Organochlorine Pesticides (Aldrin, DDT) and PCBs in Market Available Cigarettes in Abeokuta, Ogun State, and Their Health Risks

Keywords

DDT; Aldrin; Polychlorinated Biphenyls; Cigarettes; Human Health; Cancer.

Abstract

Cigarette smoking, or tobacco consumption, remains a significant health concern around the world. While there has been more focus on the harmful effects of nicotine in cigarettes, only little is known about some other components such as Polychlorinated biphenyls and organochlorine pesticides like DDT and Aldrin, which are used on tobacco farms. Human exposure to pesticide residues on tobacco occurs when residues remaining in cigarette smoke are inhaled.

This study was carried out with the aim of (i) investigating the concentration levels of organochlorine pesticides (Aldrin and DDT) and PCB in ten Market available cigarettes in Abeokuta, Ogun State, and (ii) assess the human health associated with the concentration levels found in the cigarettes.

The Mean concentration ranges of the pesticides in the cigarette samples were as follows; Aldrin (0.015µg/g - 0.048µg/g). DDT (0,116µg/g - 0.330µg/g), and PCB (0.223µg/g - 0.567µg/g). From the analysis, the hazard quotient for the pesticides and PCB were also very low and unable to cause any health problems, with the cancer risk in them also at a very minimal level. However, PCB is more likely to be carcinogenic due to its high cancer risk values, though it might not have a significant effect in contributing to non-carcinogenic adverse effects, just like with DDT and Aldrin.

Citation

Olatunde Bello H (2024) Organochlorine Pesticides (Aldrin, DDT) and PCBs in Market Available Cigarettes in Abeokuta, Ogun State, and Their Health Risks. SM J Environ Toxicol 7: 8.

INTRODUCTION

Pesticides are any substance or mixture of substances of chemical or biological ingredients intended for repelling, destroying, or controlling any pest, or for regulating plant growth [1]. Pesticides and agrochemicals, in general, became an important component of worldwide agriculture systems during the last century, allowing for a noticeable increase in crop yields and food production [2].

Use of plant protection chemicals, mainly pesticides, has become integral part of modern agricultural production systems around the world, not only to protect the crop but also to secure the optimum crop yield [3]. Organochlorine pesticides (also called chlorinated hydrocarbons) are organic compounds attached to five or more than five chlorine atoms. They represent one of the first categories of pesticides ever synthesized and are used in agriculture [4].

In 1972, over twelve thousand tons of pesticides were used on tobacco crops, and according to a study to determine the chlorinated pesticide residue levels in mainstream smoke, the rate of transfer of pesticides from tobacco into smoke averaged about 12% of that in the tobacco before combustion [5]

Pesticide residue can remain on tobacco leaves after harvesting and processing them into their manufactured forms. When tobacco is smoked, these residues, along with the tobacco and other additives, are burnt, and the resultant smoky mixture inhaled by active and passive smokers is known as pyrolysis products [5].

Effects of Pesticides on Humans

The characteristics of pesticides, such as high lipophilicity, bioaccumulation, long half-life and potential of long-range transport, have increased the chances of contaminating the air, water and soil, even after many years of application [6]. Due to lack of proper legislation, improper market regulations and ignorance shown by people, agricultural workers from developing countries are prone to experience high levels of agricultural chemicals, including pesticides [7]. Among agriculturalists of developing countries, pesticide exposure is the primary occupational hazard, which leads to health issues and environmental contamination associated with pesticide use [8-12]. Organochlorine pesticides may alter the proper function of the nervous system of the insects leading to disorders such as convulsions and paralysis followed by eventual death [13].

Aldrin

Aldrin is a colorless organochlorine insecticide spread to soils to kill termites, grasshoppers, corn rootworm, and other insect pests. It is highly lipophilic and its solubility in water is only 0.027 mg/L, which intensifies its persistence in the environment [14]. Aldrin is a synthetic organochlorine pesticide that is used as a broad-spectrum soil insecticide for protection of food crops, and as seed dressing for the control of pests such as ants and termites [15]. Aldrin exposure among the general population may result via dietary intake, however over time, it has become harder to find aldrin residue in food. Neurotoxic symptoms in humans include headache, dizziness, general malaise, muscular twitching, vomiting, or myoclonic jerks after prolonged exposure to lower dosages of these substances [15].

