A Systematic Review and Meta-analysis on Blood Lead Level in Opium Addicts: an Emerging Health Threat

Blood-lead level in humans and drug addiction: a comprehensive study in Iran

Drug abuse has a high prevalence worldwide and causes many health-related disorders. There are limited human exposure studies on establishing lead exposure levels and their propensity for drug addiction. In the present study, blood samples were tested for lead (Pb) concentrations in illicit drug users together with the related symptoms in comparison with control group of non-drug users. The study was performed on 250 volunteers divided equally in four drug groups, namely, opioids, hashish, methadone, and methamphetamine, and one control group of non-drug users. Participants were recruited from drug addiction clinics and camps in Kashan city, Iran, who were using drugs continuously for more than 1 year. Control group was recruited from companions of the patients with no drug use history. In the investigated groups of drug users, the highest blood-lead level (BLL) concentrations were observed in the opioid group (mean 37.57 µg/dL) with almost 3.7 times higher than in the control group (mean 3.39 µg/dL). In the methamphetamine group, type of occupation had the significant association with BLL concentrations. The positive correlation was revealed in the opioid and methadone groups for BLL concentrations and the duration of drug usage. In the opioid group, the highest BLL concentrations were observed among users who used both methods of drug use: smoking and eating. Also, several behavioral and life-style factors were identified which influence the blood-lead concentration in the drug users. The results of our study revealed that the BLL concentrations in investigated drug users' groups were significantly higher than in the control group (P < 0.001). That can be related with the Pb contents in illicitly used drugs. Apart other adverse health effects, long-term illicit drug use might cause to lead poisoning.

A Pilot Study on the Association of Lead, 8-Hydroxyguanine, and Malondialdehyde Levels in Opium Addicts' Blood Serum with Illicit Drug Use and Non-Addict Persons

While a large body of literature has shown the health problems of illicit drug use, research is needed on how substance abuse impacts DNA damage and contaminants in blood, especially given Pb-contaminated opium. This pilot study aimed to evaluate the levels of lead (Pb), 8-hydroxy di-guanine (8-oxo-Gua), and malondialdehyde (MDA) in the blood serum of opium addicts and non-addict people. The current study is a case–control study with a cross-sectional design. A sample of 50 opium-addicted and non-addict adults were chosen for this study using convenience and random sampling methods. Participants were divided into two groups: addicts and non-addicts. The atomic absorption spectroscopy method was used to measure the quantity of Pb, and the Enzyme-Linked Immunosorbent Assay (ELISA) method was used to measure the amount of 8-oxo-Gua and MDA. The data were analyzed using an independent t-test. The results show that the amount of Pb in the blood serum of addicted women and men was higher than levels in non-addict men and women, for the study participants (p-value = 0.001). Blood levels were not significantly different between addicts and non-addicts for men or women for 8-oxo-Gua (p-value = 0.647 for women and p-value = 0.785 for men) and MDA (p-value = 0.867 for women and p-value = 0.995 for men). In general, addicts’ blood Pb levels were found to be substantially higher than those of normal non-addict persons in this pilot study. As a result, testing for blood Pb levels in addicts may be informative in instances when symptoms are inconclusive.

Opium, street opium and cancer risk

Opium is defined as the air-dried latex obtained by incision from the unripe capsules of Papaver somniferum L. Opium is a complex mixture that contains approximately 10% morphine and 2% codeine. It is commonly used to prepare opium tinctures for people with chronic diarrhea. Morphine and related opioids are powerful but highly addictive analgesics; designing less addictive opioids is an active area of pharmaceutical research that may lead to significant improvements in chronic pain management. Recently, the International Agency for Research on Cancer (IARC) classified opium consumption as carcinogenic to humans (Group 1) based on sufficient evidence of carcinogenicity in human studies. However, all human studies analyzed by the IARC Working Group included participants who consumed opium that was mixed, adulterated, and/or contaminated with known and probable human carcinogens (e.g., tarry residues of combusted opium, arsenic, lead, and chromium). The Working Group considered that these carcinogens were part of the complex mixture that opium is, rather than co-exposure or confounders. No evidence of carcinogenicity was available for pure opium in human, animal, or mechanistic studies. To avoid confusion and concern in health professionals and patients using medicinal opium preparations, and in scientists involved in the design and development of new opium derivatives, opium should be classified in Group 3 (not classifiable as to its carcinogenicity to humans). The term 'street opium' could be used to refer to opium that probably contains human carcinogens not present in pure opium, and should remain in Group 1 (carcinogenic to humans).