NH3 Toxicity Research Articles

Short-Term Toxicity of NH3 and Low Oxygen to Benthic Macroinvertebrates of Running Waters and Conclusions for Wet Weather Water Pollution Control Measures

The short-term toxicity of NH3 and low oxygen was determined for different species of aquatic insects (mayflies and stoneflies). The experiments were carried out in laboratory channels. Compared with fish species, the investigated macroinvertebrates were much less sensitive. Hence, if ecotoxicological criteria for the wet weather situation are developed for ammonia and oxygen, the requirements of sensitive fish species should be considered first. In Switzerland, exceedences of the NH3 short-term threshold concentration caused by combined sewer overflow occur mostly in (too) small receiving waters during summer thunderstorms.

Effect of Injected Liquid Beef Manure on Soil Chemical Properties and Corn Root Distribution

Concentrated bands of liquid manure resulting from knife injection may be responsible for documented corn (Zea mays L.) production problems including uneven corn growth, plant yellowing, and lack of corn roots in the manure zone. Soil injected with liquid beef manure was incubated to determine effects on soil chemical properties, soil atmosphere composition, and corn root growth and distribution in or near the manure zone. An equivalent field injection rate of 3000 gal manure/acre was introduced into a 2.5 in. diameter circular band in boxes filled with Derinda silt loam (fine, mixed, mesic Typic Hapludalf) soil. Corn roots did not grow in the manure zone for 26 d after manure application. Chemical transformations found within and at 1.5 in. (from the manure center) below and beside the manure zone indicated possible toxic conditions to root growth. These included: reducing conditions, as indicated by low Eh, high moisture content, and low O2 concentration in the soil atmosphere (plus the presence of CH4) for 28 d after application; NH3 toxicity, as indicated by high concentrations of NH4−N and high pH for 21 d; and accumulation of high concentrations of NO2−N from 14 to 35 d after application. Only limited effects on soil chemical properties and root growth were found beyond 1.5 in. from the center of the manure zone. These results provide plausible explanations for corn growth problems associated with knife injected liquid manure.

The acute and chronic toxicity of ammonia to marine fish and a mysid

The acute toxicity (96-hr LC50) of un-ionized ammonia to mysids (Mysidopsis bahia) and larval inland silversides (Menidia beryllina) was influenced by pH and salinity in a species specific manner. With mysids, NH3 was most toxic at pH 7.0 and less toxic at pH 8.0 and 9.0. In contrast, NH3 toxicity to inland silversides was greatest at pH 7.0 and 9.0 and lowest at pH 8.0. A drop in salinity from 31 g/kg to 11 g/kg uniformly increased toxicity to mysids over this pH range. In contrast, in silversides at 11 g/kg, NH3 toxicity was less at pH 7.0, greater at pH 8, and slightly less at pH 9, relative to the toxicity at 31 g/kg. Temperature had no significant effect on the acute toxicity of un-ionized ammonia with acclimated mysids tested at 18, 25 and 32.5 degrees C, but did have a small effect with acclimated larval sheepshead minnows (Cyprinodon variegatus) tested at 13, 25 and 32.5 degrees C. The chronic toxicity value (the geometric mean of the highest no-effect concentration and lowest effect concentration) at pH 8.0, 25 degrees C and 31 g/kg salinity is 0.061 mg NH3/L for inland silversides and 0.232 mg NH3/L for mysids; the acute:chronic ratio is 21.3 and 7.2, respectively.

Subclinical ammonia toxicity in steers: effects on blood metabolite and regulatory hormone concentrations.

The effects of subclinical NH3 toxicity on circulating and regulatory hormone concentrations were investigated in seven Hereford steers. Ammonium chloride (NH4Cl) was infused via a right jugular vein catheter at a rate of 12 mumol NH4Cl.kg BW-1.min-1 for 240 min. This was preceded (PRE) and followed (POST) by saline infusions of 120 and 180 min, respectively. Blood samples were taken at 20-min intervals via a left jugular vein catheter. Metabolite and hormone concentrations during NH4Cl and POST periods were compared to PRE values using the Student's t-test procedure. Plasma NH3 was elevated rapidly (P less than .001) and peaked at 503 micrograms/dl 220 min into NH4Cl infusion. Plasma urea-N and glucose increased (P less than .001) 39 and 12%, respectively, during NH4Cl infusion and remained elevated 180 min POST. Whole blood L-lactate concentrations peaked (P less than .05) at 18% above PRE between 160 and 240 min into the NH4Cl infusion and gradually returned to PRE values, whereas pyruvate levels were not altered (P greater than .10). Plasma nonesterified fatty acids peaked (P less than .001) at 94% above PRE levels 40 min into NH4Cl infusion, thereafter declining to PRE concentrations. Whole blood acetoacetate and beta-hydroxybutyrate concentrations were not altered (P greater than .10) by NH4Cl administration. Plasma insulin concentration decreased (P less than .05) 26 to 46% during NH4Cl infusion and increased (P less than .05) 89 to 122% during POST. Plasma glucagon levels were not altered by NH4Cl infusion, so molar insulin:glucagon ratio changes resembled those of insulin. Plasma epinephrine, norepinephrine and dopamine did not vary (P greater than .10) with treatment. These results support the hypothesis that the hyperglycemia observed during hyperammonemia may result from an under-utilization of glucose by insulin-sensitive tissues.