Dichlorodiphenyltrichloroethane (Ddt)

In 1940s, DDT was used as the first modern synthetic insecticide to control insect in agriculture, housing, institutes and to combat insect-borne human diseases [16]. Although DDT use has generally been restricted since the early 1970s, exposure to the pesticide remains widespread [17]. Until present, there is no substitute for DDT in terms of comparable efficiency and operational possibility on vector-borne diseases control [18]. DDT was classified into class II (moderate toxic) in the WHO classification system for pesticides [19]. DDT exposure can occur by eating, breathing, or touching products contaminated with DDT [20]. Following exposure to high doses, human symptoms can include vomiting, tremors or shakiness, and seizures. Laboratory animal studies show DDT exposure can affect the liver and reproduction. DDT is a possible human carcinogen according to U.S. and International authorities [17].

Polychlorinated Biphenyls (Pcbs)

PCBs were first produced commercially in the 1920s, although it was not until the 1950s that the industrial application of PCBs increased significantly [21]. PCBs build up throughout the food chain. They spread to and concentrate in the liver and fat tissue after being quickly absorbed from the digestive system [22]. PCB exposure, especially during fetal and early life, reduces IQ and alters behavior. The PCBs alter thyroid and reproductive function in both males and females and increase the risk of developing cardiovascular and liver disease and diabetes. Women are at high risk of giving birth to infants of low birth weight, who are at high lifetime risk for several diseases [23].

Pesticides in Cigarettes

Manufacturers have described the cigarette as “a drug administration system for the delivery of nicotine in acceptable and attractive form” [24]. Smokers are exposed to a toxic mix of over 7,000 chemicals when they inhale cigarette smoke. The harmful chemicals in cigarette smoke can damage nearly every organ in the body. Nonsmokers are exposed to many of these same chemicals through secondhand smoke [25]. Pesticides sprayed on tobacco plantations are among the over 5,000 chemicals that can be found in tobacco products [3,26,27]. When tobacco is smoked, these residues can be degraded but usually not destroyed. Due to the huge number of toxic chemicals, the presence of pesticides in tobacco products and smoke is not treated as an additional alarming issue [5]. The wide range of pesticides used on tobacco crops includes Dichlorodiphenyltrichloroethane (DDT) and lindane, two organochlorine compounds whose use is today limited due to their toxic effects on both environment and human health [28]. DDT also belongs to the 98 tobacco smoke components for which risk assessment authorities have established a human inhalation risk value for cancer [29].

MATERIALS AND METHODS

Sample Collection

The cigarette samples were collected at Osiele Market in Abeokuta, and transported to the Environmental Management and Toxicology Laboratory at the Federal University of Agriculture, Abeokuta, Ogun State, Nigeria. The samples include 10 different brands of cigarettes popular in Nigeria.

Sample Preparation

Each cigarette wrap was torn to remove the tobacco content for easier access to take samples for weighing. The dried tobacco samples were then wrapped in a white sheet of paper, after which small portions were gradually taken for weighing.

Sample Extraction

Exactly 2.0g of each tobacco sample was weighed twice into separate centrifuge tubes to serve as duplicate samples. In each centrifuge tube containing the weighed tobacco sample, 4ml of Formic acid was added to facilitate digestion. The tube was then placed in a water bath for 30 minutes at 90C and allowed to cool at room temperature. Thereafter, approximately 4ml of hexane was added, after which it was shaken for 5 minutes and centrifuged at 4000 revolutions per minute for 3 minutes. After centrifugation, two layers were obtained, comprising of the top and bottom layers. The top hexane layer was transferred into a clean sample vial using a teat pipette. Another 4ml of hexane was subsequently added to the centrifuge tube containing the residue, and extraction was repeated, followed by the subsequent transfer of the top hexane layer into the same sample vial. The extraction was repeated for a third time by adding 4 ml of ethanol into the centrifuge tube containing the residue, after which it was centrifuged. The top layer obtained is subsequently transferred into the sample vial used for extract collection.

