Factors related to early termination of breast-feeding in an urban population.

A prospective study of breast-feeding mothers was undertaken to determine the effect of formula samples and other hospital-related factors on success in breast-feeding. Of the 166 nursing mothers studied for 4 months postpartum, 83% breast-fed for 1 month, 73% for 10 weeks, and 58% for 4 months or longer. Breast-feeding duration was not affected by formula samples given at discharge from the hospital. Factors correlating significantly with improved breast-feeding rates include maternal age, maternal education, nonsmoking, previous breast-feeding, planned pregnancy, initiation of breast-feeding in the first 16 hours, and minimization of formula supplementation in the nursery. Partial breast-feeding (supplementing more than one bottle of formula per day, measured at 1 month postpartum) was associated with shorter breast-feeding duration. This latter effect was minimized by frequent nursing (seven or more times per day), despite formula supplementation.

Environmental exposure to hexachlorobenzene in the USA.

Hexachlorobenzene (HCB) is a chlorinated hydrocarbon chemical which has various industrial and agricultural uses in the USA. The agricultural use of HCB as a fungicide is relatively minor and is being phased out, but HCB is still used directly in a few industrial processes and is a waste product or impurity associated with the manufacture of various chlorinated solvents and other registered pesticides. A review of available HCB data from ambient environmental monitoring networks (agricultural and urban soils, ambient air, fresh-water fish, starlings, ducks and ready-to-eat foods) of the National Pesticide Monitoring Program resulted in the following general conclusions: Actual mean residue levels of HCB were erratic or steady during the 1970s and showed no major upward or downward trends; The percentages of detectable HCB did show a trend in most of the environmental monitoring networks. The percentage of HCB in the environmental components examined generally increased from the early 1970s to the late 1970s, when it peaked, and then declined into the early 1980s, the most recently available data sets. The reason for the increase of HCB in several environmental components is not clear.

Trends in ambient concentrations of agrochemicals in humans and the environment of the United States.

Uses of pesticides and related agrochemicals have been regulated in the United States since 1948. The United States government has supported human and environmental monitoring for pesticides and selected toxic chemicals for the past 15 yr. The initial ambient monitoring systems were designed to determine average concentrations of pesticides and related chemicals in human and environmental media on a nationwide basis and determine changes in these concentrations over time. The results of these surveys showed that almost all of the general human population and various environmental components contained low concentrations of chlorinated pesticides. As the Environmental Protection Agency (EPA) restricted many uses of the chlorinated pesticides, the organophosphorous and carbamate pesticides which replaced them were not as easily monitored by ambient surveys. Special monitoring studies had to be done more frequently to produce data on these compounds which were not as persistent or accumulative in the environment. Currently, a re-evalution has begun to determine pesticide monitoring data needs for the next 5 to 10 yr, modify existing ambient surveys, and plan needed short-term studies to efficiently meet regulatory data needs. Ambient monitoring for trends in chemical levels in humans and the environment will continue in the United States at a reduced level, and many exposure data needs will be met with use-specific monitoring studies.

Residual concentrations of propanil, TCAB, and other pesticides in rice-growing of soils in the United States, 1972.

Ninety-nine soil samples from the rice-growing states of Arkansas, California, Louisiana, Mississippi, and Texas were collected, primarily to monitor the herbicide propanil. No residual concentrations of propanil were detected in any of these samples, but TCAB, a propanil transformation product, was detected in six samples at concentrations ranging from 0.01 ppm to 0.05 ppm. Organochlorine and organphosphorus pesticide determinations were also performed. The compounds dieldrin, aldrin, and DDT and its metabolites were found more frequently; endrin and chlordane were found less frequently. The organophosphorus pesticides diazinon and parathion were detected occasionally.

Heavy metal concentrations in soils of five United States cities, 1972 urban soils monitoring program.

Lead, mercury, cadmium, and arsenic levels were determined in soil samples from Des Moines, Iowa, Fitchburg, Massachusetts, Lake Charles, Louisiana, and Reading and Pittsburgh, Pennsylvania, as part of the 1972 Urban Soils Monitoring Program. Sampling sites within each Standard Metropolitan Statistical Area (SMSA) were defined as urban or suburban based on their position either within or outside the official city limits, respectively. In addition, each site was classified lawn or waste according to the maintenance it received. Except in Fitchburg, urban soils of each SMSA contained significantly higher mean concentrations of cadmium, lead, and mercury than did suburban soils. Mean urban soil concentrations in each SMSA except Des Moines and Reading, where urban levels were significantly higher. Generally, the metal concentrations in lawn and waste areas did not differ significantly. The results indicate a general contamination of these areas, probably as a result of fallout of airborne metal aerosols from industrial processes and/or fossil-fuel combustion.

Pesticide residue concentrations in soils of five United States cities, 1971--urban soils monitoring program.

Soil samples from five metropolitan areas including Baltimore, Maryland; Gadsden, Alabama; Hartford, Connecticut; Macon, Georgia; and Newport News, Virginia were analyzed for elemental arsenic, organochlorine pesticides, and polychlorinated biphenyls (PCBs). A representative number of samples were analyzed for organophosphorus pesticides, but none was detected. All areas exhibited heavy soil concentrations of organochlorine pesticides including sigma DDT, aldrin, dieldrin, photodieldrin, chlordane, heptachlor, heptachlor epoxide, endrin, endrin ketone, and endosulfan sulfate. PCBs were detected in three of the five metropolitan areas. Within the metropolitan areas, samples from the urban, or core city, locations generally had higher pesticide concentrations than did samples from suburban locations. Finally, pesticide residue concentrations were generally higher in soils of metropolitan areas than in nearby agricultural soils.

Monitoring pesticides in agricultural and urban soils of the United States.

