Maximum Tolerable Limit Research Articles

Characterization and risk assessment of arsenic contamination in soil-plant (vegetable) system and its mitigation through water harvesting and organic amendment.

Field experiments with vegetables [cauliflower (Brassica oleracea var. botrytis), tomato (Solanum lycopersicum) and spinach (Spinacia oleracea)] were conducted at geogenically arsenic-contaminated Ghentugachi village in West Bengal, India, for two consecutive years to study arsenic accumulation by the selected vegetables and to explore the efficiencies of use of harvested/harnessed water and organic amendments (Mustard Cake, Vermicompost and Farm Yard Manure) in reducing arsenic load in soil-plant system. Results revealed that arsenic accumulations in the cauliflower head, spinach leaf and tomato fruit were in the range of 0.15-0.17, 2.73-3.00 and 0.08mgkg-1. Organic amendment and pond water irrigation when applied either separately or together were found to be effective in reducing arsenic contamination in soil-plant system compared to irrigation with shallow tube well-drafted underground water. Vermicompost remained most successful among the organic amendments. Conjunctive use of surface (pond) and ground water also significantly reduced the level of arsenic in the system. The risk of dietary intake of arsenic through the selected vegetables was computed through % Provisional Tolerable Weekly Intake, Hazard Quotient and Target Cancer Risk. Cauliflower and tomato were found safe in the individual contribution to food chain, while consumption of spinach leaf (possessing 10.4-22.6% more arsenic than maximum tolerable limits) remained unsafe in all dietary risk measures.

Effect of oxygen containing compounds in uranium tetrafluoride on its non-adiabatic calciothermic reduction characteristics

Uranium ingot is produced by metallothermic reduction of uranium tetrafluoride using magnesium or calcium as reductant. Presence of oxygen containing compounds viz. uranyl fluoride and uranium oxide in the starting uranium fluoride has a significant effect on the firing time, final temperature of the charge, slag-metal separation and hence the metal recovery. As reported in the literature, the maximum tolerable limit for uranyl fluoride in the UF4 is 2.5 wt% and limit for uranium oxide content is in the range 2–3 wt%. No theoretical or experimental basis is available till date for these limits. Analyses have been carried out in this study to understand the effect of UO2F2 concentration in the starting fluoride on the final temperature of the products and thus the reduction characteristics. UF4 having uranyl fluoride concentration, less than as well as more than 2.5 wt%, have been investigated. Thermodynamic calculations have been carried out to arrive at a general expression for the final temperature attained by the products during calciothermic reduction of UF4. Finally, an upper limit for the oxygen containing impurities has been estimated using the CaO–CaF2 phase diagram.

Innate Immune Response and Growth Performance of Heterobranchus longifilis Catfish Juveniles Following Dietary Aflatoxin B1 Exposure

We evaluated the effects of dietary aflatoxin B1 (AFB ) exposure on the immune response and the 1 growth performance of Heterobranchus longifilis catfish; and determined the maximum tolerable limits for AFB in H. longifilis. Five experimental isocaloric and isonitrogenous diets amended 1 with varied concentrations of AFB [Diet A (2.0 μg AFB .kg-1); Diet B (7.3 μg AFB .kg-1); Diet C 1 1 1 (17.6 μg AFB .kg-1); Diet D (48.0 μg AFB .kg-1) and Diet E (93.0 μg AFB .kg-1)] were fed to 450 1 1 1 juvenile H. longifilis in five groups of 15 separate plastic tanks for a period or 56 days. At time points day 7, 14, 28 and day 56, five fish were randomly sampled per tank and assessed for innate immunity and growth response. Fish fed diets amended with AFB exhibited significant reduction 1 (P < 0.05) in the serum lysozyme and epidermal mucus lysozyme activity, epidermal mucus alkaline phosphatase activity and in the phagocyte respiratory burst activity. These parameters decreased with increasing concentrations and duration of dietary AFB (P< 0.05). Dietary AFB 1 1 caused significant reductions in the growth performance of juvenile H. longifilis marked by reductions in the percentage gain in length, reduction in percentage gain in weight and a reduction in the specific growth rate. Based on these results, juvenile H. longifilis catfish appears to tolerate diets containing up to 17.6 μg. Kg-1 AFB in diets.

