These findings warrant further exploration, and may indicate a need for the development of additional,novel protections for privacy and legal and clinical care consequences and improved means of relaying such protections to patient populations. It also supports the value of triangulation of data from multiple sources. Aerobiological monitoring of pollen grain concentrations in the atmosphere is useful for detecting anomalies in the biodiversity of anemophilous species and the climate . Sufficiently extensive records of airborne pollen data can therefore be considered suitable bio-indicators to assess the behaviour, conservation and pollination disturbances of vegetation .Long-termpollen databases provide excellent means for studying the effects of climate change on pollen-producing plants . In addition, they offer the possibility of establishing forecasting tools such as regression models, time series or the use of artificial intelligence . These tools are essential for many specific applications , such as helping people avoid allergenic elements.It is an herbaceous, usually dioecious plant, although it can also be monoecious. It has been widely used to produce fibre , bird food ,vertical grow rack essential oils and narcotics. Some controversy about its taxonomy exits, but it is classified as a single Cannabis species, C. sativa .

Some of its varieties are cultivated to produce marijuana or hash from the resin found in the stalks, young leaves and flowers, and it is oneof the oldest known psychoactive substances . Industrially grown hemp must contain less than 0.2% tetrahydro cannabinol, and its cultivation from EU-certified seeds does not require a licence.In the 1961 Single Convention on Narcotic Drugs, Cannabis is described as the flowering or fruited tops of the Cannabis plant from which the resin has not been extracted . Its cultivation requires authorisation from the Spanish Agency for Medicines and Medical Devices. In 2020, the WHO removed Cannabis from Schedule IV of the Convention, thereby recognising its potential medicinal properties. However, its recreational use is prohibited in Spain.Cannabis also produces large amounts of pollen .A single flower can release more than 350,000 pollen grains into the environment. This pollen is dispersed by wind,meaning it can be transported over long distances .The presence of Cannabis pollen in southern Spain has been reported as a result of transport from northern Africa . For instance, Cannabis pollen levels increased in the city of Málaga between 1992 and 2015 . This pollen type does not appear in the work by Fernández Rodríguez in Extremadura, a region located in the central-western part of Spain, but it does appear in a study by Maya Manzano of the same region.

This increase in Cannabis pollen in recent years may be a consequence of illegal Cannabis cultivation in cities,cannabis grow racks resulting in local or regional transport of Cannabis air masses.An interesting question to consider is whether the presence of this pollen type corresponds to transport from distant areas, like northern Africa,or whether it is a consequence of increased cultivation in areas close to the sampling points. One of the most commonly used atmospheric transport and dispersion models in the scientific community is HYSPLIT , provided by the Air Resources Laboratory of the National Oceanic and Atmospheric Administration. This model displays weather forecasts and reproduces the trajectories of an air parcel and the results of its dispersion model through a series of interactive web pages . It is a hybrid between the Lagrangian approach,which tracks air parcels moving from their initial locations, and the Eulerian method, which uses a fixed three-dimensional grid to observe the movement of air masses .HYSPLIT back trajectories allow users to trace air mass origins and their paths at different times, helping to identify particle transport at varying altitudes.This model has been used for many applications, such as the description of atmospheric transport, dispersion and deposition of airborne dust, allergens or atmospheric pollutants, smokes, volcanic ash or radionuclides,among others .Air masses from African deserts transport large amounts of biological particles, such as pollen grains, fungal spores, bacteria and viruses, as well as different protein or lipid components .

The incidence of these air masses over the southeastern Iberian Peninsula is relatively high compared to other peninsular enclaves. For example, about 30%of the days in 2004 coincided with North African air masses .The aim of this work is to analyse the behaviour of Cannabis taxon concentration time series in Cartagena , Murcia  and Lorca , the three most populated cities in the Region of Murcia. We study the relationship these concentrations have to the meteorology to establish the origin of Cannabis pollen in the Region of Murciaby analysing back trajectories generated with the HYSPLIT model. We determine whether the transport has been local or long-distance from airmass origins. Aerobiological samples were collected using a Hirst-type trap, model VPPS 2000, from Lanzoni S.R.L .