High Concentrations Of Atrazine Research Articles

Leaching of Nitrate, Atrazine, and Metribuzin from Sugarcane in Southern Louisiana

AbstractWe have studied the leaching losses of NO3, atrazine [6‐chloro‐N‐ethyl‐N′‐(1‐methylethyl)‐1,3,5‐triazine‐2,4‐diamine], and metribuzin [4‐amino‐6‐(1,1‐dimethylethyl)‐3‐(methylthio)‐1,2,4‐triazine‐5(4H)‐one] applied to sugarcane (Saccharum officinarum L.) planted in Mississippi River alluvial soil in southern Louisiana. Nitrogen (122 kg/ha) and atrazine (2.24 kg/ha) were applied in June, and atrazine (2.24 kg/ha) and metribuzin (1.12 kg/ha) were applied in December; losses through a Sharkey clay (very fine, montmorillonitic, nonacid, thermic Vertic Haplaquepts) into subsurface drains (5.5‐ and 10.9‐m spacing) were measured for about 100 d in both seasons. Five days after application NO3‐N appeared in its highest concentrations (5–11 mg/L) in the drain water; after this first event, concentrations remained below 10 mg/L throughout the summer season. After application in the summer atrazine appeared in the subsurface drains at its highest seasonal concentrations (114–144 µg/L) on the day of application; after 4 to 7 wk these concentrations remained below 3.0 µg/L. Total losses in the summer amounted to 3 to 8% of the NO3 application and 0.6 to 1.2% of the atrazine application. Almost 50% of the NO3 leaching into the subsurface drains occurred after Day 76, whereas 82% of the atrazine leached into the drains by Day 8. After the winter application, high concentrations of atrazine (67–81 µg/L) and metribuzin (52–94 µg/L) were measured within 8 d. Similarly, large concentrations of atrazine occurred in the drain water throughout the winter season. The much higher concentrations of atrazine during the winter study, compared with the summer, coincided with soil surface concentrations that were 3 to 10 times those of the summer. Total losses during the winter were 0.4 to 2.0% (atrazine) and 0.4 to 1.7% (metribuzin) of the applications. Evidence for preferential flow into the drains of the NO3 and the herbicides is presented.

Field Study of the Effect of Sewage Sludge Application on Atrazine Behaviour in Soil

Abstract Atrazine dissipation was followed in a hydromorphic soil and a loamy soil amended with different kinds of sewage sludge. The atrazine was applied 5 months after the organic amendments. The hydromorphic soil was drained and water samples were collected for atrazine analyses. The atrazine dissipation was slower in the plot amended with sewage sludge, but after 12 months, non significant differences were found between the control plot and the amended plot. The highest concentrations of atrazine and metabolites were found in the water drained from the control plot, and the biodegradation degree, estimated from the deethylatrazine to atrazine ratio, was higher than in the amended plot. In the loamy soil, the dissipation kinetics were similar for all the sewage sludges; however, significant differences were found in the distribution of the atrazine residues with depth.

Predicting atrazine adsorption‐desorption in soils: A modified second‐order kinetic model

