3.1.1. Insecticides

Thiacloprid was detected in 90% of honey samples (max 0.337 mg/kg), acetamiprid in 86.7% (max 0.061 mg/kg), carbendazim in 60% (max 0.049 mg/kg), DMF in 56.7% (max 0.038 mg/kg), amitraz in 53.3% (max for total 0.075 mg/kg), thiamethoxam in 26.7% (max 0.004 mg/kg), thiacloprid-amide in 13.3% (max 0.012 mg/kg), dimethoate in 10% (max 0.003 mg/kg), azoxystrobin in 10% (max 0.002 mg/kg), tebuconazole in 6.66% (max 0.002 mg/kg), and boscalid in 3.33% (max 0.001 mg/kg) (Table 3). All the samples of rapeseed honey contained residues of thiacloprid, acetamiprid, and carbendazim (0.0702 mg/kg, 0.0300 mg/kg and 0.0242 mg/kg), and all the samples of multifloral honey contained thiacloprid and acetamiprid (0.1062 mg/kg and 0.0150 mg/kg) (Table 4). The highest degree of contamination with pesticides was noted for multifloral honey (0.1646 mg/kg in total) and rapeseed honey (0.1498 mg/kg), while buckwheat (0.0324 mg/kg), honeydew (0.0125 mg/kg), and linden (0.0268 mg/kg) honey were less contaminated with pesticides. All the samples of buckwheat honey were contaminated with the neonicotinoid insecticide thiacloprid (0.0122 mg/kg). Mitchell et al. [19], in an analysis of the presence of five commonly used neonicotinoids (acetamiprid, clothianidin, imidacloprid, thiacloprid, and thiamethoxam) in 198 samples of honey from various parts of the world, showed the regional differences in the use of different types of pesticides. Imidacloprid was predominant in honey from Africa and South America, acetamiprid in samples from Asia, thiamethoxam in honey from Oceania and North America, and thiacloprid in European honey. Under the Commission Implementing Regulation (EU) No 2020/23 [23], the approval of thiacloprid as an active substance was not renewed, and stores of it were to be used by 3 February 2021. At the same time, the European Food Safety Authority (EFSA) indicated a problem raising serious concern associated with the contamination of groundwater by the metabolites of thiacloprid [24]. All the suggested applications of thiacloprid entail the risk of exceeding the acceptable limit (0.1 μg/L) of the metabolites M30, M34, and M46 in drinking water. These metabolites are assumed to have the same carcinogenic properties as the original active substance (thiacloprid), which—according to Regulation (EC) No 1272/2008 of the European Parliament and of the Council [25] (amended by Commission Regulation (EU) 2019/521 [26])—is a category 2 carcinogen. This category includes agents, mixtures, and groups of agents for which there is sufficient evidence of carcinogenicity in humans as well as those for which there is no evidence of carcinogenicity in humans, but where there is evidence of carcinogenicity in experimental animals. In addition, thiacloprid is classified as a category 1B reproductive toxin. This group includes compounds presumed to adversely affect reproduction in humans based on experiments in animals.


**Table 3.** Descriptive statistics of pesticide residues (mg/kg) detected in honey.

**Table 4.** Descriptive statistics of pesticide residues (mg/kg) detected in varietal honeys (RS—rapeseed; MF—multifloral; BW—buckwheat; HD—honeydew; LI—linden).


The contamination of honey with neonicotinoid insecticides largely depends on the apiary's location in an agricultural area transformed by human activity [9]. A comparison was made of 90 samples of honey from western France, obtained from an apiary located on a plain and surrounded by crops and from another apiary situated in a bocage environment (fields surrounded by shrubs and trees). The levels of thiacloprid and thiamethoxam were higher in the honey from the apiary in the plain (11.6 ng/g and 2 ng/g) than in the honey from the bocage (9.1 ng/g and not detected). On the other hand, the maximum level of acetamiprid in the honey from the bocage (112.8 ng/g) was higher than in the honey from the plain (51.9 ng/g).

Our study found no residues of organochlorine insecticides in the honey samples. Wilczy ´nska and Przybyłowski [27], on the other hand, detected eight organochlorine insecticides in honey from Poland, including HCH and *p*,*p* -DDT (about 60% of samples), *p*,*p*-methoxychlor (29% of samples), and aldrin (21% of samples). Organochlorine pesticides are especially hazardous in agriculture due to their persistence and bioaccumulation in the environment, and their residues are identified in honey in various parts of the world.

Ruiz-Toledo et al. [28] demonstrated the presence of a wide spectrum of organochlorine compounds in honey from Mexico (in the state of Chiapas), despite the fact that their use has been banned there since 2000. At least one organochlorine pesticide was present in more than 90% of honey samples—the most frequently identified were heptaclor (44% of samples), γ-HCH (36%), DDT (19%), endrin (18%), and DDE (11%).

The EFSA [24] reported that among 1301 samples of honey and other bee products evaluated in 2019, 78.7% were free of pesticide residues, and 20.4% of samples contained residues at the maximum level (MRL) or lower. The MRL was exceeded in 0.9% of samples. In total, 27 pesticides were quantified: most frequently thiacloprid (173 samples), acetamiprid (49 samples), amitraz (37 samples), dimoxystrobin (29 samples), azoxystrobin (27 samples), glyphosate (17 samples), coumaphos (10 samples), and flonicamid (10 samples). The MRL was exceeded for amitraz (four samples), glyphosate (two samples), and in one sample each for acetamiprid, bromide ion, thiacloprid, azoxystrobin, boscalid, and chlorfluazuron.

El-Nahhal [29] identified residues of 92 pesticides in honey from 27 countries, including 6 substances belonging to toxicity class IA (extremely hazardous), 8 from class IB (highly hazardous), 42 from class II (moderately hazardous), 35 from class III (slightly hazardous), and one from class IV (not posing a serious threat). The hazard indices (HI) indicated a high potential health risk from honey consumption.

Barga ´nska et al. [30], in an analysis of residues of 30 pesticides in honey from northern Poland (Pomerania), detected them in 29% of samples. In five samples (11%), the MRL was exceeded for bifenthrin (14.5 ng/g), fenpyroximate (16.3 ng/g), methidathion (25.7 ng/g), spinosad (20.6 ng/g), thiamethoxam (20.2 ng/g), and triazophos (20.3 ng/g). The organophosphate pesticide profenofos, which was not found in the present study, was detected as well (from <LOQ to 17.2 ng/g). In turn, Gaweł et al. [20] monitored 155 samples of Polish honey for the potential presence of 207 pesticide residues from 2015–2017. A total of 21 pesticides were identified: thiacloprid, acetamiprid, carbendazim, DMF and DMPF (amitraz metabolites), azoxystrobin, tebuconazole, dimethoate, boscalid, coumaphos, cyproconazole, flutriafol, tau-fluvalinate, tetraconazole, diazinon, dimoxystrobin, *p*,*p* - DDD, difenoconazole, lindane, propiconazole, and prothioconazole-desthio. The most frequently detected pesticides were two cyano-substituted neonicotinoids—thiacloprid and acetamiprid—and carbendazim, which were found in 68%, 55%, and 38% of honey samples, respectively. In the present study, the presence of residues of these substances was detected in 90%, 87%, and 60% of samples. Moreover, Gaweł et al. [20] reported acetamiprid concentrations in honey ranging from 0.001 to 0.13 mg/kg and thiacloprid concentrations from 0.001 to 0.2 mg/kg. The maximum content of acetamiprid in the present study (0.061 mg/kg) was half of that reported in the cited study, while that of thiacloprid (0.337 mg/kg) was higher.