Pesticide Analysis

Samples were analyzed by the use of a model PAS-1701 gas chromatograph (Agilent, GC Model 68900) equipped with a fused capillary column of (30m length × 0.32mm i.d. and 0.25-µm film thickness). Oven temperatures were programmed from an initial temperature of 160οC for 1 min, ramped to 260οC at a rate of 5οC/min, and then held at 260οC for 15 min. Nitrogen was then used as the carrier gas at a flow rate of 3mL/ min. Residues were detected using an Electron Capture Detector (ECD).

Data Analysis

Organochlorine pesticide data were subjected to simple descriptive (mean and standard deviation) and inferential (Duncan Multiple Range Test) statistics using SPSS for Windows (version 22.0).

Health risk assessment

The health risk assessment of OCPs was calculated for Average Daily Dose (ADD), Hazard Quotient (HQ), Hazard Index (HI), and Cancer Risk (CR), using the formula highlighted by USEPA.

Where, ADD = Average daily dose (mg kg-1 day-1)
C = Concentration of OCPs in cigarette (mg kg-1),
IRing = Ingestion rate of cigarette (50 mg day-1),
IRinh = Inhalation rate of cigarette (20 m-3 day-1),
ED = Exposure duration (years) = 30 years for carcinogenic effects for adults,

EF = Exposure frequency (day/year) = 365 days year-1,
CF = Conversion factor = 10-6 kg mg−1 (4.2 x 10-2)
PEF = Particle emission factor = 1.36 x 109 m3 kg−1
AT = Averaging time or life expectancy = 54.5 years,AT = ED for non carcinogenic effects,
BW = Body weight (kg); 60 kg for an adult.

Where, ADD =Average daily dose (mg kg-1 day-1),
RfD =Reference dose (mg kg-1 day-1),
N=numbers of observed elements.
HQ > 1 denotes adverse health effects; HQ < 1 indicates no adverse effects,

Cancer Risk = ADD x SF (4)

Where, ADD = Average daily intake (mg kg-1 day-1),

SF = Slope factor (mg-1 kg day)

RESULTS AND DISCUSSION

The Mean Concentrations of Selected Organochlorine Pesticides; Aldrin, Dichlorodiphenyltrichloroethane (DDT), and Polychlorinated Biphenyls (PCBs) in cigarette samples from Osiele market in Abeokuta are shown in Table 2. The mean concentration of Aldrin ranges between 0.048 ± 0.001 µg/g and 0.015 ± 0.001 µg/g, DDT ranges between 0.330 ± 0.002 µg/g and 0.116 ± 0.002 µg/g, and PCB ranges between 0.567 ± 0.001 µg/g and 0.223 ± 0.001 µg/g.

Table 1: Names of the 10 selected cigarette brands

Table 2: Descriptive statistics of OCPs (µg/g) and PCB (µg/g) in cigarette

Tables 3 and 4 also show the Hazard Quotient and Cancer risk of each organochlorine pesticide as determined for each brand.

Table 3: Hazard quotient values of OCPs and PCB in cigarette

Table 4: Cancer risk values of OCPs and PCB in cigarette

DISCUSSION

Analysis of the mean concentration, as shown in Table 2, shows that the pesticide residue Aldrin has the lowest concentration of pesticides in the cigarettes. The brand with the highest concentration of Aldrin is Pall Mall, with a concentration of 0.048 µg/g, which varies widely from the concentration found in Rothmans Menthol, 0.015 µg/g, having the lowest concentration of Aldrin. The analysis also shows that PCB has the highest overall concentration of Pesticides. The cigarette brand, Pall Mall, has the highest concentration of 0.567 µg/g compared to the Time, which has the lowest PCB concentration with 0.223 µg/g. For DDT, overall concentration is just below that of PCB, and the result shows that Pall Mall has the highest concentration, 0.330 µg/g, while Edge has the lowest concentration, 0.116 µg/g.

Table 3 shows the analysis of the hazard quotient for all the pesticides in each cigarette brand. For Aldrin, Pall Mall has the highest hazard quotient at 0.00132, while Rothmans Menthol has the lowest at 0.00042. For DDT, Pall Mall recorded the highest value at 0.00055, while Edge recorded the lowest at 0.00019. For PCB, Pall Mall was determined to have the highest hazard quotient with 0.0263, compared to the value for the cigarette brand, Time, which has the lowest value of 0.00929. However, since a hazard quotient less than or equal to 1 indicates that adverse effects are not likely to occur and can be considered negligible,this means that the possibility for non-cancer health hazards to occur is extremely unlikely in all the selected cigarettes because they all have a hazard quotient less than one.