Determination of Ochratoxin A and Ochratoxin B in Archived Tokaj Wines (Vintage 1959-2017) Using On-Line Solid Phase Extraction Coupled to Liquid Chromatography.

According to the EU legislation, ochratoxin A contamination is controlled in wines. Tokaj wine is a special type of sweet wine produced from botrytized grapes infected by “noble rot” Botrytis cinerea. Although a high contamination was reported in sweet wines and noble rot grapes could be susceptible to coinfection with other fungi, including ochratoxigenic species, no screening of Tokaj wines for mycotoxin contamination has been carried out so far. Therefore, we developed an analytical method for the determination of ochratoxin A (OTA) and ochratoxin B (OTB) involving online SPE coupled to HPLC-FD using column switching to achieve the fast and sensitive control of mycotoxin contamination. The method was validated with recoveries ranging from 91.6% to 99.1% with an RSD less than 2%. The limits of quantification were 0.1 and 0.2 µg L−1 for OTA and OTB, respectively. The total analysis time of the online SPE-HPLC-FD method was a mere 6 min. This high throughput enables routine analysis. Finally, we carried out an extensive investigation of the ochratoxin contamination in 59 Slovak Tokaj wines of 1959–2017 vintage. Only a few positives were detected. The OTA content in most of the checked wines did not exceed the EU maximum tolerable limit of 2 µg L−1, indicating a good quality of winegrowing and storing.

Nutrient concentrations in two savannah grass species and their implications for grazers

The diversity of grazers on savannahs exerts pressure on the grass to provide nutrition. In this study the concentrations of major and trace animal nutrients in above ground grass tissue as influenced by grazing were examined. Two palatable grass species grazed by both livestock and wild grazers were sampled: Brachiaria nigropedata and Eragrostis lehmanniana. Samples of grass tissue were collected from widely spread sampling sites in both livestock and wildlife grazing sites, at the end of the growing season. Although B. nigropedata had higher nutrient concentrations, there was general covariance in nutrient levels in the two grasses. The covariance indicated that the respective sites generally had location context-dependent low or high nutrient concentrations in all grasses. The adequacy of the nutrient concentrations for grazer nutrition was assessed using literature-sourced minimum and maximum tolerable limit requirements of cattle and the high population gazelle-like species as illustration. The results showed that, in these nitrogen-limited savannahs, the grass generally met grazer requirements in terms of crude protein, potassium, molybdenum, nickel and zinc but that it had deficiencies in phosphorous, sodium, and boron, as well as grazing intensity-related localised toxic levels of potassium, phosphorous, magnesium, iron and manganese. The deficiencies and toxicities were inferred to result in abnormalities in grazer physical condition and reproduction. Given the importance of livestock in semiarid savannahs, these effects on livestock grazers were inferred as threatening human food security. The study shows that high grazing intensity can raise the concentrations of some animal nutrients in above ground grass tissue to levels above grazer tolerable limits. Grazing rotation to reduce grazing intensity is recommended as a proactive grazing management strategy to limit the effects.

Contaminación sonora en la ciudad de Barranca-Lima-Perú

Diversas publicaciones, reportan efectos dañinos por contaminación sonora siendo de importancia médica y social; que provocan en las personas efectos como estrés, ansiedad, problemas cardiovasculares, deterioro cognitivo y disminucion del estado fisico entre otros. El objetivo de la investigación fue monitorear el sonido in situ en la ciudad de Barranca, Lima – Perú e identificar los decibeles al cual estarían sometidos algunas zonas de protección especial y comercial. El registro de sonido se realizó con un sonometro, en los frontis de instituciones educativas, centros de salud, y zonas comerciales. Los resultados mostraron que el nivel sonoro superó el límite máximo tolerable de 50 dB establecido en el Decreto Supremo Nº 085-2003-PCM, en las zonas de protección especial como el Colegio Ventura Ccalamaqui y Hospital de Barranca Cajatambo y zonas mixtas como mercado y centro comercial. En conclusión, la contaminación sonora en las zonas evaluadas en la ciudad de Barranca, supera los límites máximos establecidos, obteniéndose máximos de 79,32±2,07 dB, sobre todo el primer día laborable en inicio de semana; los altos niveles sonoros provocarían consecuencias negativas en la salud.