Atrazine retention on a Sharkey clay soil was quantified using a kinetic batch method for different soil to solution ratios. Time‐dependent adsorption‐desorption was also measured using a batch method with successive dilution steps. Adsorption was found to be highly kinetic in nature. In addition, adsorption‐desorption isotherms exhibited a strong hysteretic behavior. The extent of observed hysteresis increased with retention time. Attempts were made to describe atrazine retention based on a modified second‐order approach where heterogeneity of adsorption sites was assumed. Two retention sites were considered: type 1 (Se) represented that retained on noncatalytic sites with low binding energy, and type 2 (Sk) was that retained on catalytic sites and form strong interactions with matrix surfaces. A third type (Si) represented irreversible sites occupied by hydroxyatrazine following hydrolysis or other physical/chemical transformations. The rates of reactions were assumed as a function of vacant or available sites which were equally accessible to either Se or Sk. A direct method to quantify the adsorption capacity (ϕm) as a measure of the total retention sites by maintaining high atrazine concentrations in soil solution was not successful. However, the use of an indirectly estimated ϕm along with nonlinear least squares adequately described kinetic retention results. Based on least square best fit, model parameters were independent of initial concentrations (Ci) and an overall set of parameters was capable of describing an entire data set for all Ci. The model was also successful in predicting atrazine retention for a different data set and for all Ci using one set of model parameters which were obtained independently from another data set. Further application of the model was to test whether these independently estimated model parameters can predict the kinetics of adsorption‐desorption hysteresis. Unlike other approaches where adsorption and desorption isotherms were separately described, the second‐order model was capable of describing both adsorption and desorption kinetics. Improved hysteresis predictions were observed when model parameters were derived from experiments of simuar conditions.

Organonitrogen herbicides in the lower Kansas River basin

Atrazine, which is not readily removed by conventional treatment, may cause problems for water utilities in agricultural areas.To help managers, planners, and regulators determine when and where surface waters are likely to be adversely affected by organonitrogen herbicides, the authors analyzed various data on the distribution of these compounds in the lower Kansas River basin. They found that atrazine was the most frequently detected herbicide, was found in the highest concentrations, and was most likely to exceed the maximum contaminant level. The highest atrazine concentrations in the water were measured where the largest amounts of atrazine had been applied to the land, and median concentrations were higher in spring and summer than in fall and winter. Atrazine and chemically similar herbicides are not effectively removed by traditional water treatment. The Kansas State Board of Agriculture has established a pesticide management area to decrease the amount of atrazine that enters surface water.

Integrated Soil, Crop and Water Management System to Abate Herbicide and Nitrate Contamination of the Great Lakes

Corn management practices, incorporating annual ryegrass intercrop, conservation tillage and water table management, were evaluated to reduce herbicide and N0−3 losses through surface runoff and tile drainage. The integrated management system being developed at Harrow in S.W. Ontario reduced herbicide input 50% by banding the chemical over the seed row. Runoff events close to herbicide application contained high concentrations of atrazine, metribuzin and metolachlor. However, the volume of runoff was low during the 1991 growing season, therefore herbicide loss was low (<2% of applied). The three herbicides rapidly dissipated in the soil so that subsequent runoff events transported little herbicide in the runoff water. The total quantity of de-ethyl atrazine loss was lower from soil saver than moldboard plow. No water table control or intercrop effects were found in 1991 for herbicide loss because of the drought Tile drainage resulted in a greater volume of water and loss of N0−3 than with surface runoff. Consequently, over 97% of the total N0−3 loss occurred through tile drainage. The flow weighted N0−3 concentration in tile drainage water was 22.5 mg N L−1 for the drainage treatments and 15.1 mg N L−1 for the water table control treatments from Nov. 1, 1991 till April 30, 1992. During this time period, N0−3 loss through tile drainage was 57.8 kg N ha−1 from the drainage treatments and 36.3 kg N ha−1 from the water table control treatments. Therefore, the water table control treatment reduced the flow weighted N0−3 concentration in tile drainage water by 33% and total N0−3 loss by 37%. The water table control treatments combined with soil saver tillage resulted in lower concentrations and losses of N0−3 than with any other treatments.

Atrazine contamination of groundwaters in eastern France in relation to the hydrogeological properties of the agricultural land

Abstract In Alsace, groundwater contamination by atrazine has been studied on a seasonal basis at 6 sampling sites (5 groundwater wells and a river) covering an agricultural area of approximately 32 km2 where corn has been cultivated intensively for the previous 10 years. Three atrazine ‐ treated fields have also been analysed in order to follow the seasonal variations of the pesticide concentration in the soil following the annual treatment. During the three years of this study (May 1990 to August 1992), high atrazine concentrations (exceeding 0.2 μg 1‐1) were detected at all sites studied with higher concentrations present at the beginning of summer. Some of the sites were contaminated with atrazine at concentrations ranging from 250 μg 1‐1 to 1500 μg 1‐1. The contamination of a river, for which the main sources are groundwater and drainage water, by this herbicide reflects the events occurring in sub‐surface water. Atrazine concentrations reached 0.6 to 2.0 μg 1‐1 during the critical months (May to Jun...

