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Arsenic (As), a carcinogenic metalloid, is a serious threat to humans due to increased exposure through contaminated water and food. Rice is a staple food and feeds over half of the World's population. Among cereals, rice is more efficient in As uptake and its acquisition into rice grains adversely affect the quality of rice as well as the consumer’s health. The exploitation of genetic variation between rice genotypes for their ability to tolerate water limitations and As accumulation in grains is crucial. The study aimed to investigate the genetic potential of seven rice genotypes for their ability to withstand water limitation (aerobic cultivation) and As toxicity (As-100 µM). The results revealed that under aerobic cultivation system rice genotypes showed less As accumulation in the grains as compared to anaerobic cultivation. Moreover, among all the rice genotypes, less As accumulation in grains was observed in DHAN 140A (2.36 and 3.65 µg g−1) and Shaheen Basmati (2.92 and 3.55 µg g−1), respectively, under aerobic and anaerobic cultivation at high As soil contamination (As-100). Rice genotypes differentially responded against As stress and the cultivation conditions in terms of growth attributes and elemental composition of the plants. Moreover, health risk indices (i.e. ILTCR and HQ) indicate high carcinogenic and non-carcinogenic risks associated with rice consumption grown under high As stress. However, the risks were several folds higher in anaerobically than aerobically cultivated rice genotypes. Among all the genotypes, DHAN 140A indicated less risk, irrespective to the cultivation condition due to decreased As uptake and accumulation of in the grains. The study demonstrated that aerobic water management and selection of genotypes with low As accumulation could be appropriate options to minimize the health risk to human beings.

To meet the food demand of the increasing world population, use of insecticides is increasing day by day. However, intensive application of insecticides has increased the health risks to the human. Therefore, sustainable alternatives with a limited or no harm to the human and environment are always preferable. A study was conducted to determine the effect of rice husk biochar (RHB) on brinjal growth, mineral nutrients and insect infestations. The soil filled pots (7 kg pot−1) were amended with various levels of rice husk biochar (Control, RHB 3.5, RHB 7, RHB 14, RHB 21 and RHB 28 g pot−1) and its effects were determined on brinjal plant. Rice biochar (RHB 28 g pot−1) amended plant produced maximum biomass. Further, results also showed that higher doses of RHB significantly lower the insect infestation. Biochar treatment has also improved the plant mineral nutrients especially silicon (Si) concentration in the leaves. Hence, it is concluded that RHB tends to reduce insect infestation on brinjal plants by improving Si uptake and it may provide a strategy to sustain brinjal production. However, further studies must be carried out for comparative efficacy of the RHB with insecticide in deterring insect infestation for its widespread recommendations.

Most of the developing countries including Pakistan have poor sanitary conditions which cause numerous diseases in human. Therefore, the present work aimed at evaluating the physicochemical and microbial contamination of drinking water in urban areas of three tehsils (Vehari, Mailsi and Burewala) of district Vehari based on occurrence of water-borne diseases. Forty-one water samples (six from tehsil municipal administration (TMA) water supply and 35 from electric pump) were collected from various locations of district Vehari for physicochemical and microbial analysis. In all the sampling sites pH (7.2–7.7), Phosphate (PO4−3) (0.00–0.94 mg/L), Sulphate (SO4−2) (0.00–172.8 mg/L), Magnesium (Mg+2) (4.55–40.7 mg/L), Iron (Fe+2) (0.00–0.09 mg/L), Copper (Cu+2) (0.00–0.04 mg/L), Zinc (Zn+2) (0.00–0.15 mg/L) and Manganese (Mn+2) (0.00–0.01 mg/L) were found under WHO limits. Microbial contamination of Eschrichia coli and coliform were found in water samples of F-Block, D-Block and C-Block of tehsil Vehari. Results revealed that the values of certain parameters such as electrical conductivity (0.34–2.23 mS/cm), total dissolved solids (123–1430.4 mg/L), Sodium (Na+) (55.5–327.5 mg/L), Calcium (Ca+2) (7.1–115 mg/L), Potassium (K+) (3.9–17.75 mg/L), Chloride (Cl−) (0.00–479.25 mg/L), and Nitrate (NO3−) (0.59–12.14 mg/L) exceed WHO limits in Sharqi Colony, Lalazar, Health Colony, TMA Sharqi Colony, Y-Block, 9-11 WB, College Town and 13-WB areas of district Vehari. Moreover, the survey of the sampled area was also conducted to assess public perception regarding water quality, its treatment, sanitation practices and possible reasons for the occurrence of water borne diseases. The survey results showed that 48.6% of the respondents disagreed that drinking water of their area is good. Cross tab analysis exhibited that respondents from different gender (65.3%), marital status (65.3%) and family type (65.3%) did not treat drinking water before use. Peoples who were not satisfied with their drinking water quality reported more disease development (45.8%) compared to those who were satisfied (11.1%) with their drinking water quality.

