Adverse effects of (surface water pollutants) Cd, Cr and Pb on the embryogenesis of the mallard.

The effects of chromium, lead and cadmium were studied on the embryogenesis, hatching success and viability of the mallard. Eggs were exposed to relatively low environmental concentrations that are characteristic to the level in polluted Hungarian surface waters. Eggs were treated by injection or immersion--prior to incubation. In study I, effects on early embryogenesis (first 10 days of incubation) were examined. Eggs were opened daily, mortality was determined and permanent slides of the embryos were made to help further external examinations. Each metal proved to be toxic to the developing mallard embryo, causing an increase in mortality and developmental anomalies. Chromium was the most teratogenic of the three heavy metals increasing the rate of malformations by 30% (P<0.001) after immersion, and 17% (P<0.01) after injection of the eggs. Cadmium proved to cause the highest rate of mortality. Embryonic death was increased by 27% (P<0.01) and 40% (P<0.001) after Cd immersion and injection, respectively. In study II, effects on hatching and viability of the ducklings were studied. The eggs were hatched, hatching and mortality rates were established, the liver of animals was histopathologically examined. However each heavy metal decreased hatching success, cadmium was found the most toxic compound, causing a 21% (P<0.01) and 47% (P<0.001) reduction in hatching success after immersion and injection, respectively. The liver of hatched ducklings showed significant lesions, dystrophy in the form of hepatic necrosis was detected in each treated animal. Each heavy metal (Cr, Pb, Cd) proved to have adverse effects on the embryonic development, hatching and viability of the mallard.

Toxicity and degradation of metolachlor (Dual Gold 960 EC) in chicken embryos.

The herbicide formulation Dual Gold 960 EC (960 g/l metolachlor) was applied, ROSS 308 embryonated hen eggs were treated on day 12 of incubation period. The pesticide was diluted in water to a concentration level 0.3% and the emulsion was injected into the air space in a volume of 0.1 ml/egg, or hen's eggs were treated by the immersion technique (30 min). Residues of metolachlor were measured by GC in 14 collected embryo samples on days 13, 15 and 19 of the incubation of chicken embryos, and macro- and microscopic morphological examinations of 49 embryos were performed simultaneously on day 19. Body mass of embryos was weighed on 13th, 15th and 19th day of incubation. After the both treatments the mortality rate of embryos was similar. The average data of body mass showed a significant decrease compared to the control in the immersion study on day 15 and 19 of the hatching period. This phenomenon may only be in connection with the presence of metolachlor over the limit of quantification (LOQ) on day 13 of incubation period. The macroscopic deformations were sporadic in the embryos. No histologically detected alterations were seen.

Toxicity of a mancozeb containing fungicide formulation and CU-sulphate to chicken embryos after administration as single compounds or in combination.

Environmental pollution of metal modelled by copper-sulphate and a 80% mancozeb containing fungicide formulation (Dithane M-45) were studied on chicken embryos after administration as a single compounds or in combination. The test materials were injected into the air-chamber in a volume of 0.1 ml/egg on day 12 of incubation. The concentration of copper-sulphate was 0.01%. The applied concentration of Dithane M-45 fungicide formulation was 0.2%. Evaluation was done on day 19 of the hatching period. The combined administration of copper-sulphate and the fungicide formulation did not cause a significant reduction in body weight as compared to the control data and the results from individual toxicity study of the test materials. After the combined administration of copper-sulphate and the fungicide formulation the rate of embryomortality was 40%. The incidence of developmental anomalies were sporadic. Light microscopic findings exhibited a degenerative change in the liver tissue of combined administration group. Activities of GPT and GOT enzymes increased markedly in the combined administration group. In summary, it can be established that the interaction of copper-sulphate and an 80% mancozeb containing fungicide formulation (Dithane M-45) caused higher embryomortality with respect to the test of individual toxicity of copper-sulphate and fungicide in our study.

Toxicity and degradation of benefin in chicken embryos.

