Catchment sourcing urban pesticide pollution using constructed wetlands in Melbourne, Australia

A survey of 111 urban constructed stormwater wetlands (median watershed area = 86.8 ha) was conducted to identify the major pesticides present and to determine their major catchment sources (residential, industrial, commercial, sporting ovals) and associations with catchment imperviousness. Melbourne, Australia, has separate stormwater and sewerage systems and these wetlands are designed to treat urban stormwater. To maximise the pesticides that could be detected, three types of passive samplers (POCIS, Chemcatcher® SDB-XC and Chemcatcher® C18) were deployed, along with collection of fine sediments. A total of 231 pesticides were screened using these methods. Pesticides that were detected in >5 % of wetlands were checked to determine their registered use in urban areas using an Australian government database (PubCris). Twenty-five pesticides were detected in >5 % of wetlands: 4 pesticides were associated with non-urban land uses (agriculture and forests), another 4 pesticides had no known registered use in urban areas and 17 were associated with urban areas. The pesticides associated with urban areas were the herbicides simazine, diuron, metolachlor, bromacil, propyzamide and paclobutrazol, the fungicides tebuconazole, propiconazole, metalaxyl, trifloxystrobin, iprodione and carbendazim and the insecticides fipronil, bifenthrin, chlorantraniliprole, thiamethoxam and permethrin. Atrazine was also detected in 59 % of wetlands but has not been registered for urban uses in Australia since 2010. It's presence in Melbourne may be due to legacy issues or aerial transportation from rural areas where it's still widely used in crop cultivation. Generally, the major urban catchment source of pesticides is from residential areas (particularly fipronil and simazine), most likely in wood preservatives, paints and from weed or insect control. Many of these widely used pesticides were correlated with increased catchment imperviousness. Some pesticides (bromacil and imidacloprid) were correlated with commercial premises and chlorantraniliprole was correlated with the presence of sporting ovals in the catchment. No pesticides were specifically correlated with industrial areas. The use of passive samplers and fine sediments, in conjunction with detailed land use mapping of stormwater wetland catchments is very effective and efficient in monitoring and sourcing pesticide contamination in urban environments.

Diagnosis of chronic lung transplant rejection by transbronchial biopsy

Chronic rejection in the form of obliterative bronchiolitis (OB) associated with chronic inflammation and fibrosis of bronchi (CIB) is a significant cause of morbidity and mortality in long-term heart-lung and single-lung transplant recipients. To determine the utility of transbronchial biopsy in diagnosing chronic rejection, we reviewed 24 transbronchial biopsies (TBBs) performed at the time of, or subsequent to, a clinical diagnosis of OB of chronic rejection in eight heart-lung and single-lung transplant recipients at the Methodist Hospital, Houston, Texas. These were compared with 36 randomly selected control TBBs from 14 patients without a clinical or histopathologic diagnosis of OB of chronic rejection at any time in their course. In the former group of TBBs, nine (38%) were diagnostic of OB and seven (29%) showed CIB suspicious for chronic rejection. TBBs diagnosed as negative had significantly fewer samples of tissue (1.0 versus > 3) and significantly smaller size of tissue (1.44 mm versus > 4.5 mm) than did TBBs in the OB or CIB categories. When strict criteria were used, no false diagnoses of OB of chronic rejection were made on control TBBs. However, OB associated with bronchiolitis obliterans organizing pneumonia of viral pneumonitis was present in three (8%) and CIB in 15 (42%) of control TBB associated with acute rejection and infection. This finding emphasizes the nonspecificity of CIB. We conclude that TBB is potentially useful in diagnosing OB of chronic rejection in some cases and in suggesting chronic rejection in other cases. Inadequate sampling by the bronchoscopist was the major reason for a negative biopsy.