Heavy Metals and Pesticides on Contaminants of Concern in Cannabis

Introduction

Evidence suggests that Neolithic people from the Near East arrived in Ireland during the fourth millennium BCE (Cassidy et al., 2016), but little is known about the food and fibre plants they used at this time. Carbonized seeds of hemp (Cannabis sativa L.) were discovered at a Celtic archaeological site in what is now Hungary, dating back to the 1st century BCE (Dalnoki & Jacomet 2002). Archaeological and pollen records suggest that cannabis first arrived in the British Isles no later than the Roman period, when it quickly gained importance as a staple crop, a source of fibre, and a medicine (Dark 2000). The Lacnunga, an Anglo-Saxon medico-religious document from the 10th century, had a “Rite for Salve, Partly Irish” that used hemp as one of several topical herbal elements (Grattan & Singer 1952). (p. 123). Despite this one mention, it is challenging to document any other uses of hemp in the folk medicine or ethnobotany of Ireland. Although its relative, Humulus lupulus, was widely used at an early date, (Allen & Hatfield, 2004), no information on hemp is included in this reference. Neither does a classic work on the ethnobotany of Ireland (Moloney 1919).

In the early 19th century, hemp was produced in Ireland for fibre; at the time, it was estimated that 14,000 tonnes were necessary to supply Great Britain in a year of peace (Besnard 1816), with the author recommending that Ireland contribute more to its provision as a superior crop than flax linen. A local hemp fabric sample was also praised with the following praise: “This hemp [grown in Bunratty, Ireland] has all the properties of the Italian, and was especially well fitted for exquisite Works.” As a result of human activity, the annual herb cannabis (Cannabis sativa L.) can now be found and grown in almost every biome on Earth, from the tropics to the foothills of the Himalayas. Seed oil, intoxicating resin, medicine, and textile fibre all come from this ancient plant (Kriese et al. 2004; Zuardi 2006). According to archaeological evidence, Cannabis was first cultivated in China for its fibre, and then it was exported to the Middle East, Europe, and South America in the early 16th century (Nelson 1996; Schultes et al. 1974). For thousands of years, people have been dispersing and altering this species, making it impossible to trace back its original range. The Canadian settlement of Port Royal was responsible for introducing hemp growing to the New World in 1606 (Small & Marcus 2002).