The concentration and health risk assessment of nitrate in vegetables and fruits samples of Iran

Nitrate levels in vegetables from markets in Tehran, Iran

This study is aimed at measuring nitrate levels in different vegetables from Tehran's markets that are consumed raw and fresh and to evaluate human health risk. Basil, parsley, radish leaves, cress, leek, radish, spring onion were randomly collected from local markets and the nitrate content was analysed by spectrophotometry. Average nitrate levels in the samples were 40.1, 45.2, 50.0, 51.8, 55.4, 90.2 and 110 mg kg-1 in parsley, leek, basil, radish leaves, cress, radish and spring onion, respectively. The average content in all samples was below Iranian standard limits. Tuber vegetables had significantly higher nitrate content than (green) leafy vegetables.

Distribution of nitrate/nitrite and toxic metals in the soil-potato system and its health risk assessment in Iran

Potato is one of the essential food products whose health quality is greatly influenced by soil contamination and properties. In the current study, we have investigated the physicochemical characteristics of agricultural areas and the accumulation of nitrite/nitrate and metals in potato products in Hamedan, Iran. After determining the physicochemical characteristics of soil samples from four agricultural regions of Hamedan, 48 potato samples were collected from these regions. The heavy metals and nitrate/nitrite content were determined by ICP-OES and calorimetric methods, respectively. A negative correlation was observed between soil pH changes with nitrite/nitrate content and the accumulation of some heavy elements in potatoes. Furthermore, a positive correlation was found between soil phosphorus content and lead accumulation in potato. In present study, the amounts of lead, nitrate, and nitrite in 83.3%, 56%, and 12% of the collected samples were higher than the permissible limit reported by the World Health Organization (WHO), respectively. The EDI range for nitrate and nitrite was determined to be 130-260 and 1.4-2.7 µg/kg/day, respectively, which is much lower than the RfD set by the US Environmental Protection Agency (USEPA) for nitrite and nitrate. Among metal pollutants, the toxic risk caused by lead in potato consumers was higher than the threshold limit. In conclusion, our findings showed that the physicochemical characteristics of the soil could effectively increase the availability of metal pollutants and nitrite/nitrate to the potato product and significantly reduce its health quality. Therefore, monitoring these pollutants in the soil-potato system, preventing the entry of industrial wastewater, and managing the use of agricultural fertilizers can effectively improve the health of this product for consumers.

Nitrates in industrial and traditional tomato paste from Arsenjan City, Iran: a health risk assessment study

A comprehensive approach was used for the first time to measure NO3- risk in tomato paste consumption; besides a robust deterministic and probabilistic method was used. The mean levels of NO3- in homemade and industrial tomato paste were 7.36 mg/kg and 43.69 mg/kg, respectively. The Monte Carlo simulation confirmed that these values were below normal levels (HQ less than 1). The sensitivity analysis displayed that FIR was the main factor affecting the risk to human health in both groups. The interactive plot demonstrated the interaction between C and IR for children and adults in both types of tomato paste. This study concludes that NO3- ingestion due to tomato paste consumption poses no significant health risk. However, considering that food and water constitute the primary sources of NO3- intake, continuous monitoring is recommended due to potential health risks associated with excessive NO3- consumption, including certain forms of cancer.

Content of potentially toxic elements (PTEs) in various animal meats: a meta-analysis study, systematic review, and health risk assessment