Figure 1, which shows the Hazard Index, also indicates that the cumulative values of all the hazard quotients will still be very unlikely to cause any problems as they all sum up to less than one. However, from Figure 2, which shows the contribution of these pesticides and PCB to non-carcinogenic adverse effects, PCB is more likely to pose a risk than Aldrin and DDT, both of which remain highly unlikely to cause any adverse effects.

Figure 1: Hazard index values of OCPs and PCB in cigarettes

Figure 2: Contribution of OCPs and PCB to non-carcinogenic adverse effects

Table 4 also shows cancer risk values of Aldrin, DDT, and PCB in the selected cigarettes. Since the risk of cancer due to exposure to a contaminant is commonly expressed in exponential terms of between 10-6 and 10-4 (USEPA, 2018), it can be seen that values for Aldrin and DDT are not within this range. However, for PCB, certain brands, such as B&H Switch, Bohem, Royal Standard, Edge Change, Edge, Rothmans, and B&H Special Filter, all fall within the possible risk range. Since they all have values ranging between 1.1 x 10-6 and 1.5 x 10-6, this means that the likelihood of cancer caused by PCB is one in 1,000,000, with other values not within this range having no possible risk factor.

Figure 3 shows the sum of cancer risk values, still indicating a low possibility of causing cancer. As also shown in Figure 4, PCB was determined to be more likely to cause cancer compared to the levels of Aldrin and DDT.

Figure 3: Sum of cancer risk values of OCPs and PCB in cigarette

Figure 4: Sum of cancer risk values of OCPs and PCB in cigarette

CONCLUSION AND RECOMMENDATIONS

The above study shows the likelihood of organochlorine pesticides and PCB posing a potential risk factor in cigarettes. In the brands of cigarettes selected for this study, Polychlorinated Biphenyls (PCB) were present in greater amounts than seen for DDT and Aldrin, with Pall Mall being the brand with the highest amount of organochlorine pesticides and PCB.

In general, the study also shows that there is no significant amount of organochlorine pesticide that can cause serious health problems in the selected brands. However, PCB is more likely to be carcinogenic due to its high cancer risk values, though it might not have a significant effect in contributing to non-carcinogenic adverse effects, just like with DDT and Aldrin.

Controlling pesticide use when growing Tobacco is absolutely essential due to the negative effects these pesticides could potentially have on human health. Regular education and awareness campaigns on the risks of PCB exposure due to tobacco use or cigarette smoking should be conducted.

Additionally, the government should strongly oppose the import of pesticides. Also, to be avoided is soil that has been exposed to these chemicals. Pests should be managed using biological, cultural, and other less dangerous pest management techniques.

ACKNOWLEDGEMENTS

First and foremost, I would like to Thank God for the successful completion of this project work. My sincere appreciation also goes to my undergraduate supervisor, Professor Olukayode Bamgbose, who was always there to provide advice on how to go about my research and report. I also appreciate my parents and siblings for their support and encouragement throughout the course of my research.

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

REFERENCES

1. Food and Agriculture Organization of the United Nations. Q&A on pests and pesticide management. FAO; 2021.

2. Alexandratos N, Bruinsma J. World agriculture towards 2030/2050: the 2012 revision. FAO; 2012.

3. Khan ZS, Ghosh RK, Girame R, Utture SC, Gadgil M, Banerjee K, et al. Optimization of a sample preparation method for multiresidue analysis of pesticides in tobacco by single and multi-dimensional gas chromatography-mass spectrometry. J Chromatogr A. 2014; 1343: 200-206.

4. Abubakar Y, Tijjani H, Egbuna C, Adetunji CO, Patrick-Iwuanyanwu KC. Pesticides, history, and classification. Natural Remedies for Pest, Disease and Weed Control. 2020; 29: 29-42.

5. Chapman S. “Keep a low profile”: pesticide residue, additives, and freon use in Australian tobacco manufacturing. Tob Control. 2003; 12: 45-53.

