**6. Conclusions**

Several regions in the world are suitable for honey production with different attributes due to the presence of melliferous species. However, in many cases, the apicultural activities, beehives, and the melliferous plants occur near of sources of pollution and it may produce certain changes in the composition of honey.

In the last years, the foreign trade has increased the demand for honey and beehive products without toxic residues for fulfillment of food safety policies.

Since honeybees are able to fly even 4 km per day as a maximum distance from the beehive to the floral source for collecting nectar, it is possible to detect certain undesirable compounds and/ or residual molecules from different human activities. These pollutants can be deposited onto the surfaces of melliferous plants and flowers, especially in the case of plants growing near industries, highways, or volcanoes. Likewise, abiotic factors such as air, water, and soils may be polluted with metals and they may play an important role in transferring residues to honey.

Metals are listed among the pollutant residues that can be detected in the final composition of honey, and besides, they are classified as the main group of inorganic pollutants. They can be toxic for human beings if found at levels above the permitted limits, due to damages to physiological functions of living systems and their persistence through the food chains.

One of the most remarkable problems in metals analysis is related to very low concentrations available in honey content. In addition, honey is a complex organic matrix and it has to be treated previously to chemical determination of metals by classic analytical methods for instance, inductively coupled plasma (ICP-OES) or atomic absorption spectroscopy (AAS). The chemical treatment of samples related to extraction methodologies of metals includes the calcination process and/or acid digestion. These last steps are mainly responsible for the quality of the obtained products because any loss of mass will be reflected in no reliable values.

In that way, it is very important to determine the presence of heavy metals in honey using analytical procedures to obtain reliable values. It must be considered that honey and/or another beehive product such as bee pollen, propolis, or beeswax are organic matrix and thus, a cleanup method of samples before chemical analysis for determining heavy metal content is essential for achieving optimal results.
