Table II.

Summary of studies based on the exposure and outcome

Sl. no.	Study ID	Sample size with subgroup	Exposure assessment	Outcome assessment	Salient finding	Conclusion
			Sample tested & method of testing	Health outcome & method of assessment
1	Ali et al23, 2024	76; E-51 (Rice, wheat, maize. mills workers), NE-25 [rickshaw pullers, housewives, teachers, and businessmen]	Urine AFM1 levels using ELISA	Urine(creatinine) using Biodiagnostic kits	The AFM1 in mill workers’ urine was slightly lower than that of the control group, whilst the AFM1 urinary level adjusted for creatinine was higher in mill workers than in the control group. There was no significant difference in the mean level of urinary creatinine between the mill workers &the control group	The study concluded that in specific occupational setting, there was no extra/additional exposure occurred to workers. However, the presence of non-negligible AFM1 levels in both worker &control group necessitates further biomonitoring studies to explore aflatoxin exposure.
2	Gichohi-Wainaina et al28, 2023	250(rural farming households with children less than 24 months)	Food samples (maize, sorghum, cassava, groundnut, bambara nut) using ELISA[AFB1]	Weight for height Z-score, weight for age Z-score using anthropometric measurements	AFB1 concentration was associated with lower Weight for height Z scores and weight for age Z scores the highest maximum AFB1 contamination levels from all samples obtained were in maize grain. Mean Aflatoxin levels in Maize grain were 156.5 micrograms per Kg.	Aflatoxin exposure in surveyed population was much higher than previous observations made in Tanzania. As high level of contamination was observed, strategies from health, trade and nutrition sector should be designed and implemented to reduce exposure.
3	Karamkhani et al12, 2022	60; E-30 (wet waste processing workers), NE-30 (administrative staff)	Personal and area dust samples and blood samples for AFB1 using High Performance Liquid Chromatography- fluorescence detector (HPLC-FLD).	AFB1/Albumin, LFT, RFT, lipid profile ,antioxidant profile using Biodiagnostic kits	Significant differences between worker &control groups in the biochemical profile tests, (liver and kidney) was observed. On the other hand, the serum triglyceride and total cholesterol concentrations did not show any significant difference. AFB1 exposure caused a significant decrease in the antioxidant capacity. Level of aflatoxin in environment in Spring season was 0.07ng/m3.	The detection of AFB1 in the airborne and settled dust and AFB1-ALB in the serum provide evidence that workers are occupationally exposed to aflatoxin
4	Asri et al8, 2020	124, E-76; rice millers, NE -48; office workers	Dermal wipe sample, personal and area samples for AFB1 using ELISA	Lung function test using spirometry	There was a significant difference in mean FEV1 for pre and post shifts between rice millers and non-exposed group the mean contamination level of AFB1 on hands was 0.25 ng/ml detected on two rice millers (2.3%) while non-detectable in non-exposed workers. However, no correlation was observed between AFB1 levels and lung function tests. Mean levels of Aflatoxin in environment surface area t is 2.22 ng/m3.	Prolonged Exposure to AFB1 may lead to serious Respiratory health effects. Control measures such as hygiene Practices and wearing suitable personal Protective equipment (PPE) are highly recommended in preventing further exposure and to reduce the levels of AFB1 among the Workers.
5	Karamkhani et al20, 2020	40; E-20 [Solid waste processing workers], NE-20 [administrative staff]	Environmental sampling (PET bottle, cardboard and carton, metal and plastic), blood samples using HPLC-FLD	AFB1/Albumin, LFT, RFT, lipid status, antioxidant status and MDA using biodiagnostic kits	Significant difference in the LFT and RFT levels were observed between exposed and unexposed workers. However, no difference was noted in serum triglyceride and total cholesterol concentration. There was a significant reduction in blood antioxidant capacity	The solid waste handlers may be exposed to hazardous levels of Aflatoxin B1. Adverse effects on renal and hepatic system could be due to changes in redox system
6	Saad-Hussein et al29, 2021	166; E-88 [furniture workers], NE-78 [not exposed to wood dust in their occupation]	Blood samples using ELISA Environmental sampling (furniture wood)	Liver enzymes and oxidative markers using biodiagnostic kits	Mean duration of exposure was 17±5.3 years. AFB1/ALB, AST, and ALT were significantly higher in furniture workers compared to controls. MDA and GPX levels showed significant elevation in workers compared with controls. While CAT levels show significantly reduced levels in workers compared with controls. Level of Aflatoxin in environment is given in the range of 9200-3500CFU/m3.	Wood dust exposure is associated with raised serum levels of AFB1 and oxidative stress.
