Spatiotemporal Distributions and Land-Use Regression Models of Ambient Bacteria and Endotoxins in the Greater Taipei Area

Abstract

Ambient bacteria and endotoxins are components of bioaerosols, which are abundant in ambient air. Exposure to ambient bacteria and endotoxins has been associated with respiratory symptoms. We monitored the spatiotemporal distributions of ambient bioaerosols in the Greater Taipei area by using multisite sampling and developed regression models for ambient bacterial and endotoxin concentrations. Forty-four representative sampling sites were selected from the Greater Taipei area. Samples were collected in 4 seasons throughout a 1-y study period. Ambient bacteria were quantified using acridine orange staining, and endotoxins were analyzed using Limulus amebocyte lysate assays. Land-use types and major determinants of the bioaerosols were used to develop regression models. Ambient bacteria ranged from < limit of detection (LOD) to 1.68 × 10 5 cells/m 3 , whereas endotoxins ranged from < LOD to 20.62 EU/m 3 . Significant seasonal variations were observed for both bioaerosols, with the highest concentrations observed in spring. Regression analyses revealed temperature, relative humidity, and particulate matter as the major predictors of ambient bacteria and endotoxins. No land-use type was correlated with any of the bioaerosols. The number of schools and gas stations was positively associated with both bioaerosols. The leave-one-out cross-validation R 2 of the final models for ambient bacteria and endotoxins were 0.11 and 0.31, respectively. The results of this study revealed high spatiotemporal variations in the distributions of ambient bacteria and endotoxins in the Greater Taipei area. Additional potential predictors should be included in future studies to develop better predictive models for ambient bacteria and endotoxins.

Endotoxin levels and contribution factors of endotoxins in resident, school, and office environments — A review

“…Though it has been reported that geographical locations affect the concentrations of endotoxins (Delfino et al, 2011;Kallawicha et al, 2015) and that airborne endotoxin concentrations tended to be higher during the autumn and spring seasons (Mazique et al, 2011;Moon et al, 2014), and higher in the summer than the winter season (Tager et al, 2010;Wheeler et al, 2011;Pavilonis et al, 2013;Bari et al, 2014), the results of the reviewed studies data on the possible effects of climate factors, such as humidity and temperature on endotoxin levels in both indoor air and settled dust were contradictory. Several studies found that higher relative humidity leads to higher airborne endotoxin levels (Park et al, 2000;Wickens et al, 2003b), and it has been suggested that relative humidity may be an important factor for controlling endotoxin exposure indoors (Park et al, 2000).…”

Concentration and Size Distribution of Culturable Bacteria in Ambient Air during Spring and Winter in Gliwice: A Typical Urban Area

“…The comprehensive monitoring of atmospheric bioaerosol concentrations is very important, not only for environmental management, but also to assess the health impact of air pollution. This is because bioaerosols can cause a variety of infectious diseases, as well as allergic and toxic reactions [3][4][5][6]. Bacterial aerosols are dispersed into the air from various sources, such as soil, plants, and water, as well as through the activities of animals, humans, and industrial operations, all of which can occur in the urban environment [7].…”

Verhulst-Pearl growth model versus Malthusian growth model for in vitro evaluation of lead removal in wastewater by Photobacterium sp

“…In Table 1 it is evident that Verhulst-Pearl model has a good performance since a R-squared > 0.90, which is considered as acceptable to model bacteria kinetics curves 5,9 . In these fitted curves, it is noticeable that room temperature parameters differed drastically from 25°C in carrying capacity (A) and middle time (to) to achieve middle biomass concentration.…”