Electric field-induced band modulation of predicted ternary 2D MXC3 [M:X = As:Ge, Sb:Sn and Bi:Pb] with strong stability and optical properties

The present work reports a new series of ternary two-dimensional MXC3 [M:X = As: Ge, Sb: Sn and Bi: Pb] compounds whose stability and existence are confirmed through the phonon dispersion analysis, elastic properties and ab initio molecular dynamics simulation. The developed compounds are further investigated with their electronic and optical properties using density functional theory. We have observed zero bandgap nature in MXC3 compounds, where AsGeC3 shows the graphene-like band structure with Dirac cone at K-point. We have systematically applied the external electric field up to ±0.40 eV/Å to modulate the electronic and optical properties of these compounds. The increasing magnitude of the electric field has shown the increasing nature of bandgap in the AsGeC3 compound, while no effect was observed in case of SbSnC3 and BiPbC3 compounds. Consequently, the bandgap of AsGeC3 compound is tuned up to 0.98 eV which is maximum at an optimum value of the applied electric field of ±0.40 eV/Å. All the three 2D MXC3 compounds have shown the broken symmetry of the structure after the optimum value of the electrical field that can be understood by the maximum tolerance limit of an applied electric field. Our results strongly suggest the excellent mechanical stability of the AsGeC3 compound under the applied electric field. We have also calculated the variation in the optical properties upon the external field for the AsGeC3 compound, which shows a good transparency nature and can be used in the regulation of the smart window applications. We sincerely believe that our outcomes reflect a significant achievement for potential applications in future nanoelectronics and optoelectronic devices along with tunable electronic properties.

Effects of High-Dose of Copper Amino Acid Complex on Laying Performance, Hematological and Biochemical Parameters, Organ Index, and Histopathology in Laying Hens.

The objective of the study was to evaluate the maximum tolerance limit of amino acid copper complex (Cu-Lys-Glu) for laying hens by measuring their laying performance, hematological and serum biochemical parameters, organ index, and histopathology. A total of 450 18-week-old Beijing White layers were randomly allocated to 5 groups (90 birds per group) with 6 replicates of 15 birds each. After a 2-week acclimation on a basal diet (analyzed copper content 8.63mg/kg), the birds were fed diets supplemented with 0 (control), 15, 75, 150, and 300mg Cu/kg as Cu-Lys-Glu for 10weeks. Results showed that, compared with the control group, dietary supplementation with 15, 75, and 150mg Cu/kg as Cu-Lys-Glu did not affect (P > 0.05) laying performance, whereas hens receiving with 300mg Cu/kg significantly decreased (P < 0.001) the laying rate as compared with the control. No significant differences (P > 0.05) were observed among the hens receiving 0, 15, 75, and 150mg Cu/kg as Cu-Lys-Glu in hematological and serum biochemical parameters, organ indexes, and histopathological changes. However, hens receiving 300mg Cu/kg significantly increased (P < 0.05) the concentrations of mean corpuscular volume (MCV), albumin (ALB), total bilirubin (TBILI), alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea nitrogen (UN), and creatinine (CRE), as well as caused severe microscopic histopathological changes in the liver and kidney. In conclusion, 150mg Cu/kg as Cu-Lys-Glu is identified as no-side-effect supplementation level in laying hens after daily administration for 70days.

