Evaluating the vulnerability of surface waters to antibiotic contamination from varying wastewater treatment plant discharges

Effluents from three wastewater treatment plants with varying wastewater treatment technologies and design were analyzed for six antibiotics and caffeine on three sampling occasions. Sulfamethoxazole, trimethoprim, ciprofloxacin, tetracycline, and clindamycin were detected in the effluents at concentrations ranging from 0.090 to 6.0 microg/L. Caffeine was detected in all effluents at concentrations ranging from 0.19 to 9.9 microg/L. These findings indicate that several conventional wastewater management practices are not effective in the complete removal of antibiotics, and their discharges have a large potential to affect the aquatic environment. To evaluate the persistence of antibiotics coming from the wastewater discharges on the surrounding surface waters, samples were collected from the receiving streams at 10-, 20- and 100-m intervals. Ciprofloxacin, sulfamethoxazole, and clindamycin (0.043 to 0.076 microg/L) were found as far as 100 m from the discharge point, which indicates the persistence of these drugs in surface waters.     

Mold infestation of wet spray-applied cellulose insulation

Mold investigations were conducted in four buildings that had been insulated with wet spray-applied cellulose insulation (WSACI). Bulk WSACI samples were collected and analyzed by quantitative polymerase chain reaction (QPCR) methods. Airborne mold was evaluated using both Burkard total mold spore and Andersen culturable/viable sampling methods. Although reportedly treated with biocidal borates, QPCR analyses indicated that elevated concentrations of mold cells (reported as spore equivalents per gram) may be present in WSACI. QPCR analyses showed the following: (1) very high concentrations of Penicillium chrysogenum in samples from two of four buildings; (2) very high concentrations of Stachybotrys chartarum in samples from one building and a more moderate presence in a second; (3) moderately high concentrations of Aspergillus versicolor in samples from one building and more moderate concentrations in a second; (4) the presence of the opportunistic pathogen, Aspergillus fumigatus, in samples from three of the four buildings, and (5) the presence of 22 of 23 target mold species. Elevated airborne total mold spore concentrations were observed in all four of the buildings investigated. Culturable/viable airborne mold concentrations were moderately elevated in three of the four buildings. Mold genera/types present were relatively consistent among airborne mold samples collected by both methods and bulk sample analyses. Results of this study suggest that WSACI has the potential to cause elevated airborne mold levels in buildings where it has been applied and pose significant mold exposure and public health risks.     

Adaptation to climate change in Southern Africa: factoring in AIDS

This paper addresses the interactions between the AIDS epidemic and climate change in southern Africa, particularly as they impact on food security. An assessment was undertaken through a comprehensive literature review. Understanding the underlying causes of regional food insecurity inevitably means understanding the role of the AIDS epidemic and increasingly climate change amongst other stressors. AIDS cuts through household and community level capacity, as well as the capacity of key facilitators of the adaptation process including state extension services and civil society organisations. The main argument of the paper is that adaptation to climate change must explicitly factor in the existing and long-term effects of the epidemic. While calls for embracing adaptation abound, little is being done to assess and strengthen the organisational capacity of institutions, which should play leading roles in any attempt to help prepare for a changing climate. In particular the capacity of key agencies has been undermined by the AIDS epidemic. This reiterates the need for a multisectoral approach and building bridges between agriculture and health sectors to ensure longer term support to livelihoods where HIV and hunger coexist, often overlaid by climate change.     

Urban Rivers as Pollutant Sinks and Sources: a Public Health Concern for Recreational River Users?

Although the area of urban river sediment quality has received increasing attention over the last 10 years, the presence of contaminated sediments in urban rivers and the potential risk to public health it poses has yet to be rigorously addressed within the urban river restoration context. This is an issue of particular concern at the current time, as the opening-up of urban rivers is being strongly promoted by many legislative and non-legislative bodies as a multi-benefit approach to tackling a range of urban challenges; from decreasing the risk of flooding to increasing the quality-of-life in urbanised areas. This paper brings together these two contrasting concepts; urban rivers as pollutant sinks and sources (presentation of data on urban river sediment quality) and urban rivers as sites of flood alleviation, amenity, recreation and wildlife value (review of the drivers and initiatives behind the increasing implementation of urban river rehabilitation schemes). In light of this combined assessment, the urgent need for a risk assessment of restored urban river sites to establish whether the presence of contaminated sediments poses a risk to public health is strongly recommended. Should such a risk be demonstrated, a tiered approach to supporting the identification and pro-active management of these risks is proposed as a way to inform and enable, rather than to prevent, the safe and appropriate use of the increasing number of urban river restoration schemes being implemented.