Toxicological evaluation of multi-class pesticide residues in vegetables and associated human health risk study for adults and children

This article describes, for the first time in 10 years, the toxicological evaluation of pesticide residues in highly consumed vegetables (35 commodities) and health risk studies. Among 1075 vegetable samples consisting mainly of tuber, root, fruiting, and Brassica, 20% of samples contained 38 pesticides in the range of 0.005–18.7 mg/kg and 1% > maximum residue limits (MRLs). Organophosphates and chloronitrile were most frequently found (20%) in the pesticide class. The highest concentration of 18.7 mg/kg was noted for dichlofluanid. Fruiting vegetables (8%), especially tomatoes (5%), were the most contaminated, while multi-residues were determined in 5% of the samples. Risk assessment was performed by analytical results and consumption on the 97.5 percentile expressed as hazard index (HI) and hazard quotient (HQ). The highest chronic HI was calculated for diazinon in lettuce (32% Acceptable Daily Intake (ADI) adults and 36% children) and for forbidden dieldrin in carrots (26%, 62% ADI). The highest acute HI was estimated for dichlofluanid in lettuce (69% Acute Reference Dose (ARfD)) for adults, whereas for children it was above the acceptance values of ARfD (168%). Organophosphate insecticides with common mode of action showed the greatest HQ (108% ADI). Vegetables may not be a serious problem for consumers, but investigations on pesticide residues are necessary to ensure food safety and the protection of human health, especially toward children who are more highly exposed to pesticides than adults.     

Residual Pattern and Dietary Intake of Iprodione on Grapes under Egyptian Field Conditions: A Prelude to Risk Assessment Profile

Field experiments were conducted in two different locations in the Nile delta to determine the residue levels and dissipation rates of iprodione in grapes. Iprodione was applied in different rates (recommended dose and two times recommended dose) and spraying times. Analysis was carried out using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The dissipation rates of iprodione were described using first-order kinetics and the half-life ranged from 8.8 to 9.4 days. There was a sharp decrease in the amount of iprodione residues 10 days after application. At harvest time, the remaining residues of iprodione were below the Food and Agriculture Organization (FAO)/World Health Organization (WHO) maximum residue level (MRL) of 10 mg/kg when measured 14 days after final application. The exposure to iprodione was assessed and compared to acceptable daily intake (ADI). Based on grape consumption, the estimated daily intakes of iprodione ranged from 0.2% to 1.1% of the ADI, showing insignificant risk to consumers.     

喷施农药对银耳生长的影响及膳食暴露风险评估

为制订银耳(Tremella fuciformis)栽培中农药合理使用的建议,以我国银耳主栽菌株Tr01为对象,研究8组常用农药对其生长的影响,采用食品安全指数法评估长期膳食银耳导致的农药残留慢性暴露健康风险.结果表明,除咪鲜胺乳油和哒螨灵、啶虫脒微乳剂的部分处理外,其余6组农药对银耳子实体生长并无显著影响.银耳中的农...     

Feeding strategies for the enhanced production of α-arbutin in the fed-batch fermentation of Xanthomonas maltophilia BT-112

To develop a cost-effective method for the enhanced production of α-arbutin using Xanthomonas maltophilia BT-112 as a biocatalyst, different fed-batch strategies such as constant feed rate fed-batch, constant hydroquinone (HQ) concentration fed-batch, exponential fed-batch and DO-control pulse fed-batch (DPFB) on α-arbutin production were investigated. The research results indicated that DPFB was an effective method for α-arbutin production. When fermentation with DO-control pulse feeding strategy to feed HQ and yeast extract was applied, the maximum concentrations of α-arbutin and cell dry weight were 61.7 and 4.21 g/L, respectively. The α-arbutin production was 394 % higher than that of the control (batch culture) and the molar conversion yield of α-arbutin reached 94.5 % based on the amount of HQ supplied (240 mM). Therefore, the results in this work provide an efficient and easily controlled method for industrial-scale production of α-arbutin.     

