Evaluating aflatoxins and Sudan dyes contamination in red chili and turmeric and its health impacts on consumer safety of Lahore, Pakistan.

Spices are contaminated with aflatoxins (AFs) and Sudan dyes which are classified as class Group 1 and Group 3 human carcinogens by the International Agency for Research on Cancer (IARC) respectively and their prolonged exposure may raise a human health concern. A total of 474 samples of red chili and turmeric were collected from Lahore city and were subjected to quantitative and qualitative AFs and Sudan dyes analysis by thin layer chromatography (TLC) respectively. The number of red chili and turmeric samples with ≥10 µg/kg of total AFs (European Union standard limit) were 70% and 33% respectively and considered unfit for human consumption. The presence of Sudan dyes in red chili and turmeric samples was 67% and 27% respectively. The mean estimated daily intake (EDI) among females and males was 0.0019 µg/kg bw/day, 0.0012 µg/kg bw/day for red chili, and 0.0008 µg/kg bw/day, 0.0006 µg/kg bw/day for turmeric respectively. The mean value of margin of exposure (MOE) among females and males for ingestion of AFs-contaminated red chili and turmeric was 210.25, 332.13, 501.02, and 699.31 respectively. Therefore, the current study demands a continuous monitoring plan and the implementation of novel techniques to enhance the product's quality and protect public health.

Geochemical distribution and environmental risk assessment of trace metals in groundwater released from e-waste management activities in Lahore, Pakistan.

Non-sustainable e-waste recycling and dumping activities release trace metals into the ambient environment where they may threaten the biological communities and human health. A total of 45 groundwater and 21 leachate samples were collected from seven recycling, seven dumping, and one reference site in Lahore, Pakistan, and analyzed for Cu, Pb, Zn, Cd, Mn, and Fe in atomic absorption spectrophotometer. Comparing the results with the World Health Organization (WHO) standards of drinking water, only the concentrations of Cu, Zn, Mn, and Fe at all sites were found to be within the permissible limits, i.e., 2, 3, 0.5, and 1 mg/L, respectively. In leachates, only Cd and Mn at one site (0.204 and 8.636 mg/L, respectively) exceeded the allowable limits of National Environmental Quality Standards of Municipal and Liquid industrial effluents. Geo-accumulation index, contamination factor, contamination degree, and pollution load index values showed no to moderate contamination. The ecological risk index did not exceed 150, depicting low risk to nearby biological communities. The non-carcinogenic health risk assessment showed a hazard index value greater than 1 at all sites for children (2.04) and adults (1.52), with Pb being the major contributor to adverse health impacts via ingestion and dermal route. Children (1.21 × 10-4) were at a more significant threat of carcinogenic risk from Pb and Cd as compared to adults (8.10 × 10-5). Therefore, there is a dire need to introduce sustainable e-waste recycling and managing techniques to reduce further groundwater contamination via the percolation of trace metals and to reduce the current contamination level.

Evaluation and environmental risk assessment of heavy metals in the soil released from e-waste management activities in Lahore, Pakistan.

In developing regions, electronic waste either gets recycled by using crude and primitive techniques in recycling centers or dumped in dumping grounds that result in the leaching of heavy metals into the ambient environment. The objective of this study is to determine the concentration of heavy metals (Cu, Pb, Zn, Cd, Mn, and Fe) in the surface soil of recycling centers and dumping sites in Lahore, Pakistan, and to quantify and compare the environmental risk. The mean concentration (mg/kg) of Cu, Pb, Zn, and Cd was 722.96, 446.81, 378.76, and 4.11, respectively in the surface soil of recycling centers, and only the mean concentration of Cu (214.09 mg/kg) from dumping sites were above permissible limits of World Health Organization. Results of the geo-accumulation index (Igeo) and contamination factor (Cf) revealed that the surface soil is highly contaminated with Cu, Pb, and Cd. The Cd content (701.24) caused a very high potential ecological risk (Er) (> 320) to nearby biological communities. The noncarcinogenic risk was only expected from Pb to children (1.70) living near recycling centers, whereas no risk was observed for adults living either near recycling centers (0.23) or dumping sites (0.01). There is a high probability of carcinogenic health risks to children (1.085 × 10-2) and adults (1.195 × 10-3) from Cu. Hence, all the results suggest that e-waste recycling and dumping activities were a significant source of heavy metals to the surrounding environment, children, and adults, so it is strongly recommended to take action for sustainable management of e-waste.

Determination and detoxification of aflatoxin and ochratoxin in maize from different regions of Pakistan.