7	Saad-Hussein et al25, 2016	290; E-190 [90 bakers, 100 flour milling workers], NE-100 [not occupationally exposed to wheat dust]	Environmental samples and blood samples using ELISA	Clinical examination, liver enzymes using biodiagnostic kits	The concentration of Aspergillus flavus and Aspergillus niger were higher in bakeries than in the flour mill sections. The serum AFB1-ALB adduct and alp levels were significantly higher in bakers compared to milling workers. The liver enzymes AST and ALT were significantly higher in milling workers and bakers than controls	Chronic occupational exposure to high concentrations of aspergillus in workplaces may cause elevations in serum levels of AFB1 and liver enzymes in workers exposed to flour dust. Hence, worker protection measures should be consistently adopted and enforced at the workplace
8	Saad-Hussein et al21, 2016	375; E-219[132 -flour workers; 81 wheat mill and 51 bakery workers, 87 sawmill workers], NE-156 [workers not occupationally exposed to organic dust]	Blood samples using ELISA, Questionnaire,	Liver enzymes using biodiagnostic kits, PCR	Years of exposure varied between groups. Flour workers: 15±5.2years exposure; Sawmill workers: 17±5.3years exposure. AFB1/ALB and liver enzymes were significantly elevated in exposed workers compared to controls, and were significantly higher in sawmill workers compared to flour workers.	Organic dust exposure may cause elevation in AFB1/ALB and liver enzymes of exposed workers, and GST gene polymorphism plays an important role in susceptibility to hepatic parenchymal cell injury
9	Malik et al11, 2014	90, E- 46 food grain workers/farmer, NE-44	BAL, Blood samples for AFB1 using ELISA, LPCB and SDA culture	Respiratory symptoms, questionnaire	Aflatoxins were detected in 32.6% of food grain workers and 9.1% of non-food grain workers. Significant difference was observed in BAL culture for Aspergillus flavus between exposed and non-exposed. Higher percentage of food grain workers reported respiratory symptoms compared to other group.	Occupational exposure to aflatoxins in food-grain workers was found to be associated with the increased presence of respiratory symptoms
10	Lai et al22, 2014	Ca – workers in sugar and paper making factory with HCC-68, C-Workers without HCC 150. E-181 workshop employees and NE-203 who worked outside the workshop	Environmental dust using ELISA, Serum AFB1 albumin adducts were detected using a double antibody sandwich ELISA	Data on HCC Diagnosis from records	AFB1 was detected in 56.35% of samples among cases and 5.9% in control group respectively. Workers with contaminated dust exposure had higher risk of HCC compared to controls (OR-5.24,95%CI-2.77-9.88). Level of Aflatoxin in environment sample is 8 mcg/kg.	The findings indicate that occupational AFB1 airway exposure might be associated with the risk of AFB1-related HCC among this study population
11	Saad-Hussein et al26, 2014	286; E-190 [100 flourmill workers, 90 bakers], NE-96 [64 healthy subjects from the national research centre, 32 HCC positive controls from the national cancer institute]	Blood sample for AFB1 Albumin using ELISA	Plasma biomarkers using ELISA, colorimetric assay using kits [AFP, AFU, Arginase]	Bakers had significantly higher levels of AFB1/ALB and AFU than the flourmill workers. There is significant elevation in the serum AFB1/ALB of bakers and flourmill workers compared to the normal controls. The AFB1 levels is found to be highest among HCC cases. Similarly, AFP and AFU were all significantly higher and arginase was lower in HCC cases compared to the other groups.	Wheat handlers exposed to high concentrations of Aspergillus flavus have a high risk of developing elevated serum AFB1/ALB and elevated AFU, suggesting that they are at high risk of developing HCC
12	Saad-Hussein et al33, 2014	75; Ca-35 [wheat flour workers with high AFB1-Albumin adduct serum levels], C-40 [healthy males not occupationally exposed to wheat flour dust]	Blood sample for AFB1 Albumin using ELISA	Liver enzymes, P53, GST, SOD, ZINC and vitamin C using biodiagnostic kits	Mean duration of exposure was 22.4±10.6 years. The levels of AFB1, liver enzymes and serum P53 of the workers were significantly elevated compared to the control group. GST, MDA and SOD were significantly increased in the workers compared to the controls group, while antioxidants, vitamin C and levels of Zn in the workers were significantly decreased compared to the controls.	Oxidative stress of AFB1 elevated the MDA and Liver enzymes in wheat milling workers.