The herbicide formulation Flubalex (20% benefin) was applied, ROSS 308 embryonated hen eggs were treated on day 12 of incubation period. The pesticide was diluted in water to a concentration level of 3.0%, and the emulsion was injected into the air space in a volume of 0.1 ml/egg, or hen's eggs were treated by the immersion technique. Residues of benefin were measured in the samples on days 13, 15 and 19 of the incubation of chicken embryos, and morphological examinations were performed simultaneously. After the immersion treatment the mortality rate of embryos was remarkable compared to the injection treatment. Analytical chemistry data showed the concentration of the active ingredient which was 3.5 times higher on day 13 of incubation in the samples after immersion treatment than after the injection of benefin. This resulted an increased incidence rate of mortality. On day 19 of hatching period the benefin concentration was practically similar independently of treatment method. No macro- and microscopic alterations were seen.

Teratogenicity testing of BI 58 EC (38% dimethoate) in chicken embryos with special respect to degradation of the active ingredient.

The insecticide formulation BI 58 EC was tested for teratogenicity in chicken embryos, with particular reference to degradation of the active ingredient (dimethoate) after the treatment of embryonated eggs. The pesticide was diluted in water to a concentration level of 0.8%, and the emulsion was injected into the air space in a volume of 0.1 ml/egg, or hen's eggs were treated by the immersion technique. Residues of dimethoate were measured in the samples on days, 13, 15 and 19 of the incubation of chicken embryos, and morphological examinations were performed simultaneously. Analytical chemistry data indicated a slower degradation of dimethoate in embryos after the immersion of eggs, and cyllosis was remarkable in this group among the sporadic developmental anomalies. The liver tissues of both treated groups exhibited severe fatty infiltration.

Teratogenicity testing of dimethoate containing insecticide formulation (BI 58 EC) in chicken embryos.

BI 58 EC insecticide formulation was tested for teratogenicity in chicken embryos after the treatment of embryonated eggs. The pesticide was diluted in water to 0.8% concentration level, and the emulsion was injected into air space in a volume of 0.1 ml/egg or hen eggs were treated by the immersion technique. The morphological examinations were done on the days 13, 15 and 19 of incubation of chicken embryos. BI 58 EC produced an increased embryo mortality after the treatment which was the most expressive on day 15 of incubation. The trend of embryo weight showed similarity in the control and treated groups after both treatments. The developmental anomalies were sporadic and dose-effect dependency was not seen. Light microscopic findings exhibited a degenerative change in the liver tissue of both treated groups. In summary, the 38% dimethoate containing pesticide formulation (BI 58 EC) was toxic to the developing embryo at 0.8% concentration in our study.

Histological examination of CAM treated with irritative pesticides.

The potential irritancy of compounds may be detected by observing adverse changes which occur in the chorioallantoic membrane (CAM) of the egg after exposure to tested chemicals. In our experiment irritating pesticides (Fusilade S, Karathene LC) and a technical component of pesticide (Trend) are tested and their effects are examined on tissue structure of CAM. After 10-11 days of incubation of chicken embryos the chorioallantoic membrane becomes trilaminar. The outer layer is chorionic epithelium between the two rows of cuboidal cells, thin-walled vascular sinuses can be found. In the intermediate layer, the mesenchyme, well-developed blood vessels can be seen. The inner layer is formed by allantoic epithelium. After the treatment with Fusilade S the wall of the blood vessels was damaged, and blood diffused from the blood vessels. After the treatment with Karathane LC rupture of the wall of the blood vessels could be seen and blood appeared around the blood vessels. Blood vessels of the yolk sac were frequently damaged under CAM.

Teratological examination of the insecticide methylparathion (Wofatox 50 EC) on pheasant embryos. 1. Morphological study.

Teratogenic effects of methylparathion / Wofatox 50 EC/ and Parathion 20 WP as positive control material were tested in pheasant embryos. On the 12th day of incubation 0.1 ml of the emulsions or suspensions of the insecticides at different concentrations was inoculated into the air space of embryonated eggs. The following dose levels were employed: 27 and 270 mg/kg egg of Wofatox 50 EC, and 10 mg/kg of Parathion 20 WP. Morphological changes were evaluated by macroscopic, skeletal staining and light microscopic examinations of the embryos. Primary hypoplasia or atrophy developed in the cervical musculature /m. longus colli/ accompanied by lordosis and scoliosis of the cervical spine. In most cases we also found cyllosis .