Environmental risk assessment of genetically engineered herbicide-tolerant Zoysia japonica

Herbicide-tolerant Zoysia grass (Zoysia japonica Steud.) has been generated previously through Agrobacterium tumefaciens-mediated transformation. The genetically modified (GM) Zoysia grass survived Basta spraying and grew to maturity normally while the wild-type (WT) grass stopped growing and died. GM Zoysia grass will permit more efficient weed control for various turf grass plantings such as home lawns, golf courses, and parks. We examined the environmental/biodiversity risks of herbicide-tolerant GM Zoysia before applying to regulatory agencies for approval for commercial release. The GM and WT Zoysia grass' substantial trait equivalence, ability to cross-pollinate, and gene flow in confined and unconfined test fields were selectively analyzed for environmental/biodiversity effects. No difference between GM and WT Zoysia grass in substantial traits was found. To assess the potential for cross-pollination and gene flow, a non-selective herbicide, Basta, was used. Results showed that unintended cross-pollination with and gene flow from GM Zoysia grass were not detected in neighboring weed species examined, but were observed in WT Zoysia grass (on average, 6% at proximity, 1.2% at a distance of 0.5 m and 0.12% at a radius of 3 m, and 0% at distances over 3 m). On the basis of these initial studies, we conclude that the GM Zoysia grass generated in our laboratory and tested in the Nam Jeju County field does not appear to pose a significant risk when cultivated outside of test fields.     

Transformations,Lifetimes, and Sources of NO2, HONO,and HNO3 in Indoor Environments

Recent research has demonstrated that nitrogen oxides are transformed to nitrogen acids in indoor environments, and that significant concentrations of nitrous acid are present in indoor air. The purpose of the study reported in this paper has been to investigate the sources, chemical transformations and lifetimes of nitrogen oxides and nitrogen acids under the conditions existing in buildings. An unoccupied single family residence was instrumented for monitoring of NO, NO₂, NO_y, MONO, HNO₃, CO, temperature, relative humidity, and air exchange rate. For some experiments, NO₂ and HONO were injected into the house to determine their removal rates and lifetimes. Other experiments investigated the emissions and transformations of nitrogen species from unvented natural gas appliances. We determined that HONO is formed by both direct emissions from combustion processes and reaction of NO₂ with surfaces present indoors. Equilibrium considerations influence the relative contributions of these two sources to the indoor burden of HONO. We determined that the lifetimes of trace nitrogen species varied in the order NO ~ HONO > NO₂ >HNO₃. The lifetimes with respect to reactive processes are on the order of hours for NO and HONO, about an hour for NO₂, and 30 minutes or less for HNO3. The rapid removal of NO₂ and long lifetime of HONO suggest that HONO may represent a significant fraction of the oxidized nitrogen burden in indoor air.     

Examining the relationship between metal exposure (Cd and Hg), subcellular accumulation,and physiology of juvenile Crassostrea virginica

Environmental Science and Pollution Research - To assess the toxicity and accumulation (total and subcellular partitioning) of cadmium (Cd) and mercury (Hg), juvenile eastern oysters, Crassostrea...     

Chemical Changes in Agricultural Soils of Korea: Data Review and Suggested Countermeasures

