S. Muramoto

Vertebral column damage and decrease of calcium concentration in fish exposed experimentally to cadmium

Abstract The variations of the Ca, P, Mg and Cd concentrations in the bodies of deformed and normal fish exposed for long periods to water containing low chemical concentrations of Cd were determined. The vertebrae of the fish were then examined by X-ray photography and the mechanism of the development of malformation caused by the loss of Ca from the bones was studied. Deformed fish appeared on the 47th, 85th and 73rd days after Cd exposure in water containing 0·01, 0·05 and 0·1 ppm of Cd, respectively. Due to exposure to the Cd-containing water, the Cd content of the fish increased, whereas the Ca and P contents in the vertebrae tended to decrease. Cavitation of the bone metabolism and contracted adhesion of articulations and strain at the costal apices due to pressure were observed. The percentage of ash weight/dry weight in the bones was also reduced in the deformed fish.

Elimination of copper from Cu‐contaminated fish by long‐term exposure to EDTA and fresh water

Abstract The changes of the Cu and Cd concentrations in the bodies of the Cu‐contaminated fish exposed for long periods to fresh water and EDTA were determined. The fish exposed to Cu‐containing water for 90 days (Cu‐contaminated fish) had 3.2, 2.7 and 1.7 times the Cu content for viscera, gills and other parts in the 0.01 ppm Cu group compared with fish at the beginning of the experiment, and had 11.3, 3.3 and 2.5 times for viscera, gills and other parts in the 0.05 ppm Cu group, respectively. The fresh water and EDTA treatment for 90 days in removing heavy metals from Cu‐contaminated fish tended to reduce the levels of Cu in the fish as the almost equal to those of the fish at the beginning of experiment. After the fish had been kept for 90 days in Cu‐containing water, the Cd content had also increased in the three parts of fish. Treatment with complexan or fresh water after the accumulation of Cd had an effect on the decrease of Cd content in the bodies of the Cu‐contaminated fish.

The critical levels and the maximum metal uptake for wheat and rice plants when applying metal oxides to soil

Wheat is more sensitive to CdO and ZnO compared with rice plant. The yield of wheat decreased by 30% in the presence of 30 ppm Cd, but that of rice plants by only 8%. The critical levels of meal uptake by wheat and rice plants for applying metal oxides to soil (CdO, ZnO, PbO) were determined. The highest concentration obtained for wheat grain was 141 micrograms/g Cd at the Cd 10,000 ppm in soil. This value is higher than the value of 4.97 micrograms/g for unpolished rice and higher than any other we have seen in the reports for treatment with CdO. Also, concentration of more than 1.0 micrograms/g Cd in wheat was observed at 5 pm Cd, while similar concentrations for rice plants were observed at 30 ppm Cd in soil.

Effect of salinity on the concentration of some elements in water hyacinth (Eichhornia crassipes) at critical levels

Abstract The lethal level of salinity for water hyacinth was about 6.0 ‐ 8.0 % (about 20–25 % of sea water). Some element contents of water hyacinth (Eichhornia crassipes) decreased with increasing salinity in culture water. Especially the contents of P, Si, Fe, Al, Mn, Mo in both tops and roots, Ca.Cu.Ti.V in roots, and Ba in tops changed at relatively low salinity levels. On the other hand, the contents of Ba, Sr, V in tops, and Ca, Si, Ti in roots increased with increasing salinity in water. It is assumed that the metal concentration of water hyacinth changes quickly after exposure to salinity for relatively short time.

Variation in some element contents of water hyacinth due to cadmium or nickel treatment with or without anionic surface active agents

Abstract The changes in some metal components of water hyacinth by exposure to cadmium, nickel with or without surface‐active agents are determined. Metal contents of Cd, Ni, Al, Ca, Si, Mn in tops and roots were changed in relatively short time by treatment with Cd or Ni. The values of concentration factors are reduced in both tops and roots under the presence of the anionic surface‐active agents.

Effects of surface‐active agents on the salinity tolerance of water hyacinth (Eichhornia crassipes)

Abstract Recently, water hyacinth (Eichhornia crassipes) (Mart.) solms) has received attention because of its potential for removal of pollutants when utilized as a biological fitlation system. The inffluential levels of salinity and surface‐active agents in water for the growth of its plants were determined. The lethal level of salinity for water hyacinth is between about 6.0 ‐ 8.0 % of sea water, and is slightly higher than those 2.3 %, reported several years ago.

Reductions of Cd in a Cd‐contaminated fish by long‐term exposure to EDTA or fresh‐water

The variations in Cd levels with the passage of time in the viscera and gills of carp (Cyprinus carpio L.) after exposure to 0.01 and 0.05 ppm Cd containing water for 3 months were determined. After 3 months, the fish were treated with fresh-water. The fresh-water treatment produced slow recovery in the viscera, but the Cd concentration in the gills remained approximately the same. From the results of the study, it was postulated that the recovery of fish contaminated with Cd and other heavy metals would seem possible due to loose bindings of the metals to protein of the fish. (JMT)

Distribution and fate of surface active agents in river and lake water, affected by domestic and agricultural wastewater, in an area in Japan

Abstract We investigated the conditions surrounding the outbreak for anionic surface active‐agents in water at river, lake and seaside. The anionic surface active‐agents found in sewage usually come from detergents and chemicals. The daily changes in the concentration of surfactants in river water were affected by the wastewater from residential areas corresponding with washing times at morning, lunch, and dinner on December 29–30,1993. The range of concentrations of anionic surfactants in river water was 74–355 μg/L, average 180 μg/L in May; 74–472 μg/L, average 153μg/L in July; 79–383 μg/L, average 152 μg/L in September; 71–394 μg/L, average195 μg/L in December in 1993. The reduction of the concentration of the anionic surfactants with downstream flow was to dilution with irrigation water but also to biodegradation.

Effects of fertilizers on the vicissitude of cadmium in rice plant

Abstract Some phosphatic fertilizer and phosphorite contained high concentration of cadmium, 4–77 μg/g Cd and were considered one of the causes increasing the cadmium content in rice plants. Unlike, the manure heap, the human excrements contained low cadmium, 0.003–0.03 μg/g Cd, but the Cd content in human excrements in Cd‐polluted areas ranged from 20.1 μg/g Cd to 85.0 μg/g, Cd in ash. The cadmium content of rice produced using prevailing methods of fertilizer culture, since around 1910, tended to be slightly higher than those during the Meiji periods, 1800s. After 1920, these values increased higer compared with those of before the beginning of import of phosphorite in Japan.

Influence of complexans (NTA, EDTA) on the toxicity of nickel chloride and sulfate to fish at high concentrations

Abstract The effect of complexans(NTA,EDTA) on the toxicity of nickel chloride and sulfate to carp (Cyprinus carpio L.) , and on the accumulation of metals in fish at lethal level concentrations was studied. The toxicity of nickel salts to carp was relatively lower, and nickel chloride was more toxic than nickel sulfate. The concentration of metals in fish exposed to nickel chloride and sulfate was remarkably lower than those in the fish exposed to another some heavy metals, such as Cd, Pb, Zn, Cr and Al which were reported in the previous papers. The inhibition of metal accumulation by the presence of complexans was recognized in each part of the fish, but no significantly decrease of mortality of fish to the toxicity of nickel salts.