6. Jayaraj R, Megha P, Sreedev P. Organochlorine pesticides, their toxic effects on living organisms and their fate in the environment. Interdisciplinary Toxicol. 2016; 9: 90-100.

7. Kim JH, Smith A. Distribution of organochlorine pesticides in soils from South Korea. Chemosphere. 2001; 43: 137-140.

8. Coronado GD, Thompson B, Strong L, Griffith WC, Islas I. Agricultural task and exposure to organophosphate pesticides among farmworkers. Environ Health Perspectives. 2004; 112: 142-147.

9. Konradsen F, van der Hoek W, Cole DC, Hutchinson G, Daisley H, Singh S, et al. Reducing acute poisoning in developing countries—options for restricting the availability of pesticides. Toxicol. 2003; 5: 249-261.

10. Mancini F, Van Bruggen AH, Jiggins JL, Ambatipudi AC, Murphy H. Acute pesticide poisoning among female and male cotton growers in India. Int J Occupational Environ Health. 2005; 11: 221-232

11. Remor AP, Totti CC, Moreira DA, Dutra GP, Heuser VD, Boeira JM. Occupational exposure of farm workers to pesticides: biochemical parameters and evaluation of genotoxicity. Environ Int. 2009; 35: 273-278.

12. Wesseling C, Aragón A, Castillo L, Corriols M, Chaverri F, Cruz EDL, et al. Hazardous pesticides in Central America. Int J Occupational Environ Health. 2001; 7: 287-294.

13. Zacharia JT. Identity, physical and chemical properties of pesticides. Pesticides in the Modern World-Trends in Pesticides Analysis. 2011; 21: 1-8.

14. Leshniowsky WO, Dugan PR, Pfister RM, Frea JI, Randles CI. Aldrin: removal from lake water by flocculent bacteria. Sci. 1970; 169: 993-995.

15. Honeycutt M, Shirley S. Aldrin. Encyclopedia of Toxicol. 2014; 1: 126-129.

16. Environmental Protection Agency (EPA). DDT – a brief history and status. Washington (DC): EPA; 2012.

17. Beard J, Australian Rural Health Research Collaboration. DDT and human health. Sci Total Environ. 2006; 15: 78-89.

18. World Health Organization. Agrochemicals, health and environment: directory of resources. WHO; 2017.

19. Pretty J, Hine R. Pesticide use and the environment. Pesticide Detox. 2012; 23: 23-44

20. Centers for Disease Control and Prevention. Dichlorodiphenyltrichloroethane (DDT) factsheet. Atlanta (GA): CDC; 2021.

21. Kimbrough RD. Polychlorinated biphenyls (PCBs) and human health: an update. Crit Rev Toxicol.1995; 25: 133-163.

22. Faroon OM, Keith SL, Smith-Simon C, De Rosa CT. Polychlorinated biphenyls: human health aspects. World Health Organization. 2003.

23. Carpenter DO. Polychlorinated biphenyls (PCBs): routes of exposure and effects on human health. Rev Environ Health 2006; 21: 1-23.

24. Teague CE. Research planning memorandum on some thoughts about new brands of cigarettes for the youth market. RJR Tobacco Company, 1973; 505101981-1992.

25. Centers for Disease Control and Prevention (US), National Center for Chronic Disease Prevention and Health Promotion (US), Office on Smoking and Health (US). How tobacco smoke causes disease: the biology and behavioral basis for smoking-attributable disease: a report of the Surgeon General. Atlanta (GA): Centers for Disease Control and Prevention (US); 2010.

26. Chen X, Zhang F, Yao H, Wang J, Qi D, Guo Y. Analyzing multiple pesticides in tobacco leaf using gas chromatography with quadrupole time-of-flight mass spectrometry. J Separation Sci. 2018; 4: 1983-1989.

27. Rodgman A, Perfetti TA. The chemical components of tobacco and tobacco smoke. CRC Press. 2008; 1840.

28. Carvalho FP. Pesticides, environment, and food safety. Food Energy Security. 2017; 6: 48-60.

29. Talhout R, Schulz T, Florek E, Van Benthem J, Wester P, Opperhuizen A. Hazardous compounds in tobacco smoke. Int J Environ Res Public Health. 2011; 8: 613-628.