阿维菌素及其混剂对海南中蜂的急性毒性测定及风险评估

利用摄入法和点滴法测定阿维菌素、阿维 哒螨灵、阿维 灭幼脲以及哒螨灵对海南中蜂工蜂的急性经口和接触毒性。评估了这些农药对海南中蜂的风险性,评价了阿维菌素和哒螨灵混配剂的增效效果。毒力评价结果表明,急性经口试验中,阿维·灭幼脲（LC50为4.027 mg/L）对海南中蜂的毒性为高毒,其他三种药剂均为剧毒。急性接触试验中,四种农药对海南中蜂的急性接触毒性均为高毒。风险评估结果表明,哒螨灵对海南中蜂的危害商值为14.58,对海南中蜂危害不大,其他三种农药对海南中蜂都有害。增效评价结果表明,阿维·哒螨灵混配剂相对于单剂表现为增效作用。因此,应尽量避免在蜜源植物花期使用阿维菌素及其混配剂。     

Human health risk assessment of arsenic in groundwater aquifers of Lahore,Pakistan

The present study was conducted to estimate As concentration in groundwater and resulting human health risk in terms of chronic daily intake, hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR) both for oral and dermal exposure to As. Groundwater samples (n = 100) were collected from ten different towns of Lahore District (Pakistan). Arsenic concentration ranged from 2 to 111 µg L^?1 in groundwater samples of the study area, which was significantly greater than the safe limit of As (10 µg L^?1) in drinking water set by the World Health Organization. Health risk assessment of As showed that HQ (0.1–11) for oral exposure and HI (0.1–11) values also exceeded the typical toxic risk index value of 1. 9.75 × E-05–4.59 × E-03 and 5.89 × E-07–2.77 × E-05 for oral and dermal As exposure, respectively. Both CR and cancer index (CIs) values were higher than United States Environmental Protection Agency limit (10^?6), suggesting that people are at high risk of As-induced carcinogenicity from oral and dermal exposure to As in drinking water. It was concluded that As contamination of groundwater causes carcinogenic and noncarcinogenic health effects to the people; therefore, urgent management and remedial actions are required to protect people from As poisoning.     

Exposure Monitoring and Health Risk Assessment of 1-Bromopropane as a Cleaning Solvent in the Workplace

This study was conducted to estimate the health risk to workers exposed to 1-bromopropane (1-BP) used as a cleaning solvent in their workplaces. Fifty samples from 10 workplaces that use 1-BP as a cleaning solvent were obtained to assess 1-BP concentrations. An exposure assessment revealed central tendency exposure (CTE) and reasonable maximum exposure (RME) levels of 82.1 and 214.8 mg/m³, respectively. For risk characterization, the 1-BP exposure concentrations for reproductive and developmental toxicities were calculated as 2.8 and 8.5 mg/m³, respectively, and compared with the reference concentrations in the workplace. The CTE and RME hazard quotients (HQ) were, respectively, 29.4 and 77.0 for reproductive toxicity and 9.6 and 25.2 for developmental toxicity. The results of our 1-BP risk assessment indicated that the CTE-HQs for both categories were higher than the acceptable risk value of 1, indicating that 1-BP may be considered as harmful to workers.     

DDT and HCH (Organochlorine Pesticides) in Residential Soils and Health Assessment for Human Populations in Korba,India

Dichlorodiphenyltrichloroethane (DDT), hexachlorocyclohexane (HCH), and their isomers’ levels in residential soils were determined for the assessment of health risk in Korba, India. Observed concentrations of total HCH and total DDT in soils were more or less comparable with other parts of India and the world. ΣHCH and ΣDDT concentrations ranged between 0.9–20 μg kg^?1 and 2–315 μg kg^?1, respectively, which were lower than recommended soil quality guidelines indicating low ecotoxicological risk. Carcinogenic and non-carcinogenic impacts of HCH and DDT on human populations through soil ingestion were evaluated and presented. The incremental lifetime cancer risk (ILCR) for adults and children ranged between 7.8 × 10^?10–1.6 × 10^?7 and 4.1 × 10^?9–8.2 × 10^?7, respectively. Non-cancer health hazard quotient (HQ) ranged between 5.9 × 10^?7–1.8 × 10^?3 and 3.1 × 10^?6–9.4 × 10^?3, respectively, for adults and children. The estimated ILCR and HQ were within the safe acceptable limits of 10^?6–10^?4 and ≤1.0, respectively, indicating low risk to human populations from exposure to organochlorine pesticides (HCH and DDT) in the study area.     