13	Saad‐Hussein et al24, 2013	122; E-58 [textile workers from the pre spinning, spinning, and weaving departments], NE-64[ administrative staff]	Urine sample for AFMI using HPLC	Skin prick test using ELISA (Aspergillus species), Tumor markers AFP, AFU, IGF-1 using ELISA/biodiagnostic kits	Mean duration of exposure was 12.0 ± 2.4 years. Positive reactants to Aspergillus niger, Aspergillus flavus, and cotton dust were significantly higher in pre-spinning and spinning workers compared to controls. Urinary AFM1 was significantly higher in the pre-spinning, spinning, and weaving groups compared to control. Highly significant increase in levels of serum AFU in textile workers, compared to the control group.	Exposure to fungi had a significant effect on AFM1 measurements and tumour biomarkers
14	Nuntharatanapong et al32, 2001	14, E-10 [group 1 and group 2; animal feed mixers], NE-4, [other employees]	Environmental (contaminated feed dust sample) and personal dust monitoring for AFB1 using ELISA	Plasma biomarkers (LDH, TNF) using ELISA, Electrophoresis	Samples collected from the control group contained lower levels of aflatoxin than the two exposed groups. A difference in LDH activities in plasma was observed between the exposed worker’s controls. LDH1 decreased, whereas the spleen and LDH3 and LDH4, significantly increased in both exposed groups, higher plasma TNF-α levels were also found in both exposed groups, whereas none were detected in controls. Rice bran had 43.9 ng/kg of total aflatoxins, indicating severe contamination. The average aflatoxin values in air samples in exposed areas were 6.25 ng/m3 and 1.55 ng/m3, where as in control area, it was 0.99 ng/m3	The observed change in LDH and TNF levels in plasma may be associated with inhalation of mycotoxin and other contamination in food staff
15	Olsen et al27, 1988	398 cases of cancer among workers of 241 livestock feed processing companies	Assumed occupational exposure via respiratory route	Cancer incidence using records [cancer registry	Elevated risks for liver cancer and cancers of the biliary tract were observed. Increased risks for salivary gland tumours and multiple myeloma were also detected. A decreased risk for lung cancer was observed; despite possible negative confounding due to the smoking, alcohol habits of the employees,	The finding of an elevated risk for liver cancer and cancers of the biliary tract in this population. The increased risks for salivary gland tumours and multiple myeloma may be due to the same exposures. The lung does not seem to be a target organ for the carcinogenic effect of inhaled aflatoxins in humans.
16	Alavanja et al30, 1987]	2649 (Grain millers, including flour millers and animal feed plant workers)	Exposure assessment not mentioned	Cancer incidence using records [cancer registry]	The overall cancer risk was not increased in this group; however, primary liver cancer was significantly elevated for this group (SIR-238)	The processing and storage of agricultural foodstuffs involve occupational exposures, and this may contribute to different patterns of occupational cancer risk depending on location. Further epidemiologic studies to evaluate the relationship between occupational exposures in this industry and cancer risk are needed.
17	Hayes et al31, 1984	138; E-71 [Oil press workers], NE-67 [workers of corn processing plant]	Environment dust monitoring, food residue for AFB1 (method not mentioned)	Mortality due to all causes, CVD and all cancers using records [cancer registry]	250mcg/kg of Aflatoxin was found in environment dust. The residue cakes from peanuts were found to contain concentrations of aflatoxins of about 300-400 mcg/kg. For the entire period of study, the observed mortalities for total-cancer and respiratory cancer were higher than expected in the aflatoxin-exposed group	Aflatoxins in dust may provide potent inflammatory stimulus as well as carcinogenic exposure. Further investigation in this regard is recommended

The table includes the study identification (author and yr), sample size with subgroup details, methods used for exposure assessment, outcome assessment approaches, key salient findings from each study, and the authors’ conclusions. AFB1 ALB, aflatoxin B1-albumin; AFB1, aflatoxin B1; AFM1, aflatoxin M1; AFP, alpha-fetoprotein; AFU, alpha-L-fucosidase; ALP, alkaline phosphate, ALT, aminotransferase; AST, aspartate aminotransferase; Ca, cases, CAT, catalase; C, control; CL, confidence interval; CVD, cardio vascular disease; E, exposure; ELISA, enzyme linked immunosorbent assay; FEV1,forced expiratory volume; GPX, glutathione peroxidase; GSH, glutathione; GST, glutathione S-transferases; HCC, hepatocellular carcinoma; HPLC-FLD, high performance liquid chromatography- fluorescence detector; HPLC, high performance liquid chromatography, IARC, International Agency for Research on Cancer;IGF1, insulin like growth factor; LDH, lactate dehydrogenase; LFT, liver function test; LPCB, direct mount and lactophenol cotton blue; MDA, malondialdehyde; NE, non exposure; NOS, Newcastle-Ottawa Scale; OR, odds ratio; P53,tumorprotein p53;PCR, polymerase chain reaction; RFT, renal function test; PRISMA, Preferred Reporting Items for Systematic Reviews and Meta-Analyses; SDA, Sabouraud’s dextrose agar; SIR, standard incidence ratio; SOD, superoxide dismutase; TAC, total antioxidant capacity; TNF, tumour necrosis factor; Zn, zinc