The contamination of food commodities with mycotoxins could be a serious health threat to humans and animals. Therefore, identification, quantification and reduction of mycotoxins in food commodities, particularly of aflatoxins (AFs) and ochratoxin A (OTA) in grain foods, is essentially required to guarantee safe food. This study determined the levels of AFs and OTA in 135 maize grains samples belonging to eight salient maize varieties cultivated in Pakistan, and evaluated the usefulness of radiations and adsorbents to reduce their levels. High performance liquid chromatography (HPLC)-based method was validated for the determination of AFs and OTA in maize grains. The results showed that 69 and 61% samples were positive for AFs and OTA, respectively and 54 and 22% of the respective samples had AFs and OTA above the permissible limits set by Pakistan Standards and Quality Control Authority. The concentration of AFs, AFB1and OTA in grains ranged from 14.5 to 92.4, 1.02 to 2.46 and 1.41 to 53.9 µg kg-1, respectively. Among the varieties, Pearl had the highest level of total AFs and OTA, whereas YH-5427 had the highest AFB1 level. The lowest concentration of AFs and OTA was found in Malaka and 30Y87, respectively. The use of 15 kGy gamma irradiation for 24 h, sunlight-drying for 20 h and UV irradiation for 12 h almost completely degraded the mycotoxins. The microwave heating for 120 s resulted in 9-33% degradation of mycotoxins. Moreover, the treatment of grains' extract with activated charcoal (5% w/w) removed > 96% of total AFs and AFB1, and up to 43% of OTA. The use of bentonite at the same rate removed OTA, total AFs and AFB1 by 93, 73 and 92%, respectively. Thus, it is concluded that contamination of maize grains with mycotoxins was fairly high in the collected maize grain samples in Pakistan, and treatment with radiations and adsorbents can effectively reduce mycotoxins contamination level in maize grains.

Nutritional status, antioxidant activity and total phenolic content of different fruits and vegetables' peels.

The present study assessed nutritional status, antioxidant activity, and total phenolic content in fruits, i.e., mango (Mangifera indica), apple (Malus domestica), and vegetable, i.e., bottle gourd (Lagenaria siceraria), and ridge gourd (Luffa acutangula) peels. The antioxidant activity and total phenolic content (TPC) were evaluated by using methanol extracts along with 2, 2-diphenyl-1-picrylhydrazyl (DPPH), Folin-Ciocalteu (FC) assay, respectively having Butylated hydroxytoluene (BHT) and Gallic acid (GA) as standard. The TPC and antioxidant activity in the peels ranged from 20 mg GAE/g to 525 mg GAE/g and 15.02% to 75.95%, respectively, which revealed that investigated fruit and vegetable peels are rich source of phytochemical constituents. Bottle gourd peels exhibited the highest value of DPPH compared to the rest of the peels included in the study. Likewise, mango peels had the highest TPC as compared to the rest of the fruit peels. This research showed that the utilization of agricultural wastes should be promoted at commercial level to achieve the nutritional benefit at zero cost and minimize the generation of biological waste.

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.

Organochlorine pesticides across the tributaries of River Ravi, Pakistan: Human health risk assessment through dermal exposure, ecological risks, source fingerprints and spatio-temporal distribution.

This study monitored the human health risks through dermal exposure, hazardous risks to ecological integrity, contamination levels, spatio-temporal distribution, and congener specific analysis of organochlorine pesticides (OCPs) across River Ravi and its three northern tributaries (Nullah Bein, Nullah Basanter and Nullah Deg). The residual levels of OCPs isomers were screened for water (n=54) and surface sediment (n=54) samples from twenty seven sampling sites in two alternate seasons (pre-monsoon and post-monsoon). The ∑OCPs concentrations ranged from 13.61 to 1992.18ng/g dry weight and 12.89 to 128.16ng/L with predominance of ß-endosulfan and p,p'-DDT in sediment and water matrixes, respectively. Distribution pattern revealed significantly higher concentrations in upstream and midstream, suggesting considerable transboundary OCPs pollution. Calculated ratios of α-HCH/γ-HCH, o,p'-DDT/p,p'-DDT, (DDE+DDD)/∑DDTs and cis/trans-chlordane for water and sediments identified the fresh addition of lindane, technical DDTs and chlordane in the study area. Risk quotient (RQ) based ecological risk was found to be >1 at all studied streams during both seasons and elucidates higher risks for endosulfan (α-endosulfan) and endrin. Human health risk assessment indicated absence of hazardous (non-carcinogenic) risk through bathing in studied streams; as the hazard index values ranged from 1.09E-05 to 2.48E-02 (acceptable limit; <1). However, the calculated carcinogenic risk possessed by OCPs through dermal exposure ranged from 1.39E-10 to 1.98E-05 that highlighted the considerable carcinogenic risk associated to aldrin, dieldrin, p,p'-DDT and ß-endosulfan at certain studied sites. Therefore, the high levels of ecological risk and carcinogenic human health risk had emphasized an immediate elimination of ongoing OCPs addition in the studied area.

