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H P Freeman

Publications and source records attributed to H P Freeman.

47 records · Page 3Linked to original sources
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Comparative behavior of dieldrin and carbofuran in the field.

To measure the amounts of dieldrin and carbofuran lost to the environment, we incorporated them into soils in small (0.6-1.1 ha) watersheds in separate years. The disappearance of each was monitored by periodically measuring residues in the soil, runoff, maize plants, and overlying air (dieldrin only). Soil residues were nonuniformly distributed. Best estimate for the time for 95% disappearance of dieldrin from the soil was 12.8 years. Carbofuran disappearance conformed to a first-order reaction and gave 95% disappearance times ranging from 145 to 434 days, depending on soil pH, moisture, and temperature. Runoff losses of both pesticides were highest in rainfalls during the first month after application. Over the season, dieldrin losses ranged up to 2.3% of that applied and were concentrated in the solids. Carbofuran losses in runoff occurred largely in the water and comprised up to 1.9% of the application. More than twice as much carbofuran (and metabolites) as dieldrin was accumulated in the maize plants, mainly in the leaves. Volatilization was an important route of dieldrin loss, amounting in the first year to 4.5% of that applied. Volatility of carbofuran, which was only 1/18th that of dieldrin in a laboratory test, was not measured in the field. The data show that use of optimum management practices can substantially reduce the environmental impact of agricultural applications of these pesticides.

Air↗
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Expanding access to cancer screening and clinical follow-up among the medically underserved.

Blacks have the highest cancer incidences and mortality rates in the United States. Higher mortality rates appear due to higher incidence in some sites and to later-stage diagnoses in others. To address these problems, expanded cancer screening in an inner-city public hospital and a patient navigator intervention were proposed. Patient navigators acted as patient advocates for patients with abnormal screening findings. One thousand thirty-four females and 102 males were screened from July 1990 through November 1992; seven breast cancers and one cervical cancer were found. Patient navigators were significantly more likely to have seen patients with suspicious findings than patients with non-suspicious findings. However, even among those with suspicious findings, almost 70% were not seen by a patient navigator. Of those navigated, 87.5% completed recommended breast biopsies, compared with 56.6% of the non-navigated patients. Among those with a biopsy, navigated patients did so in significantly less time than those not navigated. Navigation is one of three phases proposed to reduce cancer mortality among medically underserved populations.

Adolescent↗