Chronic toxic effects

The toxicity of these fluoroaluminates is mainly as inorganic fluorides. The ACGIH adopted (1992—1993) values for fluorides as F is TLV 2.5 mg/m. The oral toxicity in laboratory animal tests is reported to be LD q rat 2.15 mg/kg (41). Because of the fine nature of the products they can also be sources of chronic toxicity effects as dusts. 

In additional EPA studies, subchronic inhalation was evaluated ia the rat for 4 and 13 weeks, respectively, and no adverse effects other than nasal irritation were noted. In the above-mentioned NTP chronic toxicity study ia mice, no chronic toxic effects other than those resulting from bronchial irritation were noted. There was no treatment-related increase ia tumors ia male mice, but female mice had a slight increase in bronchial tumors. Neither species had an increase in cancer. Naphthalene showed no biological activity in other chemical carcinogen tests, indicating Htde cancer risk (44). No incidents of chronic effects have been reported as a result of industrial exposure to naphthalene (28,41). 

Vanadium compounds, including those which may be involved in the production, processing, and use of vanadium and vanadium alloys, are irritants chiefly to the conjuctivae and respiratory tract. Prolonged exposure may lead to pulmonary compHcations. However, responses are acute, never chronic. Toxic effects vary with the vanadium compound involved. For example, LD q (oral) of vanadium pentoxide dust in rats is 23 mg/kg of body weight (24). 

Sastry, K.V. and K. Sunita. 1984. Chronic toxic effects of chromium in Channa punctatus. Jour. Environ. Biol. 5 47-52. 

Thus the total soil pollution was connected with a respiratory system and a digestive tract. Both systems were also sensitive to such urban pollutants as heavy metals and PAH. For radionuclides the correlation with the given nosologies was not revealed. The asthma morbidity was mostly connected with soil pollution rates. This circumstance, apparently, can be related to nonspecific action of pollutants on a human organism, because the etiology of asthma is connected with the human immune defense system and allergy state (Roite, 1991). The last was shown for pesticides (Nikolaev et al., 1988) and heavy metals (Drouet et al., 1990). The sensitized immune system is, apparently, responsible for chronic toxic effects of other pollutants at low doses (Sidorenko et al., 1991 Novak and Magnussen, 1993). 

Absence of carcinogenity, genotoxicity, developmental and reproductive toxicity and of chronic toxicity effects at low exposure levels are indispensable prerequisites for food additive approvals. All substances approved in the European Union or the USA or deemed generally recognised as safe (GRAS) in the USA fulfil this requirement. 

For instance, an extrapolated water TBT concentration (0.21 5.9 ngL-1) based on concentrations of TBT and its bioconcentration factors (5000 10,400 for TBT in mussel and 9400-11,000 in marine fish) (Sudaryanto et al., 2005d) were also close to or above the threshold levels of toxic implications, such as imposex in mollusks and immunotoxicity in mussel (St-Jean et al., 2002). The levels were also near to the criteria established by US-EPA (2003) to protect saltwater aquatic life from chronic toxic effects of TBT (0.0074 pg L-1). Indeed, high incidence of imposex in gastropods has been shown to occur in Indonesia, such as the Ambon coastal area (Ellis and Pattisina, 1990). An evidence of ecotox-icological impact of TBT, imposex incidence is also a usual phenomenon in gastropods in coastal waters of some other Asian countries... 

Inherent potential or capacity of a material to cause chronic effects that occur following long exposure times. For S. capricornutum, whose cell numbers double every 12 h at 24° C, a 3-d contact time with a test sample corresponds to a chronic exposure period allowing for the determination of corresponding chronic toxicity effects. See also Chronic effects and Chronic exposure. Volume 1(3,5), Volume 2(2,5,11). 

Because of their widespread use and disposal in the environment, the toxicities of the alkenyl halides are of considerable concern. They exhibit a wide range of acute and chronic toxic effects. 

Arsenic is a by-product of the smelting of copper, lead, and zinc ores. It has been shown to produce acute and chronic toxic effects, with the trivalent (3+) form as the most toxic. Arsenic has been classified in the EPA s Group A (human carcinogen), and it is regulated by the U.S. government. 

Methoxychlor, a chemical closely related to DDT, has been used as an insecticide. The half-life for methoxychlor in water is rather short (46 days) and it is not considered to be persistent. Methoxychlor has been classified in the EPA s Group D (not classifiable). At high doses, methoxychlor has been shown to exhibit chronic toxic effects and has been detected in drinking water. 

In the prediction of long-term "no effect" doses there are two important concepts to consider. One is that there are predictable dose relationships between acute, subchronic and chronic toxic effects. Acute toxicity tests refers to studies wherein single or repeated doses are studied 14 days or less. Subchronic (subacute) tests refers to studies wherein the doses are given five-seven days per week for 90 days, Subchronlc studies are also referred to as 13-week, three-month or short-term tests. 

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