The monitoring of chemical properties, including heavy metals, in soils is necessary if better management and remediation practices are to be established for polluted soils. The National Institute of Agricultural Science and Technology initiated a monitoring study that investigated fertility and heavy metal contents of the benchmarked soils. The study covered paddy soils, upland soils, and horticultural soils in the plastic film houses, and orchard soils throughout the Korea from 1990 to 1998. Likewise,4047 samples of paddy and 2534 samples of plastic house in 1999 and 2000 were analyzed through the Soil Environment Conservation Act. Soil chemical properties such as pH, organic matter, availablephosphate and extractable calcium, magnesium and potassium contents, and heavy metal contentssuch as cadmium, copper, lead, zinc, arsenic, mercury, and cobalt contents were analyzed. The studyshowed that the average contents of organic matter, available phosphate, and extractable potassiumrapidly increased in plastic house soils than in upland or paddy soils. Two kinds of fertilizer recommendation systems were established for the study: the standard levels by national soil average data for 77 crops and the recommendation by soil test for 70 crops. Standard nitrogen fertilizer application levels for cereal crops changed from 94 kg/ha in 1960s, 99 kg/ha in 1970s, 110 kg/ha in 1980s to 90 kg/ha in 1990s. The K₂O-fertilizer also changed from 67 kg/ha in 1960s, 76 kg/ha in 1970s, 92 kg/ha in 1980s, andonly 44 kg/ha in 1990s. In rice paddy fields, the average contents of Cd, Cu, Pb, and Zn in surface soils(0–15 cm depth) were 0.11 mg kg^–1(ranged from 0 to 1.01), 4.70 mg kg^–1(0–41.59), 4.84 mg kg^–1(0–66.44), and 4.47 mg kg^–1(0–96.70), respectively. In the uplands, the average contents of Cd, Cu, Pb, Zn,and As in surface soils (0–15 cm depth) were 0.135 mg kg^–1(ranged from 0 to 0.660), 2.77 mg kg^–1(0.07–78.24), 3.47 mg kg^–1(0–43.00), 10.70 mg kg^–1(0.30–65.10), and 0.57 mg kg^–1(0.21–2.90), respectively. In plastic film houses, the average contents of Cd, Cu, Pb, Zn, and As in surface soil were 0.12 mg kg^–1(ranging from 0 to 1.28), 4.82 mg kg^–1(0–46.50), 2.68 mg kg^–1(0–46.50), 31.19 mg kg^–1(0.19–252.0), and 0.36 mg kg^–1(0–4.98), respectively. In orchard fields, the averagecontents of Cd, Cu, Pb, Zn, As, and Hg in surface soils (0–20 cm depth) were 0.11 mg kg^–1(ranged from 0–0.49), 3.62 mg kg^–1(0.03–45.30), 2.30 mg kg^–1(0–27.80), 16.60 mg kg^–1(0.33–105.50),0.44 mg kg^–1(0–4.14), and 0.05 mg kg^–1(0.01–0.54), respectively. For polluted soils with over thewarning content levels of heavy metals, fine red earth application, land reconsolidation and soilamelioration such as lime, phosphate, organic manure, and submerging were recommended. For the countermeasure areas, cultivation of non-edible crops such as garden trees, flowers, and fiber crops; landreformation; and heavy application of finered earth (up to 30 cm) were strongly recommended. Landuse techniques should be changed to beharmonious with the environment to increase yield andincome. Soil function characteristics should betaken into account.     

Analysis of chlorinated paraffins in cutting fluids and sealing materials by carbon skeleton reaction gas chromatography

Chlorinated paraffins (CPs) pose a major risk in the environment, due to their wide application, to their persistence, to their carcinogenic potential, and in view of the fact, that they cannot be easily identified. Various commercial cutting fluids and sealing materials were analysed for CPs with carbon skeleton reaction gas chromatography (GC) and flame ionization detection. CPs are simultaneously dechlorinated and hydrogenated to the corresponding alkanes with Pd catalyst material in the GC injector. With this method, the carbon chain length of commercial technical CPs was determined. In six of sixteen sealing materials we found five short and one medium chain length polychlorinated paraffins in percentages of 9-16% (w/w). In five cutting fluids we found predominantly medium to long chain length chloroparaffins with percentages of 2.5-31% (w/w), only one fluid contained short chain CPs.     

Use of three monitoring approaches to manage a major <Emphasis Type="Italic">Chrysosporum ovalisporum</Emphasis> bloom in the Murray River,Australia, 2016

An unusual bloom of Chrysosporum ovalisporum (basionym Aphanizomenon ovalisporum) occurred for the first time in the Murray River and distributary rivers in New South Wales, Australia, from mid-February to early June 2016. At its greatest extent, it contaminated a combined river length of ca. 2360 km. Chrysosporum ovalisporum usually comprised >99% of the total bloom biovolume at most locations sampled, which at times exceeded 40 mm³ l^?1. The origins of the bloom were most likely reservoirs on the upper Murray River, with cyanobacterial-infested water released from them contaminating the river systems downstream. An integrated approach using three analytical methods: (1) identification and enumeration by microscopy, (2) multiplex quantitative polymerase chain reaction (qPCR), and (3) toxin analysis, was used to obtain data for the assessment of risk to water users and management of the bloom. qPCR indicated some cyrA and stxA genes responsible for cylindrospermopsin and saxitoxin biosynthesis respectively were present, but mostly below the level of quantification. No mcyE genes for microcystin biosynthesis were detected. Toxin analysis also revealed that cylindrospermopsin, saxitoxin and microcystin were all below detection. Lack of measurable toxicity in a species usually considered a cylindrospermopsin producer elsewhere meant the possibility of relaxing management guidelines; however, high (Red) alerts needed to be maintained due to risk to water users from other biohazards potentially produced by the cyanobacteria such as contact irritants. A three-tiered monitoring strategy is suggested for monitoring cyanobacterial blooms to provide enhanced data for bloom management.     

Identification of potential biomarkers for diazinon exposure to Japanese Medaka (Oryzias latipes) using annealing control primers

A new differential display-polymerase chain reaction (PCR) method based on annealing control primers was used to screen and identify potential biomarkers from differentially expressed genes (DEGs) in medaka exposed to sub-lethal concentration of diazinon (100 ppb). Among the differentially expressed genes identified, the majority were in functional categories of protein biosynthesis, transport and metabolism according to the gene ontology classification. The differential expression of ribosomal protein genes was quantified by real time PCR. The genes encoding ribosomal proteins including L3 and S17 were selected as potential biomarkers for diazinon exposure in medaka fish.