Organochlorine pesticides were monitored annually in the major agricultural areas of the United States from 1968 to 1973. Results show that agricultural soils are widely contaminated with low levels of organochlorine residues. Residue concentrations are decreasing as applications of the compounds decrease. Annual monitoring of urban areas since 1969 has demonstrated that urban soils generally have higher pesticide residue concentrations than do agricultural soils in the same locations. High concentrations of mercury, cadmium, and lead have also been observed in urban soils.

Pesticide application and cropping data from 37 states, 1972--national soils monitoring program.

This report summarizes pesticide application and cropping data collected in 1972 from 1,402 agricultural sampling sites in 37 states as part of the National Soils Monitoring Program. Pesticide application data are summarized by all sites, states, and crop. Tables generally give the number of sites reporting, number of times a compound was applied, percent occurrence, and arithmetic mean application rate. Pesticides applied most frequently were atrazine, 2.4-D, captan, and trifluralin. Among selected major crops, pesticides were most frequently applied to sites growing field corn and cotton, least frequently to sites growing alfalfa/bur clover and mixed hay.

Pesticide residue levels in soils and crops from 37 states, 1972--National Soils Monitoring Program (IV).

Residue data from the 1972 (FY--73) National Soils Monitoring Program are summarized. Composite samples of agricultural soil and mature crops were collected from 1,483 of the 1,533 selected 4-hectare sites in 37 states. Analyses were performed for organochlorine and organophosphorus compounds, trifluralin and polychlorinated biphenyls (PCBs); analysis for atrazine was performed only when pesticide application data indicated current-year use. Organochlorine pesticides were detected in 45 percent of the soil samples. The most frequently detected compound was dieldrin, found in 27 percent of all soil samples. Other compounds detected, in order of frequency, included DDT, aldrin, chlordane, and heptachlor epoxide, found, respectively, in 21, 9, 8, and 7 percent of all soil samples. Crop samples were collected from 727 sites. All were analyzed for organochlorines; analyses were performed for organophosphates and atrazine only when pesticide application data indicated current-year use. For all crops, 40 percent of the samples contained detectable levels of organochlorines and 10 percent contained detectable levels of organophosphates. Atrazine was not detected.

Pesticide residue levels in soils and crops, 1971--National Soils Monitoring Program (III).

Data from the 1971 National Soils Monitoring Program are summarized. Composite samples of soil and mature crops were scheduled for collection from 1,533 4-hectare sites in 37 states. Analyses were performed on 1,486 soil samples for organochlorines, organophosphates, PCBs, and elemental arsenic; samples were analyzed for atrazine only when pesticide application data indicated current-year use. Organochlorine pesticides were detected in 45 percent of the soil samples in the following order of frequency: dieldrin, sigmaDDT, aldrin, chlordane, and heptachlor epoxide. Most pesticide levels ranged from 0.01 to 0.25 ppm. Crop samples were collected from 729 sites, and all were analyzed for organochlorines. Crop samples were analyzed for organophosphates and atrazine only when pesticide application data indicated current-year use. Organochlorines were detected in 42 percent of the crop samples analyzed, organophosphates in 13 percent, and atrazine in 1 percent.

Pesticide application and cropping data from 37 states, 1971--National Soils Monitoring Program.

This report summarizes pesticide application and cropping data collected in 1971 from 1,473 agricultural sampling sites in 37 states as part of the National Soils Monitoring Program. Pesticide application data are summarized by all sites, state, and crop. Tables generally give the number of reporting sites, the number of times a compound was applied, the percent occurrence, and the arithmetic mean total application rate. Pesticides applied most frequently to sampling sites were atrazine, 2,4-D, captan, and malathion. Pesticides were most frequently applied to field corn and cotton, least frequently to alfalfa/bur clover and mixed hay.

Rapid sampling culture chamber.

An all-glass chamber for culturing anaerobic and aerobic bacteria in liquid medium is described. The system permits both rapid sampling and turbidimetric measurements under controlled atmospheric conditions.

Effects of polychlorinated biphenyls on growth and respiration of heterotrophic marine bacteria.

A number of marine bacterial isolates from both near-shore and open-ocean environments were tested for growth inhibition with exposure to low concentrations (1 to 100 mug/liter) of Aroclor 1254, a commercial mixture of polychlorinated biphenyls (PCBs). Of over 17 bacterial cultures tested, growth of only two open-ocean isolates, one a pseudomonad and the other a tetrad-forming coccus, was consistently inhibited by Aroclor at concentrations as low as 10 mug/liter (10 ppb). Growth inhibition was dose dependent over a concentration range of 10 to 100 mug/liter. The effects upon division rates and final cell yields of each bacterial isolate were greatest when PCBs were added to cultures with low cell densities or with lower specific growth rates. The pseudomonad also had reduced carotenoid levels and an altered filamentous morphology with Aroclor present at a concentration of 10 mug/liter, or more. The effects noted were reversible for at least 18 h after initial exposure. Concentrations of Aroclor in excess of those needed to stop growth had no detectable effect upon the respiration rate of cells of either culture. This suggests that the reduced division rates observed were not due to inability of PCB-treated cells to transport or catabolize the carbohydrate or amino acid substrates tested.

Pesticide residues in urban soils from 14 United States cities, 1970.

Soil in 14 cities was sampled and analyzed for arsenic and chlorinated hydrocarbon pesticide residues. Heavy loads of chlorinated hydrocarbon residues were detected in the soil. In addition to DDT and its metabolites, chlordane, dieldrin, endrin, heptachlor, heptachlor epoxide, and toxaphene were detected. District variation appeared in some residue levels among cities. Pesticide residue levels in urban soils were generally higher than the residue levels detected in cropland soils of the same States.