Meat comprises the main part of the diet in many countries around the world. The present study aimed to assess potentially toxic elements (PTEs) lead (Pb), arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), zinc (Zn), and iron (Fe) in various meats (camel, chicken, cow, pork, birds, seafood (fish and crab), and sheep). The present study was performed on the concentration of PTEs in various meats by different databases including Scopus, PubMed, and Web of Science along with a meta-analysis. Additionally, the non-carcinogenic risk was assessed by calculating the total hazard quotient (TTHQ). According to findings, the highest concentration of Cd was related to sea (0.460 mg/kg). The highest concentrations of Cd and As were reported in camel meat (1.965 and 1.503 mg/kg, respectively). Regarding trace elements, the highest concentrations of Zn, Fe, Cu, and Ni were observed in seafood (fish and crab), cow meat, and bird's meat (71.159 mg/kg, 36.608 mg/kg, 8.680 mg/kg, and 1.592 mg/kg, respectively). Moreover, considering the type of continents based on the concentration of PTEs in various meats, the highest concentrations of As (0.792 mg/kg), Cd (0.315 mg/kg), Pb (1.049 mg/kg), Fe (44.088 mg/kg), and Ni (1.113 mg/kg) were related to Eastern Mediterranean region (EMRO), African Region (AFRO), EMRO, the Pan American Health Organization (PAHO), and EMRO, respectively. However, the highest concentrations of Cu (4.846 mg/kg) and Zn (60.742 mg/kg) were related to European Region (EURO) and AFRO, respectively. On the other hand, the result of the risk assessment indicated that the risk pattern was different among countries.

Nitrate in groundwater and agricultural products: intake and risk assessment in northeastern Iran

The suitability of groundwater and agricultural products for human consumption requires determining levels and assessing the health risks associated with potential pollutants. Here, particularly pollution with nitrate still remains a challenge, especially for those urban areas suffering from insufficient sewage collection systems, resulting in contaminating soil, endangering food safety, and deteriorating drinking water quality. In the present study, nitrate concentrations in the commonly consumed fruit and vegetable species were determined, and the results, together with the groundwater nitrate levels, were used to assess the associated health risks for Mashhad city residents. For this assessment, 261 water samples and 16 produce types were used to compute the daily intake of nitrate. Nitrate in groundwater was analyzed using a spectrophotometer, and produce species were examined using High-Performance Liquid Chromatography. Ward's hierarchical cluster analysis was applied for categorizing produce samples with regard to their nitrate content. Additionally, to account for the sanitation hazards associated with groundwater quality for drinking purposes, total coliform and turbidity were also assessed using the membrane filter (MF) technique and a nephelometer, respectively. Nitrate concentrations exceeded the prescribed permissible limits in 42% of the groundwater wells. The outcomes also exhibit significantly higher nitrate accumulation levels in root-tuber vegetables and leafy vegetables compared to fruit vegetables and fruits. Using cluster analysis, the accumulation of nitrate in vegetables and fruits was categorized into four clusters, specifying that radish contributes to 65.8% of the total content of nitrate in all samples. The Estimated Daily Intake (EDI) of nitrate and Health Risk Index (HRI) associated with consumption of groundwater exceeded the prescribed limit for the children's target group in Mashhad's south and central parts. Likewise, EDI and HRI values for produce consumption, in most samples, were found to be in the tolerable range, except for radish, lettuce, and cabbage, potentially posing risks for both children and adult consumers. The total coliforms in groundwater were found to violate the prescribed limit at 78.93% of the sampling locations and were generally much higher over the city's central and southern areas. A relatively strong correlation (R2 = 0.6307) between total coliform and nitrate concentrations suggests the release of anthropogenic pollution (i.e., sewage and manure) in the central and southern Mashhad.

Plant biomass as potential economic commodities for agricultural purposes

The world’s population is growing continually and is projected to reach nine billion by the year 2050. This growth rate requires increased and economically viable food production and an adequate supply of quality water to sustain life. Increased food production and supply of water require adding fertilizers and possible recycling of wastewater, to address the improvement of soils’ nutritional status and potable water shortages, respectively. The objectives of this work were to determine the nutrients in sewage-impacted wastewater, borehole water, agricultural waste, and commercial fertilizer (control) materials, and their heavy metal content was also carried out to determine their suitability for use. In addition, Moringa seed pods and Morula nutshells were investigated as a bioremedial approach for the removal of toxic metals from aqueous samples. An attempt to regenerate sorbent was made since the saturated sorbents that contain the metal ions are not safe for disposal as they can pollute the environment. Nutrients were analyzed by HPLC, while metals were analyzed using a Varian 220FS Atomic Absorption Spectrometer operated with air/acetylene. Nonedible agricultural materials were found to contain appreciable amounts of plant nutrients such as nitrates (NO₃^-), nitrites (NO₂^-), and phosphates (PO₄^3-) as well as metal ions such as magnesium, copper, and zinc, which are beneficial for plant growth. Results obtained from analysis of sewage water effluent showed that heavy metal and nutrient concentrations decreased in the treatment stage. The utilization of Moringa oleifera seed pods for metal removal from wastewater is viable and would reduce costs for waste disposal and can offer alternatives to conventional methods for the removal of unwanted or toxic species from the environment. It showed potential for removing selected metal ions such as Pb, Cd, Cu, Fe, and Zn from polluted water. This organically treated wastewater is environmentally friendly and may be used for applications which do not require potable water, such as irrigating golf courses, lawns, and crops, or for industrial purposes, if proper measures are taken to ensure its quality.