Fungal Diversity and Evaluation of Ochratoxin A Content of Coffee from Three Cameroonian Regions

The present study had the objective to assess the ochratoxin A content of coffee through chromatographic analysis and design a method using PCR-DGGE to analyze at the same moment the totality of fungal flora present in the coffee samples in order to determine their geographic origin. 96 samples of coffee were collected from the west region (Bafoussam and Dschang), centre region (Bafia), and east region (Batouri) of Cameroon during two years (2017 and 2018). Two treatments (dry and wet routes) were evaluated at three different steps of coffee processing (parchment coffee, green coffee, and husk coffee). The characterization of the fungal profile was done with PCR-DGGE and sequencing. The levels of OTA were assessed using HPLC analysis. The results indicated that the toxinogenic mycoflora associated with coffee beans was mainly Aspergillus niger, A. carbonarius, and A. ochraceus. PCR-DGGE data revealed that each sampling site is characterized by a specific fungal profile. Despite the influence of the treatment on the fungal population of coffee, bands common to samples coming from the same site were observed. These bands could therefore constitute potential biological markers to trace back to the origin of coffee. OTA was detected in most of the coffee samples analyzed and only few samples contented OTA at levels higher than the maximum tolerable limit for food intended for human consumption. The OTA content of coffee was significantly influenced by the sampling step and the sampling period.

Residues of antibiotics in raw honeys from different apiaries of Northern India and evaluation of human health risks

Indiscriminate use of antibiotics in apicultural practices may lead to contamination of otherwise healthy and naturally produced honey. Contamination not only affects honey quality but also pose significant health risks to consumers. In this context, one hundred raw honey samples from India were analysed for presence of antibiotic residues. For determination of oxytetracycline and erythromycin, high performance liquid chromatography and for chloramphenicol, enzyme immunoassay based validated procedures were used. Oxytetracycline and erythromycin with concentrations above maximum tolerance limits were detected in 24% and 2% samples, respectively. None of the samples contained chloramphenicol residues. Although, total dietary intake of detected antibiotics through honey was found to be &lt;1% of their acceptable daily intake values, the presence of antibiotics in honey is an alarming health concern for people following customary honey feeding. The outcomes underline the need of inter-sectoral approaches to create awareness among beekeepers regarding health risks associated with residues of antibiotics in honey and merits of approved apicultural practices. Therefore, to meet global food safety requirements, continual residue monitoring schemes along with enlightenment of beekeepers on scientific beehive management and risks associated with incautious apicultural practices are of vital importance.

The Occurrence and Risk Assessment of Aflatoxin M1 in Yoghurt Samples from Hamadan, Iran

Background: Aflatoxin M1 (AFM1) is a hepatocarcinogenic and hydroxylated metabolite of aflatoxin B1, detected in milk and milk products. Objectives: The aim of our research was to determine the incidence and risk assessment of AFM1 through the consumption of yoghurt in Hamadan province of Iran. Methods: Fifty yoghurt samples were gathered from various areas of Hamadan province, Iran and tested for AFM1 by ELISA technique. The estimated daily intake (EDI) and the liver cancer incidence of aflatoxin M1 were determined. Results: AFM1 was detected in 43 (86%) samples, (mean: 28.56 ng/kg; range: &lt;5-98.65 ng/kg). The level of AFM1 in 9 (18%) samples was above the maximum tolerance limit (50 ng/kg). The AFM1 intake through yoghurt consumption in various population groups ranged from 0.016 to 0.032 ng/kg bw/day in mean consumers and 0.019 to 0.046 ng/kg bw/day in high consumers. Conclusion: The AFM1 intake through yoghurt contributed a slight part from the overall incidence of liver cancer in the Iranian population. From the findings of the current study, it can be derived that although the high percentage of yoghurt samples in Iran proved to be contaminated with AFM1 contents, did not show a public health concern considering the European Commission (EC) and the Institute of Standards and Industrial Research of Iran (ISIRI) maximum limits.

