# Comparison of the Biological Potential and Chemical Composition of Brazilian and Mexican Propolis
## 4 Propolis Contamination
### Xenobiotics in Propolis
#### 4.1.1 Pesticides in Brazilian and Mexican Propolis  
Propolis can be polluted in direct or indirect form principally for pesticides and heavy metals of anthropogenic origin. Pesticides and heavy metals have been reported in many Hispanic and Portuguese countries.  
Much of the bee production is found close to regions where conventional crops (soyleans, corn, wheat) that use herbicides regularly are found [155]. These crops can serve as a source of raw material for propolis production by bees, or they can be close to their range of action. According to [PERSON] et al. [156], a significant part of the agricultural production areas are close to the different biomes of each region. Due to the contamination of these productive areas and the volatilization of pesticides, such as contaminating precipitation.  
Pesticides (mainly systemic herbicides) can be deposited on plants and trees. These plants can absorb toxic compounds through their leaves or roots and translocate them to other parts of the plant, such as buds [157; 158; 159], so bees will come into contact and can transfer these compounds to bee products, including propolis.  
Studies of pollutants in Mexican and Brazilian propolis are very scarce. As shown in Table 4, there are two scientific works in each country regarding the verification of the presence of pesticides. Among the various pesticides investigated, only Organophosphate [160] was found in a propolis sample from southern Mexico. In a study carried out with propolisis from Brazil [15], they verified the presence of AMPA and Atrazine in 32% of the samples evaluated.  
Pesticides in Chilean raw propolisis detected triadimefon on concentrations in mg/kg\({}^{-1}\) until to 0.95 and Dicofol 0.54 and in Spanish propolisis triadimefon 2.65, dicofol 1.2, dichoflulu- amid 0.38, procymidone 0.36, Folpet 3.74, and metazachlor 1.3 mg kg\({}^{-1}\)[161]. In processed propolisis (capsules, tablets, tinctures, candies, and syrups) from Spain, Portugal, and Chile report pesticide in mg/kg of quintozene 1.06, procymidone 0.11, metazachlor 6.09, folpet 11.31, dicholfuani 0.29, and chlorefenson 1.05 [162]. Other study found counamphos in an  
\begin{table}
\begin{tabular}{l l l l} \hline \hline
**Veterinary Diseases** & **Microorganisms** & **Product with Propolis Extract** & **Author** \\ \hline Effect canine dermatopthytosis effect in dogs & _Microsporum sygveum_ & Soap & [147] \\  & _Microsporum cantis_ & & \\ \hline Treatment of Dermatomyosis in Horses & _Trichophyta tomatengraphytes_ & Shampoo & [148; 149] \\ \hline Post-surgical Treatment of Caseous & _Corynebacterium_ & & \\ Lymphadenitis in Sheep & _pseudotuberculosisis_ & Ointment & [79] \\ \hline \hline \end{tabular}
\end{table}
Table 3: Veterian products with propolisis extract.  
Generally, if there is a presence of toxic compounds in propolisols, other bee products, mainly honey, can be contaminated. [PERSON] et al. (2016) present a complete pesticide analysis in honey and wax from Altiplano, Northern, and Peninsula of Yucatan in the highest concentrations were the phenyl phenol and the organochlorine 2,4\({}^{\prime}\)-DDT in the south; malathion, chlororprifos, phenyl phenol, and thiabendazole in the Northern Mexico; and chlororprifos and imidacloprid in Altiplano. These results demonstrate the pesticide exposure in the Mexican beehives. In Brazil in 1% and 44% of honey samples evaluated were found pesticides ([PERSON], 2016; [PERSON] et al., 2017), respectively. [PERSON] et al. (2017) found pesticides in 7% of pollen samples analyzed.  
Overall, environmental contamination by agrochemicals is being associated as a significant factor in the decline of insects, including bees and other pollinators ([PERSON], 2016; [PERSON], 2016; [PERSON], 2016). Researchers relate to evidence of a decrease in the population of bees and even their mortality to exposure to pesticides ([PERSON], 2016; [PERSON], 2016; [PERSON], 2016; [PERSON], 2016).