Influence of pH and Ammonia Salts on Ammonia Toxicity and Water Balance in Young Channel Catfish

Eight static 24-h median lethal tests were conducted with 16-g channel catfish Ictalurus punctatus at water temperatures of about 21°C. Tests were performed at four acidities with ammonium chloride and with ammonium sulfate. When compared on the basis of un-ionized ammonia nitrogen (NH3-N), ammonium chloride solutions were more toxic than ammonium sulfate solutions. Median lethal concentrations (24-h LC50s) at pH 8.8, 8.0, 7.2, and 6.0 were, respectively, 1.91, 1.45, 1.04, and 0.74 mg NH3-N/L for ammonium chloride, and 2.24, 1.75, 1.16, and 0.81 mg NH3-N/L for ammonium sulfate. Ionized ammonia (NH 4) was not lethal at concentrations up to 1,787 mg NH 4-N/L. Slopes of the probit regressions of NH3-N concentration versus mortality increased with decreases in pH and were nearly vertical at pH 6.0. Hematocrits of channel catfish exposed to lethal ammonia solutions also increased with decreases in pH, indicating an effect on osmoregulation. Plasma osmolality and red blood cell diameters did not change when channel catfish were exposed to NH3-N LC50 solutions at low and high pH; increases in hematocrit were due to isotonic dehydration. Common physiological salts elicited similar blood and lethality responses from channel catfish at pH 6.0 when compared on an equimolar basis to ammonium salt solutions. Hemoconcentration seems to potentiate the toxicity of ammonia by increasing blood ammonia concentrations. If so, isotonic dehydration would account for the apparent increase in the toxicity of NH3 at low pH. Based on acute toxicity tests that account for osmotic effects, NH4 must be considered to be essentially nontoxic to channel catfish.

Distribution of Applied Anhydrous Ammonia in Soils and Germination Hazard to Winter Wheat

AbstractCurrent changes in residue management systems for winter wheat (Triticum aestivum L.) include anhydrous NH3 injection combined with herbicide application, planting, and other field operations. The feasibility of NH3 application during planting is dependent upon potential NH3 toxicity to germinating seeds. A laboratory experiment was conducted to study anhydrous NH3 movement in soils by injecting 124 and 180 mg N as NH3 into a Hollister clay (fine, mixed, thermic Pachic Paleustolls), Grant silt loam (fine‐silty, mixed, thermic Udic Argiustolls), and Norge clay loam (fine‐silty, mixed, thermic Udic Paleustolls) at 0.124 and 0.181 water (kg kg−1) contents. Soil samples were taken 1, 7, and 14 d after N application. Soil NH+4‐N and calculated NH3(aq) concentrations following NH3 injection generated a normal distribution curve with N concentrations highest near the injection point and decreasing with increasing distance. Calculated NH+4 diffusion coefficients decreased with time and water content and were soil dependent. Field studies were conducted in 1983 to determine the potential germination hazard from NH3 applied at 0, 56, 112, 168, 224, and 280 kg N ha−1 while planting, and in 1984 to winter wheat planted 0, 1, 3, 5, 6, and 7 d after applications of 0, 100, and 200 kg N ha−1. Stand counts, forage NO‐3‐N concentration, and yield were not influenced by NH3 applications during planting in 1983, but grain N concentration increased linearly up to 24.1 mg g−1 with 280 kg N ha−1. In the 1984 experiment, increasing NH3 rates did not decrease seedling stand, even though analysis of soil samples reflected increased soil pH and soil NH+4‐N concentration. Anhydrous NH3 placement at a sufficient distance from newly seeded rows will ensure the success of systems which include NH3 injection in conjunction with other field operations in residue management systems.

Ultrastructure of acute ammonia toxicity in the human lung.

