Perchlorate levels in soil and waters from the Atacama Desert.

Perchlorate is an anion that originates as a contaminant in ground and surface waters. The presence of perchlorate in soil and water samples from northern Chile (Atacama Desert) was investigated by ion chromatography-electrospray mass spectrometry. Results indicated that perchlorate was found in five of seven soils (cultivated and uncultivated) ranging from 290 ± 1 to 2,565 ± 2 µg/kg. The greatest concentration of perchlorate was detected in Humberstone soil (2,565 ± 2 µg/kg) associated with nitrate deposits. Perchlorate levels in Chilean soils are greater than those reported for uncultivated soils in the United States. Perchlorate was also found in superficial running water ranging from 744 ± 0.01 to 1,480 ± 0.02 µg/L. Perchlorate water concentration is 30-60 times greater than levels established by the United States Environmental Protection Agency (24.5 µg/L) for drinking.

Nutrient status and plant growth effects of forest soils in the Basin of Mexico.

The nutrient status of forest soils in the Mexico City Air Basin was evaluated by observing plant growth responses to fertilization with N, P or both nutrients combined. P deficiency was the most frequent condition for soil from two high pollution sites and N deficiency was greatest at a low N deposition site. Concentrations of Pb and Ni, and to a lesser extent Zn and Co, were higher at the high pollution sites. However, positive plant growth responses to P and sometimes to N, and results of wheat root elongation bioassays, suggest that heavy metal concentrations were not directly phytotoxic. Further studies are needed to determine if heavy metal toxicity to mycorrhizal symbionts of eucalyptus (Eucalyptus camaldulensis Dehnh.) from high pollution sites may explain the P deficiency and stunted growth. P deficiency is expected to limit the capacity for biotic N retention in N saturated forested watersheds in the Basin of Mexico dominated by Andisols.

Acute effects of inhaled nitric oxide in children with severe hypoxemic respiratory failure.

To determine the physiologic effects of inhaled nitric oxide (NO) on oxygenation and hemodynamics in children with severe hypoxemic respiratory failure, we studied the acute response to inhaled NO during mechanical ventilation in 17 pediatric patients. Diagnoses included adult respiratory distress syndrome (ARDS) (10 patients), bronchopulmonary dysplasia with viral pneumonitis (6 patients), and acute pneumonitis, caused by respiratory syncytial virus, without chronic lung disease (1 patient). Gas exchange and hemodynamic measurements were compared before and during exposure to inhaled NO (20 ppm) without changing ventilator settings for 30 minutes. Hemodynamic variables, including pulmonary artery pressure, pulmonary capillary wedge pressure, and cardiac index, were measured in 10 patients with ARDS. Inhaled NO acutely improved oxygenation in 15 of 17 patients; mean arterial oxygen tension increased from 58 +/- 13 mm Hg (baseline) to 86 +/- 25 mm Hg after 30 minutes (p < 0.01). Inhaled NO lowered mean pulmonary artery pressure (42 +/- 6 mm Hg at baseline to 31 +/- 6 mm Hg; p < 0.01) and intrapulmonary shunt (39% +/- 7% vs 32% +/- 7%; p < 0.01) without changing systemic arterial pressure or pulmonary capillary wedge pressure. Cardiac index increased by 14% (p < 0.01). Fifteen patients were subsequently treated with low-dose inhaled NO (3 to 10 ppm) for 1 to 24 days; 5 (50%) of 10 patients with ARDS and 7 (100%) of the 7 non-ARDS patients survived. We conclude that inhaled NO acutely improves oxygenation and lowers pulmonary vascular resistance without causing adverse hemodynamic effects in severe hypoxemic respiratory failure in pediatric patients. Inhaled NO may be a useful adjuvant therapy in children with acute hypoxemic respiratory failure, including infants with bronchopulmonary dysplasia, but whether prolonged low-dose inhalational NO therapy can reduce morbidity or improve survival rates remains unknown.

Fire fatalities among New Mexico children.

STUDY OBJECTIVE: To explore the relationship between social conditions and fire mortality rates among children. DESIGN: Retrospective analysis of fire fatalities in children 0 to 14 years old in New Mexico. SETTING: State Office of the Medical Investigator. TYPE OF PARTICIPANTS: All 57 New Mexico children 0 to 14 years old who died from fire-related injuries from 1981 through 1991. INTERVENTIONS: Medical investigator and autopsy records were reviewed and abstracted. Demographic and housing figures were obtained from US Census reports. Data were analyzed by chi 2 or by Fisher's exact test, with Bonferroni correction for multiple comparisons. RESULTS: Two thirds of decedents were male (P = .0014), and three fourths were less than 5 years old (P < .0001). Children living in mobile homes had triple the mortality rate of those in houses or apartments, and children in homes without plumbing (substandard) had more than ten times the mortality rate of those in houses or apartments (P < .0001). Two thirds of the victims in substandard homes were Native American (P < .0001). Errors or negligence of adults occurred in more than half of the deaths. Eighty-two percent of decedents died at the scene; only 11% reached a burn center. CONCLUSION: Substandard homes are associated with an increased fire mortality rate among children. Strategies to prevent childhood fire fatalities should address housing conditions and adult safety practices. Enhanced prehospital or burn unit care is unlikely to greatly affect childhood fire mortality rates.

Preliminary report on hyperprolactinaemia in Trinidadian women: prevalence, clinical and endocrine features - abstract

Since the development of a reliable method of assay for prolactin, it has become widely accepted that disorders of prolactin secretion constitute the most common disorder of hypothalamic/pituitary function. Ninety female patients with serm prolactin concentrations above 40ng/ml (normal 0 - 14 ng/ml) over a one-year period were reviewed. The mean age of presentation was 31 years (range 16 -54). Of the 90 patients, 60 percent were Negro, 36 percent East Indian and 4 percent mixed. The commonest presenting complaints were (86 percent), galactorrhoea (68 percent) and hirsutism (57 percent). Fourteen patients had radiological evidence of tumour; all these had prolactin levels greater than 100ng/ml (range 121 - 895ng/ml) and 60 percent had LH/FSH ratios of less than 1.00. Over the last three years, requests for prolactin assays have increased markedly. During the period June 1984 to July 1985, 1,030 assays were done of which 20 percent were above 40ng/ml. This trend reflects an increased awareness of the importance of this condition (AU)