Evaluation of groundwater contamination for fluoride and nitrate in semi-arid region of Nirmal Province,South India: A special emphasis on human health risk assessment (HHRA)

The main aim of this study was to assess the groundwater quality and human health risks of fluoride and nitrate contamination in Nirmal Province, South India, where groundwater is the primary source for drinking water. Hazard quotient (HQ) and total hazard index (THI) were calculated to estimate the non-carcinogenic risk to men, women, and children using the most substantial method recommended by United States Environmental Protection Agency (USEPA). The results of the study reveal that 26% and 20.59% of groundwater samples have significantly high nitrate and fluoride concentrations, exceeding the maximum permissible limits set by Bureau of Indian Standards (45 mg/L and 1.5 mg/L, respectively). Therefore, ingestion of high fluoride and nitrate water could be the chief reason for health risk in the study region. The total non-carcinogenic health risks for men, women, and children ranged from 2.95E?01 to 4.07E+00, 3.49E?01 to 4.80E+00, and 3.99E?01 to 5.50E+00, respectively. Moreover, 67.65%, 79.41%, and 82.35% of the total collected groundwater samples exceeded the permissible limit for acceptable total health index (THI = 1) for men, women, and children, respectively. Therefore, the health risk assessment suggests that children face higher health risk than men and women in the study region.     

Effects of the replacement of concentrate and fibre-rich hay by high-quality hay on chewing,rumination and nutrient digestibility in non-lactating Holstein cows

The aim of this study was to investigate the effects of high-quality hay with an elevated sugar content alone or with graded amounts of concentrate feed on chewing and ruminating activity, apparent total tract digestibility (ATTD) and ruminal pH at different time points after feeding in the free ruminal liquid (FRL) and the particle-associated ruminal liquid (PARL). Eight rumen cannulated non-lactating Holstein cows were arranged in a Latin square design in four experimental runs lasting 25 d each. The four diets tested were 60NQ (60% normal-quality hay + 40% concentrate), 60HQ (60% high-quality hay + 40% concentrate), 75HQ (75% high-quality hay + 25% concentrate) and 100HQ (100% high-quality hay). Normal and high-quality hays differed in sugar contents (11.3% vs. 18.7% in dry matter [DM]), neutral detergent fibre (NDF; 57.7% vs. 46.3% in DM), acid detergent fibre (ADF, 35.0% vs. 23.5% in DM) and crude protein (CP, 11.3% vs. 23.5% in DM). Data showed that ATTD of DM, CP, NDF and ADF was higher with the high-quality hay diets. Time spent eating was reduced with high-quality hay. However, time spent ruminating was longest in Group 100HQ. In all groups, ruminal pH of FRL and PARL decreased with time after the morning feeding. But 10 h later, pH of Group 100HQ was higher again compared with the other groups. Considering the average pH in FRL over all measured time points, cows in Groups 60NQ and 100HQ had higher pH values of 6.85 and 6.83, respectively. Regarding pH values in PARL, animals of Group 60NQ displayed the highest pH value (6.68), whereas the lowest value of 6.21 was found in Group 60HQ. Overall, results suggest that high-quality hay maintains the diet’s structural effectiveness by stimulating rumination and stabilising ruminal pH while greatly improving ATTD. However, the structural effectiveness of the high-quality hay gets impaired with increasing proportion of concentrate feed in the diet.     

Occurrence and risk assessment of organophosphorus pesticide residues in Chinese tea

Tea is the second widely consumed beverage next to water. Tea drinking is one of the important pathways for human exposure of organonphosphorus pesticide. Consequently, incidence of organonphosphorus pesticide residues and risk assessment should be clear. In this study, the level of organonphosphorus pesticide residues in 810 Chinese teas manufactured between 2010–2013 was investigated using gas chromatography coupled with tandem mass spectrometry and a flame photometric detector. Incidence of organonphosphorus pesticide residues occurred with a frequency of 29% and the average concentration of 93 μg kg^?1. The residue levels varied from tea types, sale spots, and production area. Chlorpyrifos, isocarbophos, and triazophos were the only three organonphosphorus pesticides with detectable residues, and the detectable rates were 13.0%, 13.6%, and 17.4%, respectively. The corresponding average daily intake of chlorpyrifos, isocarbophos, and triazophos by tea drinking was 0.000083 μg kg^?1 bw day^?1, 0.0036 μg kg^?1 bw day^?1, and 0.0022 μg kg^?1 bw day^?1. These results showed that the total hazard quotient of organonphosphorus pesticide pesticides from tea drinking was less than 0.02 and that the tea-drinking originated organonphosphorus pesticide exposure had a little adverse health effect for human being.     