A tanker truck carrying anhydrous ammonia (NH3) fell off a freeway, releasing a dense cloud of NH3 gas, killing several people. The driver was dead upon impact. To our knowledge, pulmonary NH3 toxicity in humans has not been studied previously by electron microscopy (EM). Therefore, in two cases, the paraffin-embedded tissue blocks of lung were deparaffinized and reembedded in plastic for 1-mu sections and EM examination. The lung tissue of a third case, the truck driver, was similarly processed as a control. Light-microscopic pulmonary findings in the acute NH3 deaths included denudation of the tracheobronchial epithelium, edema of the lamina propria, and marked alveolar edema, congestion, and hemorrhage. In contrast, in the truck driver's lungs, the bronchial epithelium was intact, and there was no gross odor of NH3. Massive pulmonary hemorrhages in his lungs were attributed to trauma rather than NH3 inhalation. EM examination of the lungs of the truck driver showed no discernible toxic alterations in either the capillary endothelial cells or the Type I or II alveolar epithelial cells, and alveolar and capillary basement membranes were intact. In contrast, EM study of the lungs from two individuals dying acutely of NH3 inhalation showed marked swelling and imbitional edema of Type I alveolar epithelial cells; however, alveolar basement membranes and capillary endothelial cells appeared as usual. These electron-microscopic findings demonstrate the Type I epithelial cell to be the target cell of acute alveolar wall injury in NH3 inhalation.

Fate of Nitrogen‐15‐Labeled Fertilizer Nitrogen in Revegetated Cretaceous Coal Spoils

AbstractWestern wheatgrass (Agropyron smithii L.) was grown in a greenhouse study on two Cretaceous coal spoils and a topsoil to describe the short‐term behavior of several levels of added 15N‐labeled (NH4)2SO4 (0, 60, 120, and 240 mg N kg−1 soil). Recovery and distribution of fertilizer N was measured at harvest in the soil materials and in the harvested tops, roots, crowns, and rhizomes of the western wheatgrass. Fertilizer N uptake by plants grown in the topsoil increased significantly with increasing fertilizer rate, but a significant increase in aboveground biomass did not occur with the 240 mg N kg−1 treatment. In contrast, aboveground biomass on the two spoils increased significantly with the addition of 60 mg N kg−1, but additional increases in plant biomass with higher fertilizer rates did not occur, and a significant decrease in plant biomass occurred with the 240 mg N kg−1 treatment. Significantly lower water holding capacities and cation exchange capacities resulted in significantly higher NH4+ concentrations in solution in the spoil materials as compared with the topsoil. Thus, suppressed seedling emergence and establishment in the spoil materials was attributed to NH3 toxicity and/or phytotoxicity due to NO2− accumulation in the spoil. Substantial fractions of added fertilizer N (65–72%) were immobilized by the plants and into soil organic matter in the topsoil, and only at the highest fertilizer rate did fertilizer N accumulate in mineral form. Under field conditions, this immobilized N should be available for recycling and plant uptake in subsequent years and thus help reestablish a functional N‐cycling ecosystem. In comparison, percent recovery of added N decreased in plant biomass and increased in NO3− form in the two spoils as the rate of fertilizer application increased. Thus, 40 to 50% of added fertilizer N could be susceptible to leaching losses under field conditions.

The Toxicity of Banded Urea or Diammonium Phosphate to Corn as Influenced by Soil Temperature, Moisture, and pH

AbstractA laboratory and greenhouse study, using a Hagerstown silt loam (Typic Hapludalf, fine, mixed, mesic) was designed to determine the effect of initial soil pH, soil temperature, and soil moisture on NH4+ + NH3‐N movement and concentration, pH change, and NO2‐‐N production and accumulation around urea or diammonium phosphate (DAP) banded at 80 or 100 kg N/ha (assuming 76 cm between bands). Observations were also made in the greenhouse on corn root growth around banded urea plus triple superphosphate (TSP), NH4NO3 plus DAP, urea plus DAP, urea plus DAP with 100 kg Mg/ha, and urea plus DAP with a nitrification inhibitor (nitrapyrin). Root growth around those treatments was compared to banded NH4NO3 plus TSP and no‐starter controls. Nitrogen and phosphorus were applied at 100 kg/ha and 60 kg/ha in the band, respectively.Increasing the initial soil pH and decreasing soil moisture increased the proportion of total NH4+ + NH3‐N present as free NH3 around banded urea or DAP. Lowering soil temperature appeared to inhibit nitrification and help maintain high pH and NH4+ + NH3‐N concentrations for a longer time.With both urea and DAP, NH3 toxicity appeared to be the main cause for root growth inhibition around the band. Magnesium did not decrease toxicity symptoms nor did NO2‐ accumulate to toxic levels. Ammonia toxicity potential from DAP was lower than an equivalent amount of urea due to the smaller pH increase adjacent to the band of DAP. At a banded rate of 100 kg N/ha, urea increased the pH in Hagerstown silt loam from 6.8 to 9.1 whereas DAP increased pH to only 7.3.

