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A total of 23 road-dust and 9 house-dust samples were collected from Alexandria and Kafr El-Sheikh cities, Egypt in 2016 to investigate heavy metal (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) contamination, spatial distribution, sources, and health risks. The mean concentrations (mg kg−1) of Cd (road-dust (RD) = 0.33, house-dust (HD) = 0.77), Cu (RD = 80, HD = 141), Pb (RD = 70, HD = 260), and Zn (RD = 169, HD = 771) in Alexandria and Zn (RD = 192, HD = 257) in Kafr El-Sheikh were higher than corresponding background (background refers to generic earth crust shale values given in the literature) levels. Whereas average concentrations (mg kg−1) of Co, Cr, Mn, and Ni (Alexandria: RD = 2.7, 24.3, 251, 14.4; HD = 3.2, 29.2, 237, 25.1 and Kafr El-Sheikh: RD = 6.6, 31.9, 343, 20.2; HD = 8.6, 33.4, 438, 23.2) in both cities were much lower than their background values. Spatially, for most heavy metals, the high concentrations were observed in areas characterized with increased anthropogenic activities, heavy traffic, and high population density. Contamination indices revealed moderate contamination (Cd and Cu) to high contamination (Pb: only house-dust from Alexandria), which posed low (most metals) to moderate ecological risk (Cd and Pb). Correlation analysis and factor analysis classified the studied metals in two groups as: natural input (Co, Cr, Mn, Ni, and Fe) and anthropogenic sources (Cd, Cu, Pb, and Zn). The noncancerous risks posed by studied metals ranged from 0.0001 (Cd) to 0.15 (Pb) and were insignificant. The cancerous risk of Pb (1.4 × 10−4) for children on exposure to house-dust form Alexandria exceeded the guideline values and was considered unacceptable, whereas the cancerous risks of other studied metals were acceptable for both subpopulations. The results of health risk revealed that children are facing higher risk than adults.

The study assessed heavy metals (Cd, Cu, Fe, Mn, Pb and Zn) and physico-chemical parameters in water, sediments and fish from an endorheic lake (Lake Chilwa) in Malawi. It was observed that pH (max. 9.7), EC (max. 2936 μS/cm), TDS (max. 2119 mg/L), NO3− (max. 6.6 mg/L) and PO43− (max. 1.3 mg/L) were higher in the dry season than in the rainy season. Pb was not detected in all samples. However, the rest of heavy metals were detected with significant values of Mn and Cu in fish (Mn: 0.015–1.18 mg/kg dry weight, dw; Cu: 0.41–0.92 mg/kg dw) and sediment (Mn: 2.25–10.66 mg/kg dw; Cu: n.d–1.63 mg/kg dw). The concentrations of heavy metals in fish samples were below the maximum limits for edible fish recommended by Food and Agriculture Organization/World Health Organization: Cd (0.1 mg/kg), Cu (3 mg/kg), Fe (43 mg/kg), Pb (0.2 mg/kg), Mn (2–9 mg/kg) and Zn (60 mg/kg). The calculated target hazard quotients (ranged from 0.001 to 1.07) indicated no human risks from fish consumption. Furthermore, dry season values for Mn, Cu and Zn in sediments were significantly higher (p

This study investigated spatio-temporal variations of selected pesticide residues in the Kurose River in Higashi-Hiroshima city (Hiroshima Prefecture), Japan. Water samples were collected from the river at seven sites every month for 1 year (March 2016 to February 2017). Pesticide residues were extracted from the samples by a solid phase extraction using Sep Pack C18 cartridges. Once extracted, the samples were analyzed for cyanazine, simetryn, fenarimol, isoprothiolane, and diazinon using a reversed-phase high-performance liquid chromatography ultraviolet visible (HPLC-UV Vis) system. The limits of detection were 3.60, 4.10, 2.80, 6.50, and 7.30 ng L-1 for cyanazine, simetryn, fenarimol, isoprothiolane, and diazinon, respectively. Good recovery rates (88%–102%), and mean percent relative standard deviation range (1.00%–5.70%) (n = 6) were obtained with a spiking at 0.20 µg L-1. The maximum concentrations of 282, 391, 60, 1086, and 1194 ng L-1 were obtained for cyanazine, simetryn, isoprothiolane,...

