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During the fall of 1984, we conducted a survey of umbilical cord blood lead levels of 723 live births that occurred at 5 hospitals located in 5 cities in California. Historical ambient air lead levels were used as a qualitative surrogate of air and dust exposure. The area-specific cord blood means (all means approximately 5 micrograms/dl), medians, deciles, and distributions did not vary among locations. The California distributions included means that were lower than the 6.6 micrograms/dl reported in Needleman et al.'s Boston study in 1979. Indeed, the entire California distribution was shifted to the left of the Boston study distribution, even though 3% of the California cord lead levels exceeded 10 micrograms/dl--the level above which Needleman et al. have documented psychoneurological effects in children during the first few years of life. Fourteen percent of premature babies had cord blood lead levels above 10 micrograms/dl. The association between prematurity (i.e., less than 260 d gestation) and elevated (greater than 5 micrograms/dl) cord blood lead was observed in all hospitals and yielded a relative risk of 2.9 (95% CI: .9, 9.2) and a population attributable risk of 47%. Further research is needed to confirm this association and to explore the roles of endogenous and exogenous sources of lead exposure to the mothers who give birth to premature infants.

Air monitoring in the San Francisco Bay Area was carried out to measure outdoor community air concentrations of polycyclic aromatic hydrocarbons (PAH) and mutagenic activity (mutagenicity) in particulate organic matter (POM). Monitoring began in 1979 and is currently conducted at six stations. PAH and mutagenicity tests were performed on organic extracts prepared from high volume (hi-vol) filters composited every four months, by meterological season. PAH were determined by high pressure liquid chromatography (HPLC) with fluorescence and ultraviolet detection. Mutagenicity was measured in the Ames Salmonella bioassay using strain TA98 with and without metabolic activation. The nine-year mean concentration of benzo(a)pyrene (BaP) was 0.4 ng/m3. The mutagenicity of this amount of BaP accounted for only about 0.2% of the observed mutagenicity in POM and other measured PAH accounted for even less. Concentrations of PAH and mutagenicity were three to nine times higher during the winter than during other seasons. Year-to-year wintertime trends in several PAH were also seen. Early in the 1980s, winter concentrations of BaP and benzo (g,h,i)perylene increased. However since the mid-1980's, their concentrations have fallen. The decrease in PAH concentrations may be the result of an increasing proportion of vehicles with relatively low organic emissions. In contrast to PAH, mutagenicity did not show significantly year-to-year time trends.

The high incidence of pertussis in the first year of life confirms that susceptibility remains high for children in this age group despite90% pertussis vaccine compliance. In this respect, immunoresponse to Bordetella pertussis was investigated. Filamentous hemagglutinin (FHA) antibodies were studied due to their important protective role, in blocking the adherence of the bacteria to respiratory tract ciliated cells. The relative rate of detection and degree of positivity of IgG and IgA antibodies to Bordetella pertussis FHA were studied in maternal and infant sera and in colostrum samples of the respective mothers. The study comprised 143 mothers of child bearing age and 25 newborns. The highest percentages of serum IgG and IgA were present in the younger females group (15-25 yrs). Both IgG and IgA were detected in the same mother in 60% of them. The study showed that 96.9% of colostrum samples who were positive for IgA, were associated with IgA positivity in serum, also an increase in the degree of serum IgA positivity was associated with a higher rate of detection of IgA in colostrum. Maternal serum IgA could therefore be used as a marker for the future presence of IgA in colostrum. This work demonstrated that newborns show little passive immunity to pertussis, evidenced by the low placental transfer of IgG (35.7%) and the low rate of detection of IgA in the colostrum (41%). We concluded that, it would be advantageous to reimmunize pregnant women, without adequate serum antibody to Bordetella pertussis, with appropriate new vaccine which would offer a better passive immunity to their infants.

A method for rearing larvae from field-collected eggs of Megachile pacifica (Panzer) was used to measure insecticide toxicities, synergist ratios, and larval growth on 4 pollen species. Carbaryl, propoxur, Landrin® (3,4,5-trimethylphenyl methylcarbamate and 2,3,5-trimethylphenyl carbamate) and methomyl had LC50 values ranging from 42–121 ppm. Gardona® [2-chloro-1-(2,4,5-trichlorophenyl) vinyl dimethyl phosphate] and monocrotophos were more toxic with LC50 values of about 1.7 and 2.6 ppm, respectively. The carbaryl-piperonyl butoxide synergist ratios for the larvae were estimated to range between 1.57–2.17. Alfalfa pollen provided the best larval growth. Pollens from goatsrue, sweet clover, and goldenweed were less satisfactory.

Alfalfa leafcutting bees, Megachile pacifica (Panzer) (= rotundata Fabr.) were fed, for 72 h, either chlorcyclizine, phenobarbital or aminopyrine dissolved in an aqueous 25% sucrose solution. The bees were then topically treated with one μg of radioactive carbaryl per bee and the distribution of carbaryl and its metabolites was studied after 4 hours. Carbaryl was most persistent in bees fed aminopyrine. Phenobarbital feeding had no effect on carbaryl persistence in either sex. Chlorcyclizine reduced carbaryl persistence in ♂ bees but had no effect in ♀ bees. Aminopyrine feeding reduced carbaryl metabolism in ♀ bees and eliminated it in ♂ bees except for the production of a single water soluble metabolite. Analysis of the results suggested that carbaryl tolerance in the bees depends upon metabolic degradation of carbaryl and is correlated with removal of the insecticide from the lipophilic fraction of the bee's body.