Silicon (Si) is the second most abundant element in the lithosphere. Soils commonly contain as much as 30% Si, the majority of which is found in minerals and rocks. In plants, the element Si is recognized as a “beneficial quasi-essential” mineral nutrient. It is taken up by the plant roots and trans-located to aerial parts through transpiration streams. Naturally, its accumulation in aerial parts augments its polymerization in the intercellular spaces and beneath the cuticles creates a barrier against pathogen attack. Moreover, soluble Si in the cytosol triggers various metabolic pathways that result in the production of jasmonic acid and herbivore induced plant organic compounds. Combination of these Si-mediated physical and biochemical processes enhances plant defenses against biotic stresses (insects, fungus and bacteria). In addition, soluble Si in the plant system attracts natural predators and parasitoids during pest attack and consequently increases biological control. Although, a large set of data shows that Si provides natural defense against pest attack, application of Si as a pest control agent has not gained much attention from the scientists, policy makers and farming communities. Here, current knowledge regarding Si-mediated plant defense to pest attack is reviewed. Si-application tends to reduce pest infestations and may provide a sustainable environment friendly integrated strategy as an alternative to extensive pesticide use.

Lithium (Li) exploitation for industrial and domestic use is resulting in a buildup of the element in various environmental components that results in potential toxicity to living systems. Therefore, a soil culture experiment was conducted to evaluate the effects of increasing concentration of Li (0, 20, 40, 60, and 80 mg kg-1 soil) on spinach growth, the effects of Li uptake, and its effects on various physiological attributes of the crop. The results showed that lower levels of Li in soil (20 mg Li kg-1) improve the growth of spinach plants, while a higher concentration of applied Li enhanced the pigment contents. Higher concentrations of Li in soil interfered with potassium and calcium uptake in plants. Moreover, increasing Li concentration resulted in higher activities of antioxidant enzymes activity in spinach shoots. From these results, it is concluded that spinach shoot accumulated higher concentrations of Li without showing any visual toxicity symptoms. Therefore, the study concludes that Li ion was mostly deposited in leaves rather than in roots which may cause potential human health risk on the consumption of Li-contaminated plants. Therefore, the cultivation of leafy vegetables in Li-affected soils should be avoided to reduce the potential human health risks.

Arsenic (As) is a toxic metalloid. Serious concerns have been raised in literature owing to its potential toxicity towards living beings. The metalloid causes various water- and food-borne diseases. Among food crops, rice contains the highest concentrations of As. Consuming As-contaminated rice results in serious health issues. Arsenic concentration in rice is governed by various factors in the rhizosphere such as availability and concentration of various mineral nutrients (iron, phosphate, sulfur and silicon) in soil solution, soil oxidation/reduction status, inter-conversion between organic and inorganic As compounds. Agronomic and civil engineering methods can be adopted to decrease As accumulation in rice. Agronomic methods such as improving soil porosity/aeration by irrigation management or creating the conditions favorable for As-precipitate formation, and decreasing As uptake and translocation by adding a inorganic nutrients that compete with As are easy and cost effective techniques at field scale. This review focuses on the factors regulating and competing As in soil-plant system and As accumulation in rice grains. Therefore, it is suggested that judicious use of water, management of soil, antagonistic effects of various inorganic plant-nutrients to As should be considered in rice cultivated areas to mitigate the building up of As in human food chain and with minimum negative impact to the environment.

Chromium (Cr) is becoming a potential pollutant with the passage of time. Higher intake of Cr does not only affect the productivity of crops, but also the quality of food produced in Cr polluted soils. In the past, foliar application of Fe is widely studied regarding their potential to alleviate Cr toxicity. However, limited information is documented regarding the combined use of PGPR and foliar Fe. Therefore, the current study was conducted to screen Cr tolerant PGPR and examine effect of foliar Fe with and without Cr tolerant PGPR under Cr toxicity (50 and 100 mg kg−1) in maize (Zea mays) production. Out of 15, two Cr tolerant PGPR were screened, identified (Agrobacterium fabrum and Leclercia adecarboxylata) and inoculated with 500 μM Fe. Results confirmed that Agrobacterium fabrum + 500 μM Fe performed significantly best in improving dry weight of roots and shoot, plant height, roots and shoot length and plant leaves in maize under Cr toxicity. A significant increase in chlorophyll a (51.5%), b (55.1%) and total (32.5%) validated the effectiveness of A. fabrum + 500 μM Fe to alleviate Cr toxicity. Improvement in intake of N (64.7%), P (70.0 and 183.3%), K (53.8% and 3.40-fold) in leaves and N (25.6 and 122.2%), P (25.6 and 122.2%), K (33.3% and 97.3%) in roots of maize at Cr50 and Cr100 confirmed that combined application of A. fabrum with 500 μM Fe is a more efficacious approach for alleviation of Cr toxicity and fortification of Fe comparative to sole foliar application of 500 μM Fe.

Arsenic (As) is a naturally occurring metalloid which has been recognized as a Class-1 carcinogen by the International Agency of Research on Cancer (IARC). The metalloid finds its way into the food chain through natural and anthropogenic processes. Human activities especially farming practices is a major contributor of As buildup in agricultural soils. Arsenic taken-up by the plant roots negatively affect plant productivity by disturbing various metabolic processes such as Adenosine triphosphate (ATP) formation and enzyme activation in plants. Managing As contaminated water reduces the health risks associated with As-contaminated food. The purpose of this review is to focus on the information regarding the metalloid build-up especially in the soil-plant system and ground water consider the various approaches investigated to decrease its contents and consequences on the human food chain. A critical review of the literature suggests that the contamination of the human food chain can be controlled through careful selection and application of water purification techniques with other agronomic practices.