Sustainable conversion of palm juice wastewater into extracellular polysaccharides for absorption of heavy metals from Saudi Arabian wastewater

The main aim of the study was to use palm juice wastewater as an alternative feedstock for the production of extracellular polysaccharide and to remove heavy metals from the wastewater. Heavy metal resistant bacteria were screened from soil sediment samples, and metal resistant properties were analysed. A total of five bacterial strains were selected for the analysis of maximum tolerance limit against five toxic heavy metals (Cu2+, Cd2+, Pb2+, Co2+ and Zn2+). Among the five bacterial strains, Pseudomonas aeruginosa Al-Dhabi144 showed resistance against Cu2+, Cd2+, Pb2+, Cu2+ and Zn2+ and maximum tolerance limit was 400, 350, 2000, 100 and 350 mg/L, respectively. Wastewater was used as the feedstock for the production of extracellular polysaccharide in submerged fermentation. Extracellular polysaccharide production was enhanced after 72 h incubation (4.8 ± 0.37 g/L), 1.5% inoculums (4.96 ± 0.15 g/L), 10% date syrup wastewater (8.3 ± 0.041 g/L), pH 7.5 (7.9 ± 0.059 g/L), 0.5% yeast extract (8.1 ± 0.074 g/L) and 0.5% starch (9.74 ± 0.036 g/L). The metal-absorption properties of extracellular polysaccharides revealed that P. aeruginosa Al-Dhabi144 extracellular polysaccharides had the ability to remove Cu2+ (300 ± 5.3 mg/g), Cd2+ (250 ± 10.4 mg/g), Pb2+ (380 ± 5.1 mg/g), Co2+ (225 ± 5.6 mg/g) and Zn2+ (250 ± 10.7 mg/g) from the wastewater.

Impact Assessment of Smoking Duration on Polycyclic Aromatic Hydrocarbons (PAH’s) Contaminations of Clarias gariepinus

Smoked catfish (Clarias gariepinus) was examined with the aim of determining the effect of smoking duration on the extent of accumulation of the sixteen US EPA priority polycyclic aromatic hydrocarbons (PAHs). The levels of PAHs in the smoked catfish samples were obtained using gas chromatography with a flame ionization detector after extracting with nhexane by soxhlet extraction technique. The result showed detection of all the 16 PAHs in the smoked catfish. Higher molecular weight PAHs having ≥4 rings showed considerably higher concentration as compared to PAHs that had a lower ring. The mean concentrations of total PAH in the investigated smoked catfish showed mean values of 1.91 μg/kg, 2.10 μg/kg, 2.32 μg/kg, 2.58 μg/kg respectively. The ΣBaPeq (0.113) and ΣPAH (10.642 μg/kg) levels are within the range of European Commission Regulations maximum tolerable limits of 2 to 5 μg/kg respectively. The result indicated that the PAH accumulation is directly proportional to the smoking period. Diagnostic ratio (Ant/(Ant+Phen) ratio &lt;0.10) conducted showed wood combustion as the main sources of contamination in the analyzed smoked catfish.

Effects of Effluents on the Quality of River Rido, Kaduna- State, Nigeria

This study examines the effect of discharged effluents on the quality of river Rido in Kaduna. Ten water samples were collected and tested for Arsenic (As), Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Lead (Pb), Manganese (Mn), Mercury (Hg), Nickel (Ni) and Zinc (Zn). The results revealed that in the dry season, six heavy metals, namely As, Cd, Cu, Mn, Ni and Zn, presented mean values that were higher after the point of effluent discharge; while Cr, Fe and Pb had lower values and Hg was not detected. In the wet season all the heavy metals tested, except Hg, increased in values after the point of effluent discharge. The values of As, Cd, Fe, Mn, Ni and Pb after the discharge point, in dry and wet seasons, were greater than the maximum tolerable limits set by the Standard Organisation of Nigeria (SON) and the World Health Organisation (WHO). The values recorded for Zn and Cu at both dry and wet seasons were below the limit set by the Standard Organisation of Nigeria (SON) and the World Health Organisation (WHO), but the value of Cr was lower than the maximum tolerable limit only in the dry season. The contamination of the river with heavy metals poses a grave danger to human health, as its water is used for diverse purposes. The wastewater treatment plant of KRPC should be rehabilitated and the wastewater can be pre-treated before it is discharged into the river.

