Saltwater exposure

Resistance of the adhesive joint to salt climates depends not only on the type of adhesive but also on the method of surface preparation and on the type of primer used. The good bond durability in saltwater exposure of anodized surface pretreated joints has been shown... 

Anodizing pretreatments on aluminum should be ranked as phosphoric acid chromic acid > sulfuric acid with regards to their bond durability under simultaneous stressing and corrosive, saltwater exposure conditions. 

Most etching, anodizing, or conversion coating surface preparation will produce joints of superior durability under stress and corrosive, saltwater exposure conditions. Mill-finish, vapor-degreased, or mechanically abraded surface joints performed poorly in comparison, regardless of alloy choice. 

J.D. Minford, "Effect of Surface Preparations on Stressed Aluminum Joints in Corrosive Saltwater Exposure," Adhesives Age, 2, No. 10, 36 (1980). 

Magnesium alloys have a reputation for poor corrosion performance, particularly in saltwater exposures. In large part, this is due to a lack of control, historically, of the... 

J. D. Minford, Comparative aluminum joint evaluations in varying saltwater exposure conditions, J. Adhes. 18, 19 (1985). 

Dietary source required if insufficient exposure to UV light. Vitamin 1% is found in saltwater fish (salmon) and egg yolks. 

To protect aquatic organisms from arsenic and other contaminants, the US state of California has established criteria maximum concentrations (CMC) and criteria continuous concentrations (CCC) for most inland surface waters, bays, and estuaries (40 CFR 131.38). The CMC is the highest concentration of a contaminant in a surface water that will not show any deleterious effects to aquatic life after exposure for a brief period of time (an average of 1 hour) (40 CFR 131.38, 131.36). The CCC is the highest concentration of a contaminant that aquatic life will not show any deleterious effects after exposure for four days (an extended period of time ) (40 CFR 131.38). For freshwater, the dissolved arsenic CMC is 340 pg r1. The CMC for saltwater is 69 pg I1. The dissolved arsenic CCCs for freshwater and saltwater are 150 and 36 pgl-1, respectively (40 CFR 131.38). 

Freshwater fish tests are generally conducted on bluegill, a warm water fish, and rainbow trout, a cold water fish. Catfish, fathead minnows and sometimes carp are also used depending on the expected route of exposure. Sheepshead minnow is the commonly used saltwater fish. 

Four types of exposure conditions are employed in both acute and chronic tests and in both freshwater and saltwater media static, static-renewal (semi-static), recirculation, and flow-through. The choice for which test type to use usually depends on test substance characteristics, test duration, test species, and regulatoiy requirements. 

The US Environmental Protection Agency ECOTOX database has very few records for decane. An acute (48-96 h) no-observed-effect concentration of 500 mgl was recorded for the sheepshead minnow (saltwater fish). Acute effects (48 h exposure) on the water flea (Daphnia magna LC50) ranged from 1.3 to 29mgl (freshwater cladocercan). 

Due to concerns over potential exposure of aquatic organisms to NP, a number of acute and chronic toxicity tests have been conducted for both freshwater and saltwater species of invertebrates, fish, and aquatic plants. NP is considered an endocrine dis-ruptor chemical and induces production of vitellogenin in male rainbow trout, a process that normally occurs only in female fish in response to estrogenic hormones during the reproductive cycle. NP also induces precocious development of ovaries and an intersex condition in some fish species. 

Hair. Scalp hair is another primary indicator used to assess methylmercury exposure, because the methylmercury is incorporated into the hair at the hair follicle in proportion to its content in the blood (EPA 1996d). The typical hair-to-blood ratio in humans has been estimated to be about 250 1 expressed as g Hg/g hair to mg Hg/L blood, but some difficulties in measurements, inter-individual variation in body burden, differences in hair growth rates, and variations in fresh and saltwater fish intake have led to varying estimates (Birke et al. 1972 Skerfving 1974). Once incorporated into the hair strand, the methylmercury is stable and gives a longitudinal history of blood methylmercury levels (WHO 1990). 

EXPOSURE ROUTES drinking water raw wastewater from textile plants wastewater from 2,4,6-trinitotoluene production saltwater... 

The saltwater aquatic life protection criterion of 4.5 tLg Cd/L seems adequate to prevent death, but will not prevent potentially deleterious physiological effects, including dismpted respiration in crustaceans and teleosts. Incidentally, at 5.0 ttg Cd/L, the lowest concentration critically examined, oysters biomagnify ambient levels to concentrations hazardous to human consumers and possibly other animal consumers. The maximum allowable concentration (MAC) in saltwater during a 24-h period was recommended as 59.0p,g/L (Table 5.2). However, death of various species of marine crustaceans was reported at 60.0 p,g Cd/L after exposure for 6 weeks and at 14.8-19.5 ttg/L after 23-27 days. Furthermore, a MAC of... 

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