This study measured the mutagenic activity of ambient aerosol extracts collected in Contra Costa Country, CA, and quantitated a number of organic compounds which contribute to the mutagenicity. Air sampling was carried out at four locations during 36-h pollution episodes in August and October 1981 and in January 1982. Three 12-h daytime and nighttime samples were collected. Solvent extracts of particulate organic matter (POM) were analyzed for mutagenic activity in the Ames Salmonella test and for polycyclic aromatic hydrocarbons (PAH) by high pressure liquid chromatography (HPLC) with fluorescence detection. Pb, Ni, Fe, NO 3 − , SO 4 2− , O 3 , CO, NO, NO 2 , and SO 2 were also measured. Diurnal variation in mutagenicity and chemical pollutant concentrations were compared. Mutagenicity was found to be consistently and strongly associated with lead-containing fine particles ( μ md a ), emitted primarily by gasoline-powered vehicles without catalysts. During a winter inversion, possible contributions to PAH from residential wood combustion were also noted.

A simple modification of the Salmonella liquid incubation assay previously developed for detecting mutagens in urine was used to determine mutagenic activity of airborne particulate matter. The modification consists of adding ten times more bacteria (approximately 10(9) per incubation tube) and five to ten times less metabolic enzymes compared to the plate incorporation method. The mixture volume is approximately 0.2 ml, and the mixture is incubated for 90 min before pouring it according to the standard protocol. The modified procedure (micro preincubation or microsuspension) was approximately ten times more sensitive than the standard plate incorporation test for detecting mutagens in air particulate extracts and approximately ten to 31 times more sensitive for the chemical mutagens 2-nitrofluorene, 4-nitroquinoline-N-oxide, 2-aminofluorene, and benzo(a)pyrene in bacterial strain TA98. Mutagenic activity was detected in particle extracts obtained from 1 m3 of air (17 micrograms of extract) or less. This microsuspension procedure was applied to air particulate samples collected with low-volume (15-50 liters per min) virtual-dichotomous air samplers. Mutagenic activity was associated exclusively with fine particles (aerodynamic diameters of less than 2.5 microns). Diurnal patterns of mutagenic activity (TA98 revertants per cubic meter air) were investigated by measuring filter extracts from 2-hr samples collected in threemore » San Francisco Bay Area cities during the summer or fall of 1982. Four criteria pollutants--lead, nitrogen dioxide, ozone, and sulfur dioxide--were simultaneously sampled at one location. Mutagenicity from fine particles sampled at this location was highly correlated with lead and much less correlated with nitrogen dioxide, ozone, and sulfur dioxide. The microsuspension procedure is applicable in testing samples of limited mass.« less

Bacterial meningitis remains a major cause of mortality and morbidity in many countries of the world despite effective antimicrobial therapy. Studies of the etiology and some laboratory characteristics of bacterial meningitis in Egypt were conducted during 1977-1978. All patients suspected of having bacterial meningitis were studied at the time of admission to the two fever hospitals of Cairo. Direct culture, serological identification of the capsular type, and countercurrent-immunoelectrophoresis of 1627 CSF specimens were done. Of these, 276 had bacteria identified either by culture or Gram stain. Pneumococci were the most common and the serotype distribution was similar to that reported from other parts of Africa; second were meningococci with groups C and B predominating; in third place was Haemophilus influenzae type b which caused the highest mortality and had an unusually young age distribution. There were 77 bacterial isolates (22%), including 11 species, designated as "other" because there was no predominant species. There were many "clear" CSF specimens that were found to contain pneumococci, meningococci or H. influenzae type b, confirming the need for more comprehensive laboratory facilities for accurate diagnosis of the etiology of bacterial meningitis.

Two case studies are presented which apply the lead isotope ratio method to the identification of lead sources in 12 Oakland, California children. One study examined lead sources in 10 children, ages 3 to 15 yr, living together as an extended family in dilapidated housing close to a busy freeway. Eight children had elevated blood lead levels (greater than or equal to 30 micrograms/dl) and 6 children also had elevated erythrocyte protoporphyrin levels (greater than or equal to 50 micrograms/dl). A second case study examined 2-yr-old male twins, both with elevated blood lead and erythrocyte protoporphyrin levels, living in a modest, but well maintained inner city duplex apartment. Paint and surface soil samples collected in and around both households had high lead concentrations. Paint concentrations ranged from 2.9 to 273 mg/g and surface soil concentrations from 0.48 to 7.1 mg/g. The isotopic ratios of lead in the blood of these children were close to the average lead ratios of paints from exterior walls and to the lead ratios of surface soils in adjacent areas where the children played. In both case studies, the data suggest that the lead in the soil was derived mainly from weathering of lead-based exterior paints and that the lead-contaminated soil was a proximate source of lead in the blood of the children.