Total aflatoxin, aflatoxin B1 and ochratoxin a levels in Turkish wheat flour

This study was designed to assess the total aflatoxin (total AF), aflatoxin B1 (AFB1) and ochratoxin A (OTA) levels in 100 samples of wheat flour obtained from 7 different producing regions of Thrace by the microtitre plate enzyme-linked immunosorbent assay (ELISA). According to the EC Regulation and the Turkish Food Codex, the total AF, AFB1 and OTA levels were between minimum detection limit (0.05, <1.0, 0.025 μg/kg) and the maximum tolerable limit (4, 2, 3 μg/kg) in 43, 18 and 53 samples, respectively. Whilst 2, 2 and 28 samples had unacceptable contamination levels higher than the maximum tolerable limits, respectively. This is the first study in Thrace, Turkey on account of OTA, and the presence of OTA in 81% of analysed samples and taking part in South-Eastern Europe of sampling area would be indirectly related to Balkan Endemic Nephropathy and also be of risk to public healthy.

Aflatoxin in raw peanut kernels marketed in Malaysia

The occurrence of aflatoxin in eighty-four samples of raw peanut kernels which are randomly collected from Malaysian supermarkets was examined. Analysis for aflatoxin was performed by solvent extraction and immunoaffinity clean-up followed by the determination using high performance liquid chromatography equipped with post-column photochemical reactor for enhanced detection and fluorescence detector. A detection limit of 0.01-0.09 ng/mL and a quantification limit of 0.04-0.30 ng/mL were obtained. The aflatoxin concentrations ranged from not detected to 97.28 ng/g in all samples investigated. About 78.57% of the samples were contaminated with aflatoxin, of which 10.71% exceeded the maximum tolerable limit of 15 ng/g set by the Codex. Average recoveries of the aflatoxin analysis were acceptable which were in the range of 74.85 ± 8.83% for AFG2 at the concentration of 0.15 ng/mL and 103.91 ± 6.45% for AFB2 at the concentration of 0.15 ng/mL. The average daily intake estimated for total aflatoxins was 10.69 ng/kg body weight. There was a significant difference (P < 0.05) in aflatoxin content between brands and locations.

Simultaneous determination of sulfa drugs and tetracyclines in feeds and animal tissues by high-performance liquid chromatography

This study aimed to develop a high-performance liquid chromatographic method for simultaneous determination of six sulfa drugs, three tetracyclines antibiotics and carbadox in feeds and animal tissues. Four successful conditions were established: 1. On LiChrosorb RP-C18 column with water: acetonitrile (95:5, v/v) s mobile phase and UV detector at 254 nm to separate SDA, SMM, STA, SDM, SMT and SQO. 2. On ultrasphere ODS Column with water: acetonitrile (85:15, v/v) as mobile phase and detected at UV 254 nm to separate SDA, SMM, STA, SMT, SQO and SDM. 3. On LiChrosorb RP-C18 column with water: isopropanol (93:7, v/v) as mobile phase and detected at UV 254 nm to separate STA, SMT, Carbadox, TC, OTC and CTC. 4. On Alltech RP-C18 column with water: dimethylformamide (72:28, v/v) as mobile phase and detected at UV 280 nm to separate STA, SMT, OTC, Carbadox and CTC. The recoveries of the drugs in feeds were between 85-99%; in animal tissues, 69-80%. Eleven out of 20 feed samples were found with prohibited sulfa drugs or tetracyclines added. One pork sample with OTC residue and two pig liver samples with total sulfa drugs residue exceeding the maximum tolerance limits were detected from the 21 meat samples analyzed. The lowest detection limits of residual drugs were between 1.0 - 5.0 ppb in feeds; 2.0 - 12 ppb in animal tissues.