Assessment of Mineral Nutrient Efficiency in Genetically Diverse Spinach Accessions by Biochemical and Functional Marker Strategies

Leafy vegetable crops are considered as a natural source of mineral nutrients that could decrease the risk factor of many growth issues in children and adults. Spinach is globally considered as the most desirable leafy crop, due to its taste and nutrient richness along with greater nitrate contents and better nitrogen use efficiency. To evaluate the mineral nutrient efficiency of this crop, thirty genetically diverse spinach accessions were analyzed through nutritional and functional marker strategies. The accession 163,310 from Pakistan was found to be rich in minerals (sodium, calcium, potassium, zinc, and manganese) and nitrates. However, the oxalate contents were lesser in the accessions that had greater quantity of nutrients. These represented a negative correlation between mineral availability and oxalate accumulation in the leaves. To study the relationship of oxalates and minerals in the accessions, a functional marker analysis was performed, based on the genes involved in oxalate metabolism and disease resistance in spinach. High level of genetic polymorphism was observed among the accessions represented with 115 polymorphic bands out of 130 bands. Heat map clustering represented the accessions from Asian countries (Pakistan, India, China, and Iran) as the most adaptable accessions to the local environment. The correlation between nutritional and genetic analysis also revealed the nutrient richness of these accessions along with good oxalate metabolism and disease resistance. Hence, these accessions could be considered as useful genotypes in future breeding programs.

Concentration of Potentially Toxic Elements in Vegetable Oils and Health Risk Assessment: a Systematic Review and Meta-analysis

The present study evaluates the concentration of potentially toxic elements (PTEs), including Pb, Cd, As, Fe, Zn, Cu, and Ni, in vegetable oils through a meta-analytic approach. The published studies in relation to the concentrations of PTEs in vegetable oils were retrieved from major international databases such as PubMed, Scopus, Web of Science, and Embase followed by meta-analysis. Moreover, the health risk assessment was evaluated using total target hazard quotient (TTHQ) by a Monte Carlo simulation (MCS) model. According to the results of 51 articles included among 958 retrieved studies, the concentrations of the PTEs were as follows: Cd ≈As (0.110 mg/kg) > Pb (0.086 mg/kg) in cottonseed, canola, and olive oil and Fe (12.964 mg/kg) > Zn (1.044 mg/kg) > Ni (0.893 mg/kg) > Cu (0.264 mg/kg) in cottonseed, olive, and soybean for trace elementals, respectively. Based on the continent type, the higher concentration of Cd, As, and Pb was related to PAHO (American region) and AFRO (African region), and the higher concentrations of Fe, Zn, Cu, and Ni were observed in WPRO (Western Pacific Region), EMRO (Eastern Mediterranean Region), and AFRO. On the other hand, non-carcinogenic health risk assessment of the PTEs indicated that there was a different risk pattern in various countries, and the TTHQ level in adult groups was lower than 1. It can be concluded that the consumption of vegetable oils is safe and does not pose risk to the health of consumers.