Occurrence, ecological risk assessment, and spatio-temporal variation of polychlorinated biphenyls (PCBs) in water and sediments along River Ravi and its northern tributaries, Pakistan.

Ecological risk assessment, spatio-temporal variation, and source apportionment of polychlorinated biphenyls (PCBs) were studied in surface sediments and water from River Ravi and its three northern tributaries (Nullah Deg, Nullah Basantar, and Nullah Bein) in Pakistan. In total, 35 PCB congeners were analyzed along 27 sampling stations in pre-monsoon and post-monsoon seasons. The ∑35PCB concentration ranged from 1.06 to 95.76 ng/g (dw) in sediments and 1.94 to 11.66 ng/L in water samples, with hexa-CBs and tetra-CBs as most dominant homologs in sediments and water matrixes, respectively. The ∑8DL-PCB levels were 0.33-22.13 ng/g (dw) and 0.16-1.95 ng/L in sediments and water samples, respectively. The WHO-toxic equivalent values were ranged from 1.18 × 10-6 to 0.012 ng/L and 1.8 × 10-6 to 0.031 ng/g in water and sediments matrixes, respectively. The ecological risk assessment indicates considerable potential ecological risk during pre-monsoon season ([Formula: see text] = 95.17) and moderate potential ecological risk during post-monsoon season ([Formula: see text] = 49.11). The industrial and urban releases were recognized as key ongoing sources for high PCB levels in environment. Therefore, we recommend more freshwater ecological studies to be conducted in the study area and firm regulatory initiatives are required to be taken in debt to the Stockholm Convention, 2001 to cop up with PCB contamination on emergency basis.

Degradation of synthetic fragrances by laccase-mediated system.

Laccase mediator systems are important biodegradation agents as the rate of reaction could be enhanced in the presence of redox mediators. In the present study the commercial enzyme laccase from Trametes versicolor and the redox mediator 2,2'-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) were used for the biotransformation of the synthetic fragrances 1-(1,2,3,4,5,6,7,8-octahydro-2,3,8,8,-tetramethyl-2-naphthyl)ethan-1-one (Iso-E-Super, OTNE), 1,3,4,6,7,8,-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyran (Galaxolide, HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphtalene (Tonalide, AHTN) and the transformation product of HHCB, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[g]-2-benzopyran-1-one (Galaxolidone, HHCB-lactone) in water. A particular focus was to assess the effects of the enzyme laccase from Trametes versicolor in the enantioselective degradation of the target compounds, for this reason gas chromatography with an enantioselective column was used as separation technique followed by mass spectrometry detection. In addition, as enantioselective degradation of musk fragrances was observed in wastewater, sewage sludge and fish samples, enantiomeric fractions of selected compounds were studied during composting. In a period of 144h, the target fragrances could be effectively removed by the enzyme laccase with removal percentages greater than 70%, except AHTN with a removal percentage of 42%. However, the degradation process prompted by the enzyme laccase was shown to be non-enantioselective as no significant differences were observer between the enantiomeric fractions calculated at the beginning and at the end of the degradation process. Meanwhile, the composting process was shown to be enantioselective.

Uncertainty in degradation rates for organic micro-pollutants during full-scale sewage sludge composting.

Composting can potentially remove organic pollutants in sewage sludge. When estimating pollutant removal efficiency, knowledge of estimate uncertainty is important for understanding estimate reliability. In this study the uncertainty (coefficient of variation, CV) in pollutant degradation rate (K1) and relative concentration at 35days of composting (C35/C0) was evaluated. This was done based on recently presented pollutant concentration data, measured under full-scale composting conditions using two different sampling methods for a range of organic pollutants commonly found in sewage sludge. Non-parametric statistical procedures were used to estimate CV values for K1 and C35/C0 for individual pollutants. These were then used to compare the two sampling methods with respect to CV and to determine confidence intervals for average CV. Results showed that sampling method is crucial for reducing uncertainty. The results further indicated that it is possible to achieve CV values for both K1 and C35/C0 of about 15%.

Impact of compost process conditions on organic micro pollutant degradation during full scale composting.