Assessment of Fluoride in Three Selected Polluted Environments along the Egyptian Mediterranean Sea: Effects on Local Populations

Fluoride ion (F^?) is a relevant component of concern due to its potential toxicity for humankind. This study clarifies the status of F^? for human health in three polluted regions along the Egyptian Mediterranean Sea coast, and determining its contents in seawater and different fish tissues (muscle, skin, brain, and bone). Fluoride ion concentrations in different fish tissues had a descending trend of brain > skin > muscle > bone with averages of 26.8 ± 26.0, 24.8 ± 6.5, 12.7 ± 2.3, and 9.0 ± 1.6 μg F^?/g wet wt, respectively. The bioconcentration factor for fluoride ion in different fish tissues was determined and multivariate analyses were conducted. The human health hazard assessment from fish consumption and seawater contact using hazard quotient (HQ) and ingestion and dermal absorption dose of whole body for different ages of females and males as well as the specified body parts (legs, arms, and hands) were calculated. Although the calculated daily intake values for ingestion of fish in the present study were lower than some established tolerable daily intake values, their hazard quotients were within 1 ≥ HQ < 10 and may reflect a possible fluoride adverse effect on human health from the consumption of the gathered fish species.     

Molecular in silico structure and recombination analysis of betasatellite in Calotropis procera associated with begomovirus

The uncharacterised betasatellite of begomovirus associated with Calotropis procera was characterised by using molecular and in silico tools and techniques. Attempts to identify the presence of a DNA-β in the infected C. procera samples, using rolling circular amplification (RCA) followed by restriction digestion, produced a ca. 1.4 kb product, corresponding to that expected for a full-length amplicon from a betasatellite, which was sequenced (accession number HQ631430). During BLASTp, analysis of second reading frame of HQ631430 (HQ631430/2-f) against Protein Databank revealed 35% identity with Tryptophanyl–tRNA synthetase of Giardia lamblia (3FOC). Ramachandran plot of HQ631430/2-f.pdb had only 57.1% residues in the most favoured region while 3FOC.pdb had 94.2% residues in the most favoured region; therefore, only template 3FOC.pdb model could be placed in good quality category. The protein binding function was predicted for HQ631430/2-f as an important functional site of the model with 0.29 confidence level through 3d2GO. The Croton yellow vein mosaic betasatellite (GU111995 CroYVMB) serve as major parent and Croton yellow vein mosaic betasatellite-Panipat 8 (HM143908 PaLCuVM) as minor parent for HQ631430. Perhaps this is the first report of recombination in Croton yellow vein mosaic betasatellite (HQ631430).     

Risk Ranking of Antimicrobials in the Aquatic Environment from Human Consumption: An Irish Case Study

A mechanistic model is presented for determination of antimicrobial presence in the environment, using antimicrobial characteristics and Irish-specific usage data. The model simulates release of antimicrobials into the aquatic environment by integrating the effects of antimicrobial use, metabolism, degradation, and dilution. Predicted environmental concentrations (PECs) were ranked in relation to their potential to select for resistant bacteria, toxicity (chronic and acute), and hazard quotient (HQ). The simulated mean PECs of penicillins (PEN), β-lactams (BET), tetracyclines (TET), macrolides (MAC), quinolone/fluoroquinolones (Q/F), and sulphonamides/trimethoprim (S/T) were 1.05, 0.19, 0.06, 0.07, 0.02, and 0.08 mg/m³, respectively. All antimicrobials, excluding Q/F, showed a low HQ (<1) indicating low toxicity. Q/F had a HQ of 1.51 indicating moderate toxicity. All antimicrobial groups expressed varying resistance formation potential with Q/F having the highest. Q/F also exhibited the lowest degradation rate. A sensitivity analysis indicated a possible role for considering metabolism during regulation of new antimicrobials as this can significantly influence PEC values. The observed results suggest that current antimicrobial use can lead to levels in the environment that may increase resistance formation. The results and limitations presented here accentuate the need for further investigation into antimicrobials in the environment and contribution to resistant strains.     

Health risk assessment of fluoride in water distribution network of Mashhad,Iran

High and low levels of fluoride in drinking waters have been considered as a major public health issue in recent years. This cross-sectional study was conducted over five consecutive years (from 2012 to 2016) in the water distribution network of Mashhad city, Iran with the objectives of determining levels of fluoride and to perform health risk assessment among residents in the study area. Water samples were taken from 30 stations and were analyzed using UV-visible spectrophotometer. The mean annual concentrations of fluoride in all stations during five years of consecutive study were lower than the respective maximum permissible limits (1.5 mg/L) in water as regulated by the WHO. The human health risk assessment was performed by calculating the chronic daily intake and hazard quotient (HQ) of fluoride through human oral intake for adults (men and women) and children for each year during a five-year study. Health risk analysis in this study presented that the non-carcinogenic risk associated with fluoride exposure through drinking water in Mashhad was mostly acceptable because the mean HQ values of fluoride were lower than 1.     