Tolerance of Cultured Amaranthus retroflexus Cells to Atrazine

Resistance to s-triazine-herbicides in weeds is the most widespread and extensively studied of all intraspecific herbicide-resistance. It is of interest that the resistant biotype appears in some limited genera such as Amaranthus spp. and Chenopodium spp. much more frequently than in many other significant weeds. We examined the response of cultured Amaranthus retroflexus cells to atrazine in comparison with those of several other plant species to understand what causes this differentially inter-specific response. Atrazine scarcely inhibited the cell growth of either atrazine-resistant and susceptible-Amaranthus cells. Tobacco cells, however, could not grow as cultured Amaranthus cells in high concentrations of atrazine even under heterotrophic culture conditions. Atrazine-resistant tobacco cells were also sensitive to high concentrations of atrazine. The inhibition of cell growth by this secondary effect of atrazine was also observed in cultured wheat and rice cells. Atrazine-sensitive Chenopodium cells are relatively more resistant to high concentrations of atrazine. The importance of potential tolerance to the secondary effects of atrazine is discussed with respect to the frequent occurrence of triazine- resistant biotypes in limited plant species.

Bioconcentration of atrazine in the banded tilapia, Tilapia sparrmanii

1. The bioconcentration of atrazine was determined in the liver, muscle, heart, gonads and brain of Tilapia sparrmanii exposed to high concentrations of atrazine. 2. The highest concentrations were recorded in the ovaries (50.6 μg/g) and in the liver (40.1 ± 5.5 μg/g). This may be attributed to the higher lipid content of these organs, while the liver also accumulates atrazine as a result of its detoxification function. 3. The bioaccumulation factors for atrazine in the liver, muscle, heart, gonads and brain ranged from 0.9 to 20.0. Bioconcentration of atrazine in banded tilapia was found to be low, even after exposure to external atrazine concentration much higher than detected in natural surface water.

Comparison of enzyme-linked immunosorbent assay and high-performance liquid chromatography for the analysis of atrazine in water from Czechoslovakia

Twenty-two water samples from Bohemian Paradise in Czechoslovakia were analyzed for atrazine (2-chloro-4-ethylamino-6- isopropylamino-1,3,5-triazine) by enzyme immunoassay (EIA) and high-performance liquid chromatography (HPLC). Three samples were drinking water, the others were creek water. The amount of atrazine found by EIA ranged from 0.2 to 12,700 ng/ml and 0.10 to 10,300 ng/ml by HPLC. Agreement between the methods was good. Nine samples containing the highest concentrations of atrazine were used to check the day-to-day reproducibility of both methods at high atrazine levels. The percent coefficients of variation (% CVs) ranged from 5.9 to 26.2 for the EIA and 1.5 to 33.2 for the HPLC. Day to day % CV values for each calibrator concentration ranged from 5.7 to 10.9 for EIA and 9.9 to 13.9 for HPLC. Sensitivity of the EIA was 0.2 ng/ml while it was 0.1 ng/ml for solid phase extraction HPLC and slightly less than 60 ng/ml for direct injection HPLC.