Concentration of NH3(aq) Required for Incipient NH3 Toxicity to Seedlings

AbstractShort term experiments with sudangrass (Sorghum sudanensis L.) and cotton (Gossypium hirsutum L.) were conducted in a growth chamber to determine incipient toxic levels of NH3(aq). Sudangrass seedlings were grown for 14 days in potted Lucedale sandy loam surface soil treated with different rates of N from NH4OH, (NH4)2SO4, and (NH4)2HPO4. Root growth of cotton seedlings was measured over a 3‐day period in split‐root experiments in which the upper portion of the root medium was a sandy loam surface soil and the lower portion was either a nutrient solution or a treated soil at various levels of pH and ammoniacal‐N. Symptoms of NH3 toxicity were evident on sudangrass foliage at NH3(aq) concentration in the soil solution in situ of 0.17mM and greater; there was no evidence of NH3 toxicity at 0.13mM and less. Symptoms of NH3 toxicity on cotton roots were evident in soil solutions in situ at NH3(aq) concentrations of 0.24mM and greater but not at 0.17mM and less; in nutrient solutions, symptoms were evident at 0.22mM NH3(aq) but not at 0.16mM. The critical concentration for incipient NH3 toxicity was concluded to be 0.15 to 0.20mM NH3(aq).

Calcium Deficiency and Ammonia Toxicity as Separate Causal Factors of (NH4)2HPO4‐Injury to Seedlings

AbstractShort term experiments were conducted in a growth chamber with seedlings of sudangrass (Sorghum sudanensis) and cotton (Gossypium hirsutum L.) on a Lucedale sandy loam surface soil treated with different rates of MgO, CaO, (NH4)2HPO4, K2HPO4, and Ca(H2PO4)2. Sudangrass seed was planted in treated soils and the seedlings were allowed to grow for 14 days, during which time they were observed for symptoms of Ca deficiency or NH3 toxicity. Cotton seed was planted in a layer of untreated soil that was underlain by treated soil in glass‐front boxes for direct observation of root growth. The depth to which each primary root of cotton extended into the treated soil was measured periodically for 3 days after the root entered the treated soil. Results were related to ionic composition of soil solutions in situ. Calcium deficiency symptoms and reduced growth occurred on all soils with aCa/Σacation i ratios in soil solutions of 0.15 or less. Ammonia toxicity symptoms on foliage were caused by only one treatment although toxic concentrations of NH3(aq) were present in three other soil solutions. These solutions were also deficient in Ca. When conditions conducive to Ca deficiency and NH3 toxicity existed in the same soil solution, Ca deficiency symptoms dominated except at the highest NH3(aq) concentration.

Greenhouse Evaluation of the Agronomic Efficiency of Anhydrous Ammonia1

AbstractThree greenhouse pot experiments were conducted with corn grown on Mountview loam and Hartsells fine sandy loam to (a) measure the relative agronomic effectiveness of direct applications of anhydrous NH3, as influenced by preplan incubation period and schedule of application, and (b) to determine the influence of soil moisture content at time of NH3 injection on crop response to anhydrous NH3.Response of corn to anhydrous NH3 tended to be less than to an ammonium N source with shorter incubation periods, but was generally as effective as a nitrate N source except when high N rates were applied at planting. In the latter case, yields were somewhat reduced.When anhydrous NH3 was injected into the soil‐root zone according to different application schedules, corn yields were considerably reduced at the higher N levels when compared to equivalent applications of urea and NH4NO3. Yield reduction in these cases was attributed in part to root damage due to NH3 toxicity, and possibly to temporary positional unavailability of the applied N. Soil‐cultured corn plants, however, appeared to be remarkably tolerant to high levels of anhydrous NH3 when applied directly into the root zone.A small but consistent decrease in yield was observed when high levels of anhydrous NH3 were applied to soils in an air‐dry rather than moist condition.

Die Temperaturabhängigkeit der Giftwirkung von Ammoniak auf Fische: III. Mittlg. der Reihe: Beiträge zur Toxikologie der Fische

Summary1. The toxicity of NH3 on adult Squalius under different temperature conditions has been investigated.2. For such experiments the increasing dissociation of ammonia with increasing temperatu...