An environmental measurement and correlation study of nondietary ingestion of pesticides was carried out in a colonia in south Texas. The purpose of the study was to evaluate young children's exposure to environmental levels of organophosphate ( OP ) pesticides in the household. Samples were collected to measure levels of OP pesticides in housedust and on children's hands. These, in turn, were compared to levels of OP pesticide metabolites in urine. A total of 52 children, 25 boys and 27 girls, participated in the spring and summer of 2000. The children were 7 -53 months of age at the time of recruitment. Univariate and multivariate regression analyses were carried out using SAS statistical software. Seventy -six percent of housedust samples and 50% of hand rinse samples contained OP pesticides. All urine samples had at least one metabolite and over 95% had at least two metabolites above the limit of detection ( LOD ). Total OP loadings in the housedust ranged from nondetectable ( nd ) to 78.03 nmol / 100 cm 2 ( mean = 0.15 nmol / 100 cm 2 ; median = 0.07 nmol / 100 cm 2 ); total OP loadings on the children's hands ranged from nd to 13.40 nmol / 100 cm 2 ( mean = 1.21 nmol / 100 cm 2 ; median = 1.41 nmol / 100 cm 2 ), and creatinine corrected urinary levels ( nmol / mol creatinine ) of total OP metabolites ranged from 3.2 to 257 nmol / mol creatinine ( mean = 42.6; median 27.4 nmol / mol creatinine ). Urinary metabolites were inversely associated with the age of the child ( in months ) with the parameter estimate ( pe ) = À 2.11, P= 0.0070, and 95% confidence interval À 3.60 to À 0.61. The multivariate analysis observed a weak association between concentrations of OP pesticides in housedust, loadings in housedust, and concentration on hands, hand surface area, and urinary levels of OP metabolites. However, hand loadings of OP pesticides were more strongly associated ( r 2 = 0.28; P= 0.0156 ) with urinary levels of OP metabolites ( pe = 6.39; 95% CI 0.98 -11.80 ). This study's preliminary findings suggest that surface loadings of pesticides, on hands, are more highly correlated with urinary bioassays and, therefore, may be more useful for estimation of exposure in epidemiologic studies than levels of pesticides in housedust.

Municipal sewage sludges have been advocated by several investigators (Tacon and Ferns 1976; Yip and Wong 1977; Ghosh et al. 1985) as a suitable dietary supplement in aquaculture because of the protein contained in it. Other researchers (Wong et al. 1982; Gaigher and Toerien 1985; O'Grady and Spillet 1987) discourage their usage for a variety of reasons, the most common being the presence of heavy metals and pesticides that accumulate in various organs, thereby hampering growth in fish. Settled sewage, if palatable however, would prove to be an excellent low-cost nutrient in intensive aquaculture farms. Sludges may be administered in the aqueous or dehydrated condition, and in either case would be suitable for even fry and fingerlings, if consumed soon after application because of the small particle size. The absence of reports on the effect of sewage sludges from the wastewater treatment plant on animals prompted this investigation, though heavy metal analysis revealed the presence of appreciable quantities of Zn, Cu. Pb and moderate amounts of Ni, Cr, Cd in aqueous activated sludge (Coutinho 1989). In this study the effect of activated sludge (AcS), raw sludge (KS) in acute and chronic bioassays and hydrated digested sludge (DS) and dehydrated (sun-dried) digested sludge (KS) in chronic feeding experiment on survival, behavior and whole body acetylcholinesterase (AchE) activity of Cirrhina mrigala (Carp), a freshwater edible fish, were investigated. MATERIALS AND METHODSOne hundred Cirrhina mrigala fingerlings measuring 4-5 cm were obtained from Central Institute of Fisheries, Government of India, and were maintained in aerated glass aquaria measuring 2ft X 1ft X 1ft in triplicate for each acute feeding trial with 5% of the body weight neat activated sludge and raw sludge, and for chronic studies with 2% body weight AcS, KS, DS and KS, supplemented with 2% body weight dried prawn fish meal. Control sets were maintained simultaneously, the fish being fed

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Polycyclic aromatic hydrocarbons (PAHs) have been extensively studied in the aquatic environment, although the mechanism of action and biological effects of this xenobiotic in several species, including sponges, are not yet well known. In this context, the aims of the present study were to apply the sponge Hymeniacidon heliophila as a biomonitor for PAH contamination, and to determine PAH depuration and chrysene accumulation patterns through bioassays, evaluating biomarkers in order to verify sublethal responses to exposure. The monitoring of two Southeastern Brazilian areas, Quadrado da Urca and Itaipu beach, indicated bioconcentration of PAHs in sponges. A predominantly petrogenic character was observed in the evaluated areas. Uptake of chrysene and elimination of PAHs were evaluated in H. heliophila, through the biomarkers neutral red and reduced glutathione (GSH), as well as histological evaluations. In the depuration assay, sponges from Quadrado da Urca, a contaminated site, were transferred to aquaria and collected at 24, 48, 72, 96, 168, 240 and 336 h. No significant depuration occurred during the first 96 h, and no changes were verified in the evaluated biomarkers. However, the sponges were able to depurate PAHs from 96 h to 336 h, indicating that this species may reach a healthy status if the environment is uncontaminated. An accumulation bioassay was carried up to 96 h, with sponges from Itaipu beach, in order to evaluate their ability to accumulate chrysene and show immediate effects. Accumulation was intense during 72 h, followed by a decline at 96 h. Neutral red retention time declined with chrysene accumulation, and the decrease of accumulation at 96 h seems related to GSH production. Histological structures were proven to be useful biomarkers of sponge health for experimental conditions. Thus, H. heliophila is confirmed to be an adequate bioindicator PAHs exposure.