Selection of atrazine-resistant tobacco variants from photomixotrophic cultures

Abstract Photomixotrophic cell cultures of Nicotiana tabacum L. (cv. Wisconsin 38) were established and used to select atrazine resistant variants. Thirty-seven plants were regenerated and rooted in the presence of atrazine from clonal cell lines selected for resistance. Variants showed variability in pollen viability, leaf shape and size, plant height, seed set and floral structure. Most morphological abnormalities were associated with chromosomal abnormalities and an increased frequency of chromosomal abnormalities were associated with higher atrazine concentrations in the selection media. Herbicide binding to chloroplast thylakoid membranes, oxygen evolution, leaf disk bleaching and leaf disk callusing were used as assays to determine resistance levels to atrazine in selected variants. The first two methods appeared to be the more accurate means of determining atrazine resistance. Some variability may be attributed to differences in physiological maturity, somaclonal variation, or to the sorting out of resistant and susceptible chloroplast populations.

Interaction of the herbicide atrazine with model membranes. II: Effect of atrazine on fusion of phospholipid vesicles

The effect of atrazine on Ca 2+ induced fusion of cardiolipin(CL) and phosphatidylserine (PS) vesicles is studied by Tb 3+/dipicolinic acid fluorescence and turbidity measurements. The interaction of herbicide with CL and PS membranes is studied by DPH fluorescence polarization. At low concentrations the pesticide partially inhibits fusion, especially in CL vesicles. Higher concentrations of atrazine decrease inhibition of fusion in CL, while fusion is slightly increased in PS. The Ca 2+-induced increase of turbidity is not affected by atrazine in both PS and CL aggregation experiments. DPH polarization measurements show a perturbation only of the membrane hydrophobic core of PS, in presence of Ca 2+. It is hypothesized that this biphasic effect shown by low and high atrazine concentrations on Ca 2+-induced fusion of vesicles is due to a different localization of the pesticide in the membrane.

Effect of Atrazine and Tillage on Alfalfa (Medicago sativa) Establishment in Corn (Zeaways)-AlfaIfa Rotation

The effect of atrazine rate and subsequent tillage on seedling alfalfa injury from atrazine carry-over was examined at two locations in Michigan. Atrazine concentration and alfalfa injury 1 yr after treatment were greater in the northern location than in the central Michigan location. At both locations, alfalfa injury was significantly greater under no-tillage than moldboard plowing. With no-tillage, alfalfa was injured more in the area between the previous corn rows than within the rows. Analysis of soil samples collected from within corn rows and between rows showed higher atrazine concentration between the corn rows.

Contamination of groundwater by atrazine and selected metabolites

Groundwaters from an agricultural PA watershed were analyzed for atrazine, cyanazine, simazine, and the desethylated (DEA), and desisopropylated (DIA) atrazine metabolites. Atrazine and both metabolites were found in most groundwaters including deep wells, a spring and groundwaters about to become streamflow. The highest concentrations of atrazine and the dominant metabolite, DEA, were found in groundwaters draining areas dominated by corn production, especially after the first major groundwater recharge period following herbicide application.

Nature and extent of groundwater contamination by pesticides in an agricultural watershed

Waters from 21 wells and two springs located in a typically farmed, mostly agricultural Pennsylvania watershed were analyzed for 11 pesticides, NO 3, Cl and PO 4. Among the pesticides selected according to a farm use survey, only atrazine was commonly found but at extremely low concentrations ranging from 3 ng/l to 1.11 μg/l. Atrazine appeared in 74% of cropland wells at least once in a three sampling sequence designed to sample several major groundwater recharge periods. No alachlor, metolachlor, carbofuran, terbufos, chlorpyrifos, or fonofos was found. Cyanazine was found intermittently in two wells. With only one record of application, simazine was found at least once in 32% of the cropland wells, but at extremely low concentrations. Neither 2,4-D nor dicamba were found in the one sampling analyzed. The frequency and extent of corn production expressed as Corn Production Intensity (CPI) was strongly related to atrazine concentrations. The highest atrazine concentrations were nearly always associated with continuous corn production. Atrazine concentrations over time varied greatly by well and followed several distinct patterns. Sampling time relative to major groundwater recharge periods affected these concentrations, but a predictive relationship was not apparent.