Although barley (Hordeum vulgare L.) is considered a salt tolerant crop species, productivity of barley is affected differently by ionic, osmotic, and oxidative stresses resulting from a salty rhizosphere. The current study was conducted to elucidate the mechanism of salt tolerance in two barley cultivars, Giza128 and Giza126. The two cultivars were exposed to 200 mM NaCl hydroponically for 12 days. Although both cultivars accumulated a large amount of Na+ in their leaves with similar concentrations, the growth of Giza128 was much better than that of Giza126, as measured by maintaining a higher dry weight, relative growth rate, leaf area, and plant height. To ascertain the underlying mechanisms of this differential tolerance, first, the relative expression patterns of the genes encoding Na+/H+ antiporters (NHX) and the associated proton pumps (V-PPase and V-ATPase) as well as the gene encoding the plasma membrane PM H+-ATPase were analyzed in leaf tissues. Salt stress induced higher HvNHX1 expression in Giza128 (3.3-fold) than in Giza126 (1.9-fold), whereas the expression of the other two genes, HvNHX2 and HvNHX3, showed no induction in either cultivar. The expression of HvHVP1 and HvHVA was higher in Giza128 (3.8- and 2.1-fold, respectively) than in Giza126 (1.6- and 1.1-fold, respectively). The expression of the PM H+-ATPase (ha1) gene was induced more in Giza128 (8.8-fold) than in Giza126 (1.8-fold). Second, the capacity for ROS detoxification was assessed using the oxidative stress biomarkers electrolyte leakage ratio (ELR) and the concentrations of malondialdehyde (MDA) and hydrogen peroxide (H2O2), and these parameters sharply increased in Giza126 leaves by 66.5%, 42.8% and 50.0%, respectively, compared with those in Giza128 leaves. The antioxidant enzyme (CAT, APX, sPOD, GR, and SOD) activities were significantly elevated by salt treatment in Giza128 leaves, whereas in Giza126, these activities were not significantly altered. Overall, the results indicate that the superior salt tolerance of Giza128 is primarily the result of the ability to counter Na+-induced oxidative stress by increasing antioxidant enzyme levels and possibly by increasing vacuolar Na+ sequestration and prevention of cellular K+ leakage.

A review of Japan’s fungicide usage from the 1960s to recent times was conducted using data from the National Institute of Environmental Studies, Japan. A total of 16 commonly used fungicides were assessed and these are: captan, chlorothalonil, fenarimol, ferbam, fosetyl-Al, iprodione, isoprothiolane, mancozeb, mepronil, metalaxyl, myclobutanil, pencycuron, thiophanate-methyl, tolclofos-methyl, triadimefon and trifloxystrobin. The assessment revealed that the most used fungicide within the period (1962–2014) was chlorothalonil with a maximum usage amount of 1795 tons/year. The least used was found to be myclobutanil with a maximum usage amount of 8 tons/year within the same reporting period. Generally, the usage of most of the fungicides peaked between the 1980s to early 2000s. For most of these fungicides, their usage amounts have decreased in recent times. However, the continuous usage of these fungicides has a potential to cause problems in the environment ranging from mere irritations to being very toxic to human beings and organisms.

A field experiment was conducted at Farm of Faculty of Agriculture, New Valley University during 2016/2017 and 2017/2018 to study the impact of some organic fertilizers (poultry, cattle , sheep manures) and mineral fertilizers under, Traditional pest control (TPC) and Integrated pest management (IPM) on growth, yield and fruit quality of tomato cv. Rawan F1. The results indicated that mineral fertilization significantly surpassed organic manures in all vegetative growth characters, yield and yield components. Organic manure treatments significantly increased fruit contents of N, P, K, Ca, Mg, vitamin C, licobin, total soluble solids and total sugars compared to chemical fertilization in both seasons. TPC followed by IPM treatment exhibited best results for all studied characters compared to control , except number of fruits/plant and unmarketable yield, fruit content of carotenoid, total phenol, total flavonoid, water content and acidity. The differences between TPC and IPM programs were insignificant for yield and its components. Furthermore, interaction between chemical fertilization and traditional program gave highest growth and yield parameters, while interaction between poultry manure and traditional program gave fruits higher chemical content compared to other interactions. Based on results, it could be recommended that fertilized tomato plants with mineral treatment under IPM gave the best yield and the highest reduction percentage of infested leaflets with T. absoluta larvae and of adult moths/trap/day, although TPC gave a slight insignificant increment in tomato yield, while soil application of composted poultry manure before tomato planting by 10.76 ton/fed, under TPC improved the quality of tomato fruits.

