geographical origin ( Popov et al, 2017 ), demonstrating that the minerals in propolis are originated from pollens collected by stingless bees from various flowering plants in the surrounding area of their hives ( Campos et al, 2008 , Dagaroglu, 2004 , De-Melo et al, 2015 ). This notion is also supported by the fact that K, Mg, and Ca were the most metal elements found in bee pollen collected from Turkey ( Altunatmaz et al, 2017 ), Brazil ( Campos et al, 2008 , Morgano et al, 2012 ), Serbia ( Kostic et al, 2015 ), and Chile ( González-Martín et al, 2015 ), although bee pollens were also very rich with respect to P, Fe, and Zn.…”

Toxic Metals in the Crude Propolis and Its Transfer Rate to the Ethanolic Extract

“…as observed by several authors that investigated the Serbian, Spanish, Macedonia, Italian, among others propolis (Bonvehí & Bermejo, 2013;Popov et al, 2017;Tosic et al, 2017).…”

“…According to Finger et al (2014), some potentially toxic metals are found in waste from chemical and electronic industries, especially the burning of fossilfuels such as petroleum. The increased presence of metals in CP may be indicative of contaminated environment, how verified by other authors (Bonvehí & Bermejo, 2013;Popov et al, 2017;Tosic et al, 2017). The incorporation of toxic metals into propolis may also be associated with several factors, such as the industrial activity, with the liberation of particles that can remain suspended in the air; the indiscriminate use of fertilizers and the practice of irrigation with contaminated water (Alloway, 1990;Liu et al, 2009;Sawidis et al, 2011).…”