Effects of atrazine on freshwater microbial communities.

A multispecies toxicity test system using naturally derived microbial communities on polyurethane foam substrates was used to evaluate the toxic effects of the herbicide atrazine. Both structural (e.g., protozoan species number, biomass) and functional (e.g., colonization rate, oxygen production) community responses were measured. Oxygen production and the ability of communities to sequester magnesium and calcium were the most sensitive measures of toxic stress due to atrazine (maximum allowable toxicant concentrations [MATCs]=17.9 μg/L). Dissolved oxygen was 33% lower, and there was 15% less calcium and magnesium in communities at and above 32.0 μg/L atrazine compared to controls. Species richness and estimates of biomass (total protein and chlorophyll a) were less sensitive (MATCs=193) to atrazine. At the highest atrazine concentration (337 μg/L), species numbers were 30% lower than controls, and protein and chlorophyll a content of communities were reduced by 38 and 91%, respectively. Low levels of atrazine (3.2–32.0 μg/L) resulted in a 46% increase in species numbers and a greater concentration of total protein and chlorophyll a (41 and 57%, respectively). Results compared well with other estimates of chronic toxicity for effects of atrazine on aquatic communities. Reported MATCs ranged from 70.7 to 3,400 μg/L. The results from this test emphasize the importance of monitoring both structural and functional measures of community integrity in toxicity testing with multispecies.

Pesticide Contamination of Groundwaters in the Mahantango Creek Watershed

AbstractWaters from 20 wells in a primarily agricultural Pennsylvania watershed were analyzed for the most heavily and extensively applied pesticides as determined by farm survey. Those analyzed were atrazine, metolachlor, cyanazine, alachlor, terbufos, chlorpyrifos, fonofos, and carbofuran. No metolachlor, alachlor, terbufos, chlorpyrifos, fonofos, or carbofuran were detected. However, atrazine concentrations ranging from 13 to 1110 ng/L were found in 14 of the 20 wells. These findings suggest widespread atrazine contamination of the groundwaters, but at extremely low concentrations. Cyanazine was found above trace concentrations in one well. Although there was only one record of application, simazine was found in seven wells within the range of 10 to 170 ng/L. The degree and spatial distribution of atrazine contamination depended mostly on the frequency and distribution of corn production. The highest atrazine concentrations were associated mostly with continuous corn production. Aquifer rock type, depth to water table, and the degree of recharge short‐circuiting estimated from PO4 contamination of groundwater, were concluded not to be important factors. Generally, Cl provided a better index of atrazine contamination than did NO3 because extensive denitrification occurred in several wells. The probability of atrazine being found above the minimum detection limit was high when Cl exceeded 3 mg/L or NO3‐N exceeded 4 mg/L.

Accumulation of pollutants in fish

1. 1. The amount of radioactivity which derived from 14C-labeled pollutants was determined in liver, kidney, intestine, blood, muscle and gills of carp, exposed for 6, 24 and 72 hr to high external concentrations of urea, methanol, atrazine and PCP. 2. 2. The results allowed one to calculate roughly the uptake rate for these compounds. It was low for urea (0.055 μg/g per hr), higher for methanol (0.12) and atrazine (0.16) and highest for PCP (1.5). 3. 3. The bioaccumulation factors (BFs) were determined for the different substances and organs. They correlated with the hydrophilic-lipophilic nature of the chemicals. The more lipophilic the substances the more accumulation occurred in the liver. 4. 4. PCP accumulated the most. BF was 300–400 in most tissues except muscle where it was quite low. The BF was 3–4 for atrazine in liver, kidney and intestine, but just 1 in blood, muscle and gills. 5. 5. There is some evidence that the BF for methanol equals 1 in liver, kidney, gills and intestine. It is less than 1 in blood and muscle. Urea was equally distributed in all organs and in the external medium.

