DNA Research Fills in the Data Gaps

The NIEHS News (p. A402) reports on the work of the Nucleic Acid Enzymology Group in the NIEHS Laboratory of Structural Biology. The group is investigating the mechanisms of DNA repair through the study of base excision repair and the protein DNA polymerase ß.

Megafills--oversized, consolidated landfills that can take up to 10,000 tons of municipal solid waste each day--are designed to prevent both air and water pollution as well as the spread of disease. However, they also raise concerns about increased truck and barge traffic, noise, smell, and other environmental effects. The Focus (p. A404) examines both the benefits and problems of these new landfills.

The Spheres of Influence (p. A410) outlines the latest developments toward U.S. ratification of the Basel Convention, an international treaty aimed at reducing shipments of hazardous waste from the industrialized countries that produce them to developing nations that may be ill-equipped to manage them safely.

The Innovations (p. A414) describes the Atmospheric Pressure Plasma Jet, an environmentally sound, solvent-free device that not only cleans semiconductor chips but may also aid in cleaning up chemical, bacterial, and nuclear contaminants.

Harrison et al. (p. 607) compared the potential hazards of p-aramid, polyvinyl alcohol, and cellulose fibers as replacements for chrysotile asbestos and concluded that the continued use of asbestos-cement products and friction materials is not justifiable when technically adequate substitutes are available.

In a review of the acute toxicity of inhaled ammonia, Michaels (p. 617) compares values from older literature on human exposure to those obtained with rats. The author suggests that emergency planning zones around industrial ammonia facilities could be reduced because of errors in interpretation of the data. This reduction would result in lower emergency planning costs.

Three separate epidemiologic studies in Philadelphia, Pennsylvania (Neas et al., p. 629), Korea (Lee and Schwartz, p. 633), and California (Fairley, p. 637) examine the association between daily mortality and exposure to air pollutants such as particulate matter (PM_2.5 or PM₁₀), sulfates, ammonium nitrate, carbon monoxide, and ozone. Although each study demonstrates that there is a significant association between air pollution and mortality, the authors use different statistical and analytical approaches and reach somewhat different conclusions.

PBDEs are flame retardants added to plastics and found in a variety of home appliances. Sjödin et al. (p. 643) examined PBDE congeners in Swedish hospital cleaners, computer workers, and electronics-dismantling workers and found higher levels and more congeners of contaminants in dismantlers, indicating that occupational exposure of PBDEs does occur.

Around 14,000 workers at the Oak Ridge National Laboratory were exposed to low levels of ionizing radiation between 1943 and 1972. Richardson and Wing (p. 649) examined mortality records through 1990 and report estimates of increases in all cancer mortality. The authors suggest that there is an association between cancer and low-level external exposure to ionizing radiation, especially in those exposed at older ages.

Groups of weanling rats fed lead acetate were exercised and fed reduced rations resulting in moderate or substantial weight loss. Han et al. (p. 657) report that lead and iron were conserved during this regime, suggesting that rapid weight loss could result in lead toxicity.

Approximately 100 people from Utah were examined for urinary arsenic concentrations to determine the value of this procedure as a biomarker of exposure. Calderon et al. (p. 663) report that the analysis of a small number of urine samples may be adequate to estimate arsenic exposure and that arsenic concentrations in drinking water may be useful surrogates for estimating exposure.

Air Pollution and Lung Function Growth in Children

Jedrychowski et al. (p. 669) examined the potential effects of air pollution on the growth of the lungs in 1,000 preadolescent children in different areas of Krakow, Poland. Elevated levels of suspended particulate matter and sulfur dioxide were associated with a reduction in the gain of pulmonary volumes in children exposed to the higher concentrations of air pollutants.

Respiratory Health in High Ozone Areas

Galizia et al. (p. 675) examined the medical history of 623 Yale freshmen and collected four measures of pulmonary function to determine the respiratory effects of multiyear ozone exposure. There was diminished lung function and more frequent reports of respiratory symptoms in students that lived four or more years in areas of the country that had prolonged and elevated ozone levels.

An EPA workshop (Rockett and Dix, p. 681) pointed out that the use of DNA arrays in toxicology is the most widely heralded and anticipated new molecular biology technique since the polymerase chain reaction. The use of DNA arrays, oligonucleotides, partial gene sequences, or full length cDNAs (such as those available for human, mouse, and rat) will probably uncover important mechanisms of toxicology, but will require the combined skills of engineering, statistics, molecular biology, and bioinformatics.

Effects of Chronic Arsenic Intoxication

Çöl et al. (p. 687) describe a 35-year-old man with arsenic-related Bowen's disease, palmar keratosis, and skin cancer. The patient had been exposed to high levels of arsenic and borax while working in a borax mine in Turkey for 15 years.

Last Updated: July 19, 1999