Polycyclic aromatic hydrocarbons (PAHs) were analyzed in road and aerial dust to assess their concentration, composition profile, distribution, emission sources, and potential human health risks. Sixteen priority PAHs and Benzo [e]pyrene (BeP) were analyzed in 13 aerial dust samples from Jalalabad, and 78 road dust samples from Kabul and Jalalabad cities, Afghanistan. The mean concentration of ∑17PAHs in road dust from Kabul and Jalalabad were 427 μg kg−1 and 288 μg kg−1, respectively whereas ∑17PAHs in aerial dust from Jalalabad averaged 200 μg kg−1. Fluoranthene (Flu), Chrysene (Chr), Benzo [b]fluoranthene (BbF), Benzo [k]fluoranthene (BkF) and BeP were major individual PAH species. The composition patterns of the PAHs were dominated by 5-6-ring PAHs (51% in road dust from Kabul; 44% in road dust from Jalalabad; and 44% in aerial dust) followed by 4-ring and 2-3-ring PAHs. Source apportionment of the road dust PAHs by the molecular diagnostic ratios (MDR) and principal component analysis (PCA), indicated signatures of PAHs sources (including vehicular exhaust, coal/wood combustion and oil spill). The Benzo [a]pyrene (BaP) toxicity equivalent values (BaPeq17PAHs) for road dust were 75 μg kg−1 (Kabul) and 36 μg kg−1 (Jalalabad); and 35 μg kg−1 for aerial dust (Jalalabad). BaP and Dibenz [a,h]anthracene (DahA) together contributed > 50% of the BaPeq associated cancer risk. All incremental lifetime cancer risk (ILCR) due to human exposure to road and aerial dust PAHs were in the order of 10−7, which is one-fold lower than the threshold (10−6). The noncancerous risk (Hazard Index

A study was conducted to characterize marigold stress response to polycyclic aromatic hydrocarbons (PAHs) (oxidative stress inducers) with and without sulfuric acid (S.Acid; pH 3) (acid-stress inducer), and to evaluate reactive oxygen species (ROS) scavenging activity of mannitol (Mann). Marigold (Calendula officinalis) seedlings were grown in a greenhouse and fumigated with fluoranthene (FLU), phenanthrene (PHE), Mann, and S.Acid individually and in various combinations for 40 days. Various physiological and biochemical parameters among others were analyzed using standard methods. The results revealed that fumigation of FLU induced oxidative stress to the plants via ROS generation leading to negative effects on photosynthesis at near saturating irradiance (Amax), stomatal conductance (Gs), internal carbon dioxide concentration (Ci), leaf water relations and chlorophyll pigments. Significant per cent inhibition of Amax (54%), Gs (86%) and Ci (32%), as well as per cent reductions in chlorophyll a (Chl.a) (33%), Chl.b (34%), and total chlorophyll (Tot. Chl) (48%) contents were recorded in FLU fumigated treatment in comparison to control. Combination of Mann with FLU scavenged the generated ROS and substantially lowered the oxidative stress on the plants hence all the measured parameters were not significantly different from control. PHE fumigation had varied effects on marigold plants and was not as deleterious as FLU. Combined fumigation of S.Acid with both the PAHs had significant negative effect on leaf water relations, and positive effect on fresh and turgid weight of the plants but had no effect on the other measured parameters. The lowest proline contents and highest catalase and ascorbate peroxidase activities in FLU fumigated plants further confirmed that oxidative stress was imposed via the generation of ROS. From the results, it is evident that Mann could be an efficient scavenger of ROS-generated by FLU in the marigold plants. We recommend Mann to be widely used for the protection of higher plants from FLU-generated stress in the urban areas.

This study was designed to investigate selected road-dust associated heavy metals, their relations with natural and anthropogenic sources, and potential human and environmental health risks. For this purpose, 42 and 36 road-dusts samples were collected from Jalalabad and Kabul cities (Afghanistan), respectively. The following elements were found in descending concentrations: Mn, Zn, Pb, Ni, Cu, Cr, Co, and Cd in Jalalabad; and Mn, Zn, Ni, Cu, Cr, Pb, Co, and Cd in Kabul. Except for Ni, all the elemental contents were less than the Canadian permissible limits in residential/parkland soils. Principle Component Analysis and enrichment of Cd, Cu, Ni, Pb, and Zn pointed to anthropogenic sources, whereas Co, Cr, and Mn indicated crustal inputs. Broadly, Cd monomial risk index ( $$E_{r}^{i}$$ ) was considerable; however, one site each in both cities showed high risk ( $$E_{r}^{i}$$ ≥ 350). The potential ecological risk (RI) is mostly low; however, at some sites, the risk was considerable. Ingestion appeared to be the main exposure route (99%) for heavy metals and contributed > 90% to noncancerous (all residents), as well as 92% (children) and 75–89% (adults) cancerous risks. The noncancerous risks of all metals and their integrated risks for all residents were within acceptable levels. Moreover, potential cancer risks in children from Ni and Cr were slightly higher than the US-EPA safe levels but were within acceptable levels for adults. This study found higher risks to children and therefore recommends proper management and ways to control metals pollution load in these areas to decrease human health and RIs.