Knowledge about the effects of oxygen concentration, nutrient availability and moisture content on removal of organic micro-pollutants during aerobic composting is at present very limited. Impact of oxygen concentration, readily available nitrogen content (NH4(+), NO3(-)), and moisture content on biological transformation of 15 key organic micro-pollutants during composting, was therefore investigated using bench-scale degradation experiments based on non-sterile compost samples, collected at full-scale composting facilities. In addition, the adequacy of bench-scale composting experiments for representing full-scale composting conditions, was investigated using micro-pollutant concentration measurements from both bench- and full-scale composting experiments. Results showed that lack of oxygen generally prevented transformation of organic micro-pollutants. Increasing readily available nitrogen content from about 50 mg N per 100 g compost to about 140 mg N per 100 g compost actually reduced micro-pollutant transformation, while changes in compost moisture content from 50% to 20% by weight, only had minor influence on micro-pollutant transformation. First-order micro-pollutant degradation rates for 13 organic micro-pollutants were calculated using data from both full- and bench-scale experiments. First-order degradation coefficients for both types of experiments were similar and ranged from 0.02 to 0.03 d(-1) on average, indicating that if a proper sampling strategy is employed, bench-scale experiments can be used to represent full-scale composting conditions.

Modeling organic micro pollutant degradation kinetics during sewage sludge composting.

Degradation of 13 different organic micro-pollutants in sewage sludge during aerobic composting at 5 different temperatures over a 52 day period was investigated. Adequacy of two kinetic models: a single first order, and a dual first order expression (using an early (first 7 days) and a late-time (last 45 days) degradation coefficient), for describing micro-pollutant degradation, and kinetic constant dependency on composting temperature were evaluated. The results showed that both models provide relatively good descriptions of the degradation process, with the dual first order model being most accurate. The single first order degradation coefficient was 0.025 d(-1) on average across all compounds and temperatures. At early times, degradation was about three times faster than at later times. Average values of the early and late time degradation coefficients for the dual first order model were 0.066 d(-1) and 0.022 d(-1), respectively. On average 30% of the initial micro-pollutant mass present in the compost was degraded rapidly during the early stages of the composting process. Single first order and late time dual first order kinetic constants were strongly dependent on composting temperature with maximum values at temperatures of 35-65°C. In contrast the early time degradation coefficients were relatively independent of composting temperature.

Impact of compost process temperature on organic micro-pollutant degradation.

Aerobic composting has gained considerable attention because of its ability to remove organic micro-pollutants. Compost process temperature is a key parameter controlling degradation rate. Impact of process temperature on removal of 15 key organic micro-pollutants often found in sewage sludge (including two metabolites) during sewage sludge composting was investigated at 18-70°C over 52 days. Removal rates generally depended strongly on temperature and for all compounds an optimal temperature for removal was observed. Optimal temperatures for the 13 parent compounds ranged from 25 to 70°C and relative removal of the 13 parent compounds was as high as 99% across all combinations of compound and temperature with an average removal of 66%. The two metabolites were both formed and removed during the course of composting and the data indicated that metabolites may very well have other optimal removal temperatures than their parent compounds.

Quantifying measurement uncertainty in full-scale compost piles using organic micro-pollutant concentrations.

Reductions in measurement uncertainty for organic micro-pollutant concentrations in full scale compost piles using comprehensive sampling and allowing equilibration time before sampling were quantified. Results showed that both application of a comprehensive sampling procedure (involving sample crushing) and allowing one week of equilibration time before sampling reduces measurement uncertainty by about 50%. Results further showed that for measurements carried out on samples collected using a comprehensive procedure, measurement uncertainty was associated exclusively with the analytic methods applied. Application of statistical analyses confirmed that these results were significant at the 95% confidence level. Overall implications of these results are (1) that it is possible to eliminate uncertainty associated with material inhomogeneity and (2) that in order to reduce uncertainty, sampling procedure is very important early in the composting process but less so later in the process.

Optimized sampling strategy for measurement of biomass properties during full-scale composting.

Biomass to be composted is often very heterogeneous and collection of representative samples for determination of compost properties is therefore difficult, especially under full-scale conditions. During full-scale composting different biomasses in the amount of 10-100 tons are mixed, yielding a very heterogeneous mixture. Final sample size for compost property determination is usually a few grams compared with compost pile masses of hundreds of tons. Desired sample particle size is about 1 mm, while compost particle size ranges from 5 to 50 cm. This study focuses on the development of a strategy for sampling under full-scale conditions for minimum measurement uncertainty based on selected material properties. Optimization was conducted considering multiple parameters, such as number of pile turnings before sampling, number of samples collected, sample mass, sample homogenization, particle size reduction and number of replicate measurements. Measurement uncertainty was evaluated using water content, inorganic matter content and nutrient (nitrogen, phosphorus) content. For each parameter measurement variability was determined as a function of sampling strategy and used to identify optimal sampling strategy.