Mean levels

The solvent has a sweetish odour similar to chloroform detectable at about 30 ppm. It is primarily a depressant of tlie central nervous system (CNS). Significant impairment of performance in behavioural tests and some CNS effects have occuiTed at 1000 ppm but not at 300 ppm prenarcotic symptoms have occuired at mean levels of 200 ppm to 300 ppm. 

Exposure to sulfur dioxide in the ambient air has been associated with reduced lung function, increased incidence of respiratory symptoms and diseases, irritation of the eyes, nose, and throat, and premature mortality. Children, the elderly, and those already suffering from respiratory ailments, such as asthmatics, are especially at risk. Health impacts appear to be linked especially to brief exposures to ambient concentrations above 1,000 ixg/in (acute exposures measured over 10 minutes). Some epidemiologic studies, however, have shown an association between relatively low annual mean levels and excess mortality. It is not clear whether long-... 

Figure 3 presents the mean levels of self-infusion for the 14 phenylethyl-amines shown in figure 1. Of all the drugs tested, injection rates were... 

The version 1.0 bDNA assay was compared with the Monitor and NASB A HIV-1 RNA assays in three clinical evaluations (Coste et al., 1996 Revets et al., 1996 Schuurman et al., 1996). Coste et al. (1996) found that the sensitivity of the bDNA assay was lower (68.3%) than that of both the Monitor (93.3%) and NASBA (100%) assays for detection of HTV-1 RNA among 60 plasma specimens. When results with specimens for which the RNA levels were higher than the lower quantitation limit of each method were analyzed, the mean levels by Monitor, bDNA, and NASBA were 5.38 0.52,5.03 0.55, and 5.39 0.53 log10 copies/ml, re-... 

Fig. 8. Variation with location of the mean levels of "Tc in samples of Fucus serrantus bioindicators along the French coast of the English Channel. The discharge outlet at the La Hague reprocessing plant is shown by an arrow. (Reprinted with permission from Ref. 43. Copyright (1987) Elsevier Science Ltd)...

The next column reports the mean residue level found in conventional samples and the last column shows the ratio of the residue level in the organic sample compared to the mean of the residues in conventional samples. Residues in this table are ranked in descending order relative to this last column. Any value over about 0.5 in this last column suggests mislabeling, since the residue level in the organic sample was no less than one-half the mean level in all-positive conventional samples. Half to two-thirds of the residues in Table 14.5 are likely reflect mislabeling, while perhaps one-third are likely to be cases of inadvertent drift or cross-contamination. 

Results may confirm the need for novel policy interventions to more fairly divide the risk reduction burden between US farmers and those growing crops for export to the USA. Recent trends in methamidophos residues in a variety of Mexican produce imported into the USA are particularly worrying, especially in contrast to the solid progress made by US growers in reducing the frequency and mean levels of methamidophos residues in the same foods. 

EPA research investments since 1995 in pesticide exposure and risk assessment methods have helped pioneer novel approaches to quantify risk levels. A team at the University of Washington s School of Public Health and Community Medicine found that 2-5 year olds consuming predominantly organic foods over a 3-day period had 8.5-fold lower mean levels of OP insecticide metabolites in their urine than children eating mosdy conventional (unlabeled) foods (Curl et al., 2003). The study was carefully designed to minimize potentially... 

Compared to adults, the daily intake of PCDD/PCDFs and PCBs by breastfed babies is 1-2 orders of magnitude higher. A recent field study showed higher mean levels of PCDD/PCDFs and PCBs in human milk in industrialized areas (10-35 pg I-TEQ/g milk fat) and lower levels in developing countries (< 10 pg I-TEQ/g milk fat). Very few studies have been performed on Arctic populations with respect to the exposure of children to these substances. It is likely, however, that the differences in exposure between children and adults demonstrated in many industrialized regions also exist in Arctic regions. 

Ritcey, J. A. Censored mean-level detector analysis, IEEE Transactions on Aerospace and Electronic Systems, AES-22, 3 (July 1986), pp. 443-454, 1986. 

Mirex levels in the blood of pregnant women in Jackson, Mississippi, and the Mississippi Delta area where mirex was extensively used were correlated with the health of the infants they bore. The mean mirex level in maternal blood was 0.54 pg/L (ppb) for 106 samples however, mirex levels in the blood of the infants were not correlated with differences in gestation times, Apgar score, or other problems at birth. Only three children with neurological problems had mothers with pesticide levels, including mirex, above the mean levels (Lloyd et al. 1974). 

Population subsamples of American and African blacks, however, show a significantly different bell-shaped Lp(a) distribution (H6, P5, S40) (Fig. 7). The mean levels are twice those in Caucasians, indicating that the Lp(a) distribution depends upon race (G37). As there is an inverse relation between apo(a) size and plasma concentration, the distribution of different genotypes and allele frequencies is also dependent upon race (C6, Ml3). 

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