Wastewater-based epidemiology (WBE), as a means of obtaining drug use and abuse data, is increasingly becoming an alternative method for estimating drug usage and consumption in a population. The data obtained through WBE on drug usage and consumption is near real-time and it allows analysts to monitor current patterns and trends in novel psychoactive substances, illicit drugs, and pharmaceutical drugs. WBE can therefore be complemented with other methods of obtaining data on drug use and abuse such as survey questionnaires. The survey questionnaire is administered in communities where wastewater samples are collected. The data obtained through WBE is compared with the data obtained from survey responses and establishes a correlation if any. Through survey responses, researchers can obtain the demographic information of participants, frequency of use, and mode of administration of drugs. This research reports the use of a Gas Chromatography-Mass Spectrometry (GC-MS) method for the detection of illicit drugs and pharmaceutical drugs in wastewater collected from different sites in Botswana, introducing the analysis for the first time in the country. Online survey questionnaire responses from the Botswana International University of Science and Technology (BIUST) community on the use, disposal, and knowledge on the fate of pharmaceutical XIV and illicit drugs in wastewater are also reported. Due to the increase in the use of illicit drugs and the misuse of pharmaceutical drugs in Botswana over the years, this research had to be done to help in the fight against illicit drug use and the misuse of pharmaceutical drugs. Influent wastewater samples were collected once a month, i.e., during the initial visit to the wastewater treatment plant (WWTP), during the WWTP tour, after the last weekend of the month, after a public holiday, after a long weekend or after a major event such as a music festival or sports tournament. Eighteen influent wastewater samples were collected at Palapye- BIUST, Palapye-main village, Serowe-Radihemelo, Serowe- Mabogopa and Gaborone- Glen Valley WWTP in Botswana between July 2019 and October 2019. Samples were extracted by the Solid-Phase extraction (SPE) technique using Strata-X Drug B SPE cartridges before analysis by GC-MS. Drugs were identified in wastewater samples using scan and splitless injection. Ibuprofen and caffeine were detected and confirmed from the wastewater samples while efavirenz, prolintane, mefexamide, xylazine and amiphenazolewere only identified and not confirmed due to a lack of drug standards. An online survey questionnaire link was created via google forms and administered at BIUST between March 2021 and May 2021. A total of 120 people participated in the survey. A total of 80.5% of the respondents indicated that they used different pharmaceuticals. Painkillers such as ibuprofen and paracetamol were the most used pharmaceuticals. The results obtained also indicated that females used pharmaceuticals more than their male counterparts. Only 16.1% of the survey respondents indicated to have use different illicit drugs such as cannabis, cocaine, and methamphetamine. Hallucinogens such as cannabis were the most used class of illicit drugs.The results obtained on illicit drug use indicated that males used illicit drugs more than their female counterparts. Most of the illicit drugs users indicated that they used the drugs every day, every weekend, and the last weekend of the month. Frequency of use of pharmaceutical drugs was not recorded. Majority of both pharmaceutical and illicit drug users were in the 18-24 years age group. For disposal of leftover/expired pharmaceutical and illicit drugs, most respondents indicated that they dispose them in litter bins and down the drain. Most of the respondents also indicated that it is through reading books and research articles that they have knowledge on the fate of both illicit and pharmaceutical drugs in wastewater.XV Even though survey respondents indicated to have used different illicit and pharmaceutical drugs, these drugs were not detected in the Palapye-BIUST wastewater samples that were analyzed, as a result there was no correlation established between the BIUST online survey responses with the GC-MS results for the wastewater samples collected at the Palapye-BIUST wastewater treatment plant. Pharmaceuticals mentioned in the survey answers were not detected in wastewater samples from Palapye-BIUST WWTP, although ibuprofen was detected in other wastewater samples collected at Palapye-main village and Serowe-Mabogopa WWTP. The aims and specific of the research were successfully achieved as a GC-MS method was used to detect ibuprofen, caffeine, efavirenz, prolintane, mefexamide, xylazine and amiphenazole in wastewater samples collected at different sites in Botswana. The use, disposal, and knowledge of the fate of illicit and pharmaceutical drugs in wastewater at BIUST was also successfully achieved through administration of an online survey questionnaire to the BIUST community. A comparison of the Palapye-BIUST GC-MS results for the wastewater samples and BIUST survey questionnaire responses obtained showed that there was no correlation established between the results obtained by the two means. The research questions were also answered as we were able to identify the different illicit and pharmaceutical drugs that are used by different communities in Botswana. Results obtained from the research will help relevant stakeholders in Botswana in the fight against drug abuse as they provide the much-neededinformation on commonly used drugs, frequency of use, and demographic information of participants.

Thesis (MSc of Chemical and Forensic Sciences)---Botswana International University of Science and Technology, 2022