Cumulative Toxicity

Acute toxicity Cumulative toxicity Absorption from various routes... 

Load, Pb a highly toxic cumulative element in man and animals It affects adversely nearly all steps in heme syntheds it inhibits the mitochondrial enzyme... 

Health and Safety Factors. VDE is a flammable gas its combustion products are toxic. Liquid VDE on contact with the skin can cause frostbite. Acute inhalation toxicity of VDE is low median lethal concentrations (LC q) for rats were 128,000 ppm after a single 4-h exposure (52) and 800,000 ppm after a 30-min exposure (53). Cumulative toxicity is low exposure of rats and mice at levels of up to 50,000 ppm for 90 days did not cause any... 

Health and Safety Factors. MEK is slightly more toxic than acetone, but is not considered highly toxic, and nor does it exhibit cumulative toxicological properties. The OSHA time weighted average iu air is 200 ppm other measured toxicity values are shown iu Table 3. Methyl ethyl ketone is highly flammable. 

Toxic Substances ControlA.ct Chemical Substances Inventory Vol. 3, U.S. Environmental Protection Agency, Washington, D.C., May 1979, Cumulative Suppl., July 1980. 

Cumulative effects are those where there is progressive injury and worsening of the toxic effect as a result of repeated-exposure conditions. Each exposure produces a further increment of injury a dding to that already existing. Many materials known to induce a particular type of toxic effect by acute exposure can also eUcit the same effect by a cumulative procedure from repetitive exposure to a dose less than that causing threshold injury by acute exposure. 

It is important to appreciate that the magnitude of the absorbed dose, the relative amounts of bio transformation product, and the distribution and elimination of metaboUtes and parent compound seen with a single exposure, may be modified by repeated exposures. For example, repeated exposure may enhance mechanisms responsible for biotransformation of the absorbed material, and thus modify the relative proportions of the metaboUtes and parent molecule, and thus the retention pattern of these materials. Clearly, this could influence the likelihood for target organ toxicity. Additionally, and particularly when there is a slow excretion rate, repeated exposures may increase the possibiUty for progressive loading of tissues and body fluids, and hence the potential for cumulative toxicity. 

Cumulative organ toxicity also presents a significant obstacle for effective chemotherapy. In many cases, the severity of the toxicity impedes the broader use of an agent. Other specific toxicities are associated with specific agents, for example cardiotoxicity with adriamycin (32), renal toxicity with i7j -platinum (28), and neurotoxicity with vincristine (49). 

Cationic flocculants are widely used in clearing oil-water, waste, natural and drinking water. At the sarue time they ar e moderately toxic substances which have cumulative properties. For the majority of flocculants, prodused and used in Ukraine, limit admission concentration is 0,l-t-0,4 mg/dm for drinking water and 0,01 mg/dm and less - for natural waters. 

Acute daphnia toxicity Biodegradability Physico-chemical properties cumulative... 

BASE SET Mutagenicity Toxicity to reproduction Toxicity to algae Acute daphnia and fish toxicity Abiotic and readily biotic degradability Additional physico-chemical properties 1 t/annum or 5 t cumulative... 

Upper LEVEL 1 Chronic toxicity Toxicity in soil and plants Additional mutagenicity Long-term toxicity Bioaccumulation Inherent biodegradability Additional abiotic degradability 100 t/annum or 500 t cumulative... 

Additional chronic toxicity Additional environmentally dangerous properties Toxicity to birds Long-term toxicity in water and soil Degradability simulation tests Additional abiotic degradability Mobility in water, soil and air cumulative... 

Toxicity. MEDINA is apparently non-toxic to rabbit penile mucosa its cumulative effect on abraded and intact rabbit skin is slightly greater than Tetryl no damage was observed to rabbit cornea and there was no evidence of sensitization by subcutaneous injection in guinea pigs. It was concluded that its toxicity is similar to that of Tetryl (Ref 11, p 138)... 

Methanol is a dangerous fire hazard when exposed to heat or flame, and a moderate expl hazard when exposed to flame. It is a dangerous disaster hazard upon exposure to heat or flame, and can react vigorously with oxidizing materials. Methanol possesses distinct narcotic props, and is also a slight irritant to the mucous membranes. Its main toxic effect is exerted upon the nervous system, particularly the optic nerves and possibly the retinae. In the body the products formed by its oxidn are formaldehyde and formic acid, both of which are toxic. Because of the slowness with which it is eliminated, methanol should be regarded as a cumulative poison (Ref 5)... 

Fhtients with liver or kidney disease are usually given dragp with caution because a cumulative effect may occur. When the patient is unable to excrete the drug at a normal rate the drug accumulates in the body, causing atoxic reaction. Sometimes, the primary health care provider lowers the dose of the drug to prevent a toxic drug reaction. 

In summary, neurotoxic effects of endosulfan are usually apparent only after acute ingestion of relatively high doses. Cumulative neurotoxicity does not appear to be significant. If the animal survives the acute toxic effects, then no long-term neurotoxic effects are evident from behavioral, gross, and microscopic observations. However, some impairment may occur that can be detected only by specialized neurobehavioral testing. 

Gupta PK, Murthy RC, Chandra SV. 1981. Toxicity of endosulfan and manganese chloride Cumulative toxicity rating. Toxicol Lett 7 221-227. 

Hoechst. 1989b. Endosulfan-beta - substance technical (code HOE 052619 OI ZC99 0001) Preliminary cumulative dermal toxicity (5 treatments on 5 successive days) in the Wistar rat. Hoechst Aktiengesellschaft, Erankfurt, Germany. Report no. 89.0891. [unpubhshed study]... 

In summary, there is as yet no clear evidence that superwarfarins have caused any widespread declines of predators and scavengers that feed on rodents. However, the persistence and very high cumulative toxicity of these compounds suggest that they could pose a serious hazard to such species if they were to be more widely used. The situation needs to be kept under close review. 

REDUCED Additional acute toxicity Acute daphnia toxicity Biodegradability Physico-chemical properties 100 kg/annum or 500 kg cumulative... 

---