Some of the greatest forest health impacts in North America are caused by invasive forest insects and pathogens (e.g., emerald ash borer and sudden oak death in the US), by severe outbreaks of native pests (e.g., mountain pine beetle in Canada), and fires exacerbated by changing climate. Ozone and N and S pollutants continue to impact the health of forests in several regions of North America. Long-term monitoring of forest health indicators has facilitated the assessment of forest health and sustainability in North America. By linking a nationwide network of forest health plots with the more extensive forest inventory, forest health experts in the US have evaluated current trends for major forest health indicators and developed assessments of future risks. Canada and Mexico currently lack nationwide networks of forest health plots. Development and expansion of these networks is critical to effective assessment of future forest health impacts.

To evaluate sediment quality in different areas affected by oil spills, a weight of evidence approach was employed by including a complete set of parameters as part of four lines of evidence: sediment contamination, biological effects (including biomarkers) and bioaccumulation under laboratory conditions, toxicity in field conditions and benthic community structure. The methodology was applied to sediments from the Bay of Algeciras (S Spain) chronically impacted by different spills, and the Galician Coast (NW Spain) acutely impacted by an oil spill (Prestige 2002). Results obtained have elucidated the sources and fates of pollutants and the type of risk involved for the ecosystem. Factorial analysis revealed that the main factors were those containing toxicity, chemistry and benthic community variables indicating degradation in Algeciras. It has been demonstrated that the impact associated with chronic event of contamination by oil spills are significantly more dangerous and polluted than those related to acute effects. Chronic inputs due to the continuous entrance of contaminants result in much more harm to coastal ecosystems than major but precise environmental impacts.

Communities of aquatic macroinvertebrates, fish density and biomass, and environmental variables were investigated in three Patagonian mountain rivers affected by urbanization. The rivers Las Minas, Esquel and Carbón that flow through the towns of Cholila, Esquel and Corcovado, respectively (northwest Chubut, Argentina) were selected to assess the degree of impairment. A reference site and an urban site were established on each river. Water quality variables including conductivity, major nutrients, total suspended solids (TSS) and dissolved oxygen, habitat conditions and quality of riparian ecosystems were investigated in autumn, winter, spring and summer 2005–2006. Macroinvertebrates were sampled concurrently in three riffles and three pools at each site. Invertebrate species richness, EPT richness, the Shannon–Weaver diversity index, % EPT density, and the BMPS index were lower at urban sites, whereas % collectors increased. The most impaired site was below Esquel, the largest town. Senzilloides panguipulli (Plecoptera), Polypedilum and Rheotanytarsus species (Diptera: Chironomidae), Nais communis (Oligochaeta) and Meridialaris chiloeensis (Ephemeroptera) dominated assemblages at reference and moderately impaired sites in summer, whereas the strongly polluted reach below Esquel had low flow in summer and a community dominated by Limnodrilus spp. (Oligochaeta), Helobdella spp. (Hirudinea), and two Hyallela species (Amphipoda). Canonical correspondence analysis indicated that ammonia, conductivity and TSS were important variables structuring invertebrate assemblages. In contrast, fish density and biomass varied in a non-systematic manner among sites. Overall, urbanization resulted in varying degrees of habitat degradation, sedimentation and nutrient enrichment that were reflected by the macroinvertebrate assemblages, which can be used effectively to monitor the effects of urban communities on Patagonian mountain streams.

Investigation of pollution sources and their impacts on ecosystems is important, not only for better understanding the responses of an ecosystem to pollutants, but also for making practicable prevention and control plans. In this study, ecological quality of three areas which received different source pollutants in Shanghai coast were evaluated and compared in four seasons using Shannon-Wiener index (H'), a benthic diversity index as an indicator of ecological quality of coastal waters. The genotoxicity and physical-chemical variables of water samples were also analyzed. The H' value indicated the ecological quality of Shanghai coastal waters was seriously impacted, and the ecological quality of two areas receiving waste discharges were significantly worse than that of the natural protection zone but not significantly different in four seasons. The positive genotoxic response was detected in most samples from two discharge zones but not detected in the samples from the natural protection zone. However, no significant difference was observed in water quality variables in the different coastal areas. Our study suggested that the point source pollution had significantly contributed to the genotoxicity of the coastal waters and impaired benthic assemblages, while the deterioration of ecological quality status was also critically impacted by the stressors from other sources.

An experiment of Randomized Block Design was conducted during 2005 in a greenhouse of the University of Ioannina, Department of Environmental Management and Natural Resources, in order to study the effect of the Treated Municipal Wastewater (TMWW) on the interrelationships of macro, micronutrients, heavy metals and physical and chemical properties of a soil cultivated with Brassica oleracea var. italica (broccoli). The experimental design included the following treatments: (a) TMWW, (b) Fresh irrigation water or “control”, in six replications, with a total number of 2 x 6 = 12 plots of 2.5 x 1.8 = 4.5 m² size. The following were found. Numerous interactions are taking place in the soil under the effect of TMWW, between: (a) macro-, micronutrients, and heavy metals, i.e. (N, P, K, Ca, Mg, Zn, Mn, Fe, B, Cu)x(Ni (Co, Pb, Cd) and (b) between all the above metals and the soil properties i.e. (nutrients and heavy metals)x(pH,CaCO₃, O.M) These interactions could have an important impact on plant growth and the environment, as they can either supply the plants with nutrients, due to their synergistic effects or they can contribute to the decrease or inactivation (fixation) of some undesirable soil heavy metals, owing to their antagonism. Examples of these interactions are studied, and their significance in plants and the environment, is examined, under the effect of the TMWW reuse.