Metal contamination and human health risk associated with the consumption of Labeo rosae from the Olifants River system,South Africa

The Olifants River, a tributary of the Limpopo River system, is one of the most polluted rivers in South Africa. In May 2011 the concentrations of metals in fish muscle tissue from two impoundments, Loskop and Flag Boshielo dams, on the Olifants River were measured and a human health risk assessment conducted to investigate whether it was safe to consume Labeo rosae from these impoundments. Labeo rosae is one of the most common pan fish in these impoundments and is readily available to rural communities. Metals are accumulating in the muscle tissue of L. rosae even although the fish populations appear to be healthy. At Loskop Dam all L. rosae analysed exceeded the recommended hazard quotient (HQ) of 1 for antimony, and less than 50% exceeded that for lead. At Flag Boshielo Dam, the recommended HQ was exceeded for lead in less than 50% of L. rosae analysed, and more than 50% exceeded that for antimony. The weekly consumption of 150?g of L. rosae muscle tissue from these impoundments may pose an unacceptable health risk to rural communities.     

Health risk assessment due to exposure of arsenic contamination in drinking water of district Shiekhupura,Punjab, Pakistan

Abstract

The present study was conducted to assess the magnitude and health impacts of As in drinking water. Drinking water samples (n?=?60) were collected from twenty different sites of Shiekhupura District (Pakistan). Health risk assessment through average daily dose (ADD), hazard indices (HI), hazard quotient (HQ), carcinogenic risk (CR), and cancer indices (CI) for dermal and oral exposure were determined. Results revealed that As concentration ranged from 2 to 900?µg?L^?1 in water samples, which was significantly greater than the safe limit of As (10?µg?L^?1) in water. Health risk assessment of As showed that ADD (1.07E?02–9.85E?04), HQ (1.06E+01–9.85E+00), and CR (1.60E?02–9.85E?04) for oral exposure and ADD (1.03E?05–9.69E?06), HQ (1.19E?02–7.96E?03), and CR (1.11E?05–8.98E?05) for dermal exposure which were exceeded the toxic risk index value. Comparison of the two exposure pathways indicated that the oral exposure is much higher risk than the dermal contact. Both values of HI and CI were greater than WHO limit. It is concluded that residents of study area are at higher risk of As induced diseases and carcinogenicity.     

Health risk assessment of ‘tiger prawn seed’ collectors exposed to heavy metal pollution in the conserved mangrove forest of Indian Sundarbans: A socio-environmental perspective

Heavy metals contamination from anthropogenic sources in waterways of conserved mangrove ecosystem (Indian Sundarbans) poses serious health hazard to the economically marginalized ‘tiger prawn seed’ (TPS) collectors. Principal component analysis identifies Pb, Ni and Cd as anthropogenic pollutant in Indian Sundarbans. It is observed that Cu, Fe and Zn concentration increases in monsoon, whereas concentration of Cd and Pb decreases in comparison to pre-monsoon levels at all seven fishing villages. Economic status has been assessed using Wealth Rank Tool, which indicates 16–71% of population is in acute economic stress conditions and 5–70% of populations engaged in unsustainable TPS collection for their livelihood. Focus group discussion shows that collectors are exposed (exposure time (ET)) to contaminated water for 3–7 h/d, and lifetime exposure (exposure duration (ED)) varies from 5 to 20 yr. Using site-specific ET and ED results, cumulative hazard quotient (HQ) dermal is estimated to be higher in female than in male. HQ varies from medium (≥1 to <4) to high (>4) due to Cd pollution (0.1–0.26 mg L^-1). The study suggests that promoting alternative sustainable livelihood through group-based organizations (poultry, organic farming, entrepreneurship and transport) could be an effective solution to this problem.     

Residue dynamics and risk assessment of dimethoate in sweet potato,purple flowering stalk,Chinese kale,celery, and soil

Residue dynamics and risk assessment of the insecticide dimethoate applied to sweet potato, purple flowering stalk, Chinese kale, celery were investigated under the climatic conditions of China. The dissipation experiments indicated that the half-lives of dimethoate in purple flowering stalk, Chinese kale, celery, and soil were 5.9–6.5, 3.8–5.1, 3.5–5.4, 3.4–3.6 d, respectively. The terminal residues of dimethoate and omethoate in the vegetables and soil ranged from 0.008 to 1.73 mg kg^?1 at preharvest intervals of 3, 5, and 7 d. The results showed risk quotient (RQ) of <1 for sweet potato, Chinese kale, and celery, and of >1 for purple flowering stalk when under the age of 18, indicating that spraying dimethoate on sweet potato, Chinese kale, and celery at the recommended dosage is safe for human consumption, whereas spraying it on purple flowering stalk is associated with some risks to human health.