Atrazine residues in estuarine water and the aerial deposition of atrazine into Rhode River, Maryland

Water samples from the Rhode River, an estuary situated on the western shore of the Chesapeake Bay, were analyzed for atrazine residues twice a week for 2 yr. Precipitation samples; which included dryfall, rainfall, and snowfall were collected with wide-mouth stainless steel collection pans situated about 20 m above ground in an open space. A total of 68 precipitation samples was collected from December 1976 to February 1979. Atrazine residues were detectable in estuarine water and in rainwater year-round. Atrazine residues in estuarine water were generally 6 to 190 ng 1−1 atrazine residues in rainwater (bulk precipitation) were 3 to 2190 ng 1−1. Atrazine residues in rainwater samples collected during the winter season (January to April 1977) were unexpectedly high (e.g., 3 to 970 ng 1−1). The highest atrazine concentration of 2190 ng 1−1 was detected from a 0.76 cm rainfall event collected on May 19, 1977. Intermittent spraying operations of atrazine within the cornfields were generally done during May of each year. Rain samples collected during May of 1978 also showed higher atrazine residues than the rest of the 1978 growing season, but at levels much less than those detected in 1977 rainwater. Although high atrazine concentrations were detected in winter rainfall, these did not result in similarly higher atrazine concentrations in estuarine receiving waters. Our data showed a decline of atrazine concentrations in estuarine water in October and November which continued until a rainfall following Spring herbicide applications. Atrazine is enriched at the microsurface layer of estuarine water, but direct atmospheric input of atrazine did not seem to contribute significantly to the enrichment mechanism. Atrazine is believed to be transported long distances in polluted air masses. The estuarine microsurface layer could be a source of atmospheric atrazine, but the importance of the source is yet to be determined. Atrazine was quantitatively determined by GC using a nitrogen specific electrolytic detector and was confirmed by GC/Mass.

Transport of Atrazine and Simazine in Runoff from Conventional and No‐Tillage Corn

AbstractOn 0.4‐ to 3.5‐ha watersheds, highest concentrations of atrazine (0.48 ppm) (2‐chloro‐4‐[ethylamino]‐6‐[isopropylamino]‐s‐triazine) and simazine (1.2 ppm) (2‐chloro‐4,6‐bis[ethylamino]‐s‐triazine) were present in runoff occurring soon after application and declined rapidly for later events. Quantity of herbicides transported increased with the amount of runoff, and was inversely related to the length of time between application and the runoff event. A maximum of 6% of the applied herbicide was transported from the field even under the most favorable conditions, and the average for all watersheds was < 2%. Less runoff and herbicide loss occurred from areas planted to no‐tillage than to conventional corn (Zea mays L.).In a multiple regression analysis of the factors, the natural logarithm (ln) of days after application and a tillage × application rate interaction were useful in predicting the natural logarithm of herbicide concentration in runoff. Factors from the multiple regression analysis used in this study were important in predicting concentration of atrazine and other pesticides when applied to data published by other workers.

Some Effects of Triazines on Growth, Photosynthesis and Translocation of Photosjuthate in Pinus Species

AbstractThe effects of triazines on growth, 14CO2‐fixation and translocation of 14C‐assimilates by young Pinus seedlings were investigated. Post‐emergenceroot application of moderate and high concentrations of simazine and atrazine resulted in severe toxicity to the seedlings of Pinus nigra and P. coniorta as depicted by reduction in dry weight, chlorosis, wilting and mortality. Atrazine was more toxic than simazine and P. nigra was more susceptible than P. contorta to both the triazines. Simazine treatment to the roots of P. nigra seedlings, not only caused inhibition of 14CO2‐fixation but also reduced the short‐term downward transloca‐tion of l4 C‐assimilates. Various possible mechanisms whereby simazine reduced the downward movement of I4C‐assimilates in Pinus seedlings are discussed.