Aflatoxin M1 levels of skim milk powders produced in Turkey

In this study AFM1 levels of skim milk powders produced in Turkey were determined by immunoaffinity column and HPLC and the results were compared with the values accepted by Turkish Aliment Codex. AFM1 levels of 21 skim milk powder samples collected from seven firms in four different seasons (March-April-May, June-July-August, September-October-November and December-January-February) ranged between 0 to 0.705 μg/kg. Two samples (0.535 and 0.705 μg/kg) had exceeded the tolerance limit accepted by Turkish Aliment Codex (0.5 μg/kg). It was also recorded that these two samples collected in the second season (June-July-August) had no M1 content. From the point of seasonal variation, it was realized that AFM1 contents of the samples collected in summer were lower than that of the samples collected in the winter. Seasonal variations with regard to AFM1 were statistically significant (p < 0.01). As a result, AFM1 levels in 90.5% of the samples provided throughout the year did not exceed the maximum tolerance limit established by Turkish Aliment Codex.

Unusual pattern of aflatoxins and ochratoxin in commercially grown maize varieties of Pakistan

The contamination of food with mycotoxins could be a major health risk. Identification and quantification of mycotoxins in maize are essentially required to guarantee food safety. Seven commonly grown maize cultivars were sown at semi-arid conditions in Pakistan. After harvesting plants, total aflatoxin (AFs), aflatoxins B1 (AFB1), B2 (AFB2), G1 (AFG1), G2 (AFG2), and ochratoxin-A (OTA) contents were determined in maize flour using high performance liquid chromatography (HPLC). Results showed an unusual pattern of AFs in maize with a higher concentration of AFG1 in all maize varieties. The AFB1 was not found in most of the samples, however, all maize grains contained AFs above the maximum tolerable limit (20 μg/kg). The highest concentration of AFs was recorded in Ayub-1/26 maize (362.8 μg/kg). Ochratoxin-A (OTA) was detected in 71% maize samples ranged from 2.14 to 214 μg/kg. The highest OTA and microbial load were recorded in Ayub-2/27 grains that exceeded the FDA limit (50 μg/kg). These results indicated the higher prevalence of total AFs, AFG1, and OTA at the harvest stage of maize that could pose significant health hazards to humans and livestock.

Aflatoxin Contamination of Milk Produced in Peri-urban Farms of Pakistan: Prevalence and Contributory Factors.

Aflatoxin M1 contamination of milk in Pakistan, like many developing countries, is poorly understood. The present study was therefore conducted to determine AFM1 contamination of milk and its contributory factors in Pakistan. We sampled milk and feedstuffs from 450 peri-urban dairy farms in seven major cities following a cross-sectional study design. Analysis of milk using ELISA revealed high contamination with an overall average of 3164.5 ng of AFM1/L, and significant differences (p < 0.001) between cities. The milk sampled from Gilgit, in northern hilly areas, had an average AFM1 level of 92.5 ng/L. Milk from other cities had 3529.7 ng/L average contamination, with only 5.7% samples qualifying the maximum tolerable limit of 500 ng of AFM1/L. Heavy mean aflatoxin contamination was found in bakery waste (724.6 μg/kg), and cottonseed cake (600.8 μg/kg). Rest of the other feedstuffs had moderate to low mean aflatoxin contamination, ranging from 66.0 μg/kg in maize stover to 3.4 μg/kg in wheat bran. The mean aflatoxin level in commercial dairy concentrates was 32.7 µg/kg. About 80% of the total aflatoxin intake of dairy animals was contributed by cottonseed cake alone due to its high aflatoxin contamination and proportion in dairy rations. On-farm storage time of oilseed cakes varied (p < 0.01) in different cities but was not associated with aflatoxin contamination. The exceptionally high AFM1 contamination suggests that milk from peri-urban dairy farms is a serious public health threat in Pakistan. This situation can be mitigated by reducing aflatoxin contamination in cottonseed cake and promoting the use of commercial concentrates and other feedstuffs with low contamination.