The destruction of the World Trade Center (WTC) on 11 September 2001 in New York City resulted in the massive release of pulverized dust and combustion products. The dust and smoke settled in the surrounding area, which encompassed a large residential community. We hypothesized that previously normal residents in the community surrounding the former WTC would have an increased incidence of persistent respiratory symptoms and abnormalities in screening spirometry. A hybrid cross-sectional and retrospective cohort study using a symptom-based questionnaire and onsite screening spirometry in residents in an exposed area and in a control area was performed 12 ± 4 months after the collapse. Surveys were analyzed from 2,812 residents. New-onset respiratory symptoms were described by 55.8% of residents in the exposed area, compared with 20.1% in the control area after the event. Persistent new-onset symptoms were identified in 26.4 versus 7.5% of residents in the exposed area versus control area, respectively. No differences in screening spirometry between the groups were detected. A small pilot study suggested the possibility of an increase in bronchial hyperresponsiveness in exposed participants with persistent symptoms. The data demonstrate an increased rate of new-onset and persistent respiratory health effects in residents near the former WTC compared with a control population.

Using an in situ substratum enrichment method, we assessed the effects of nutrient release from sand substrata on the community structure of attached diatoms in a sand-bottomed, northern Michigan stream. Sand from the stream bottom was washed, sterilized, and then consolidated into small plastic petri dishes with agar solutions enriched with various concentrations of NaNO3 and KH2PO4. Laboratory estimates of nutrient release rates were performed over a 144-h period with uncolonized substrata having different agar and nutrient concentrations. Release rates decreased 10-fold in an exponential fashion with no significant differences between replicates. Agar concentrations had no significant effect on release rates, although the rates were proportional to nutrient concentrations in the substratum. Racks of substrata were installed parallel to the stream current flow and retrieved after a 6-wk colonization period. Using multiple comparisons of treatment means for both nutrients and algal taxa, we found no differences between control and NO3 enrichments; significant differences were found, however, between PO4 and NO3 + PO4 (N:P = 25:1) treatment means relative to each other and the control. Diatom biovolume was two times as great on PO4 treatments and four times greater on NO3 + PO4 treatments. Effects of PO4 and NO3 enrichment appear to be taxa specific, with PO4and NO3 + PO4 treatments favoring Navicula and Nitzschia spp. Control and NO3 treatments were dominated by Cocconeis placentula Ehr. and Achnanthes minutissima Kutz.

The authors investigated changes in respiratory health after September 11, 2001 ("9/11") among residents of the area near the World Trade Center (WTC) site in New York City as compared with residents of a control area. In 2002, self-administered questionnaires requesting information on the presence and persistence of respiratory symptoms, unplanned medical visits, and medication use were sent to 9,200 households (22.3% responded) within 1.5 km of the WTC site (affected area) and approximately 1,000 residences (23.3% responded) in Upper Manhattan, more than 9 km from the site (control area). Residents of the affected area reported higher rates of new-onset upper respiratory symptoms after 9/11 (cumulative incidence ratio = 2.22, 95% confidence interval (CI): 1.88, 2.63). Most of these symptoms persisted 1 year after 9/11 in the affected area. Previously healthy residents of the affected area had more respiratory-related unplanned medical visits (prevalence ratio = 1.73, 95% CI: 1.13, 2.64) and more new medication use (prevalence ratio = 2.89, 95% CI: 1.75, 4.76) after 9/11. Greater impacts on respiratory functional limitations were also found in the affected area. Although bias may have contributed to these increases, other analyses of WTC-related pollutants support their biologic plausibility. Further analyses are needed to examine whether these increases were related to environmental exposures and to monitor long-term health effects.

IIerbivorous feeding by Mysis relicta on three size fractions of natural phytoplankton from Lake Michigan was measured from the change in concentration of chlorophyll a. Mysis fed primarily on the largest size fraction. When offered only the largest size fraction, Mysis fragmented the material and the fragments were observed as increases in the smallest size fraction Diuptomus ashlandi, which could feed only on the smallest size fraction, is a possible recipient of such fragmented cells or chains. A simple compartmental model indicated that filtering rates of Mysis were significantly greater on the largest than on the smallest fraction, and that during feeding 56% of the largest size fraction was broken up into the smallest size fraction. Mysis may feed on large phytoplankton by migrating at night into a chlorophyll a maximum in the thermocline containing mostly the largest size fraction. Moonlight inhibited the ascent of Mysis at night and may indirectly affect phytoplankton mortality due to mysid grazing.

Selectivity coefficients (W') and predation rates on Lake Michigan zooplankton were determined for Mysis relicta during spring through fall using an in situ method. W' values indicated the following ranked order of prey preference: Cladocera > copepod copepodites and copepod nauplii > adult diaptomids and cyclopoids. With few exceptions, W' values for different prey categories remained fairly constant despite greatly changing relative abundances of prey. Predation rates and prey selectivity were similar in most cases to those determined in laboratory studies. Ingestion rates (percent dry body weight • day 1) were correlated to total prey biomass (r = 0.38) and to effective prey biomass (r = 0.85), where the weighting factors were overall mean selectivity coefficients for the different prey categories. This result suggested that seasonally varying composition of prey caused much of the variation in ingestion rates among experiments. Feeding trials performed at the same depth with daytime and nighttime assemblages of zooplankton indicated that Cladocera may escape heavy Mysis predation at night by migrating from the metalimnetic-hypolimnetic interface into the epilimnion.