Simultaneous multi-determination of pesticide residues in black tea leaves and infusion: a risk assessment study

This study aimed to investigate the concentration of 33 pesticide residues in 60 black tea samples collected from Iran, determine their transfer rate, and assess their health risk during brewing. Pesticide extraction and analysis were performed by using a quick, easy, cheap, effective, rugged, and safe (QuEChERS) method and gas chromatography/tandem mass spectrometry (GC-MS/MS), respectively. The limits of detection (LOD) and the limits of quantification (LOQ) of pesticides were ranged 0.1-7.26 and 0.8-24 μg/kg for dried tea leaves and 0.03-3.1 and 0.09-10 μg/L for the tea infusion, respectively. The levels of pesticide residue in 52 (86.67%) out of 60 tea samples were above the LOD (0.1-7.26 μg/kg). Twenty four (40%) of the samples contained pesticides in a concentration higher than the maximum residue limit (MRL) set by the European Commission (EC). Seven out of 33 validated pesticides were detected in dried tea leaf samples that only four of seven, including buprofezin, chlorpyrifos, hexaconazole, and triflumizole, were transferred into tea infusion, demonstrating that the concentrations of pesticides in infusion were raised during brewing. The risk assessment study for detected pesticides in the tea infusion samples indicated that this beverage consumption was safe for consumers, while the mean residue of some pesticides in positive samples was higher than the MRL; therefore, periodic control of these pesticides should be regularly implemented.

Study of nitrate levels in fruits and vegetables to assess the potential health risks in Bangladesh

Nitrate is a chemical compound naturally present in fruits and vegetables. This study aims at assessing the nitrate levels and health risks arising from high consumption of fruits and vegetables in Bangladesh. Sixteen species of fruits and vegetables were examined for nitrates using High-Performance Liquid Chromatography with Photo Diode Array (PDA) detector. Ward's hierarchical cluster analysis was carried out to identify the cluster of tested fruits and vegetables for the nitrate contents. A point estimate of the daily intake was applied to find the health risks that arise due to elevated levels of nitrate in fruits and vegetables. The results show that root and tuber vegetables accumulate significantly higher levels of nitrate in comparison to fruits and fruit vegetables (P < 0.05). In cluster analysis, the nitrate accumulation of fruits and vegetables show four clear clusters contributing to 29.54%, 7.17%, 4.42%, and 58.57% of the total nitrate content in the entire sample. The risk assessment of the Estimated Daily Intake (EDI) and Health Risk Index (HRI) of almost all the tested samples was in the acceptable range, except for radish, thereby indicating the acceptance of risk due to nitrate intake in Bangladesh. As nitrate may have had risk factor for health, during cultivation and storing the product should be properly monitored.

Nitrate Levels in Rural Drinking Water in Belize

BACKGROUND

Health issues have been associated with the consumption of high levels of nitrates in drinking water. Rural agricultural communities in Belize play a large role in the economic growth of the country. These communities obtain drinking water directly from the ground and may be susceptible to nitrate consumption and at risk of developing diseases associated with nitrates.

OBJECTIVES

The present study examined nitrate levels in Belize's rural water supply with the aim of assessing its suitability for human and livestock consumption. The study also provides baseline data for monitoring the concentration of nitrates to prevent public health hazards in Belize.

METHODS

Forty-three (43) water samples from reservoirs, wells, vats, and standpipes were collected from 40 villages in Belize and analyzed for nitrates using the cadmium reduction method. Nitrates were detected with an Orion® AquaMate® 8000 UV-Vis spectrophotometer at 520 nm. The Belize Coastal Zone Management Authority and Institute laboratory analyzed all water samples for nitrates.

RESULTS

Except for four water samples from four different sites, all analyzed water samples were found to contain nitrate levels below 10 mg/L. Nitrate levels above 10 mg/L were seen in a few samples in the northern part of the country, probably due to agricultural activities in these areas.

CONCLUSIONS

Belize's rural drinking water contains low levels of nitrates, except for a few villages where the levels exceeded the acceptable limit of 10 mg/L. Higher levels of nitrates detected in a few villages need regular evaluation and monitoring to avoid public health issues as well as prevent harm to livestock.

COMPETING INTERESTS

The authors declare no competing financial interests.