Scholars spanning a variety of disciplines have studied the ways in which contact with natural environments may impact human well-being. We review the effects of such nature experience on human cognitive function and mental health, synthesizing work from environmental psychology, urban planning, the medical literature, and landscape aesthetics. We provide an overview of the prevailing explanatory theories of these effects, the ways in which exposure to nature has been considered, and the role that individuals' preferences for nature may play in the impact of the environment on psychological functioning. Drawing from the highly productive but disparate programs of research in this area, we conclude by proposing a system of categorization for different types of nature experience. We also outline key questions for future work, including further inquiry into which elements of the natural environment may have impacts on cognitive function and mental health; what the most effective type, duration, and frequency of contact may be; and what the possible neural mechanisms are that could be responsible for the documented effects.
Over the course of the 20th century, the United States became an urban nation: 80% of Americans now live in metropolitan areas. Supplying basic sanitary services-drinking water, sewers, and garbage removal-to these cities is a gargantuan task, yet most people have little understanding of urban infrastructure systems and their enormous regional ecologic impacts. Municipalization of sanitary services, especially since 1880, distanced people from their wastes and gave city dwellers a simplistic experience of one-way material flow through cities, without knowledge of the environmental costs. Most sanitary infrastructures were built primarily for durability and lack the elasticity to meet changing needs. The challenge now is to adapt sanitary systems for flexibility and simultaneously move from unchecked material consumption toward resource-based thinking.
Urbanization is a widespread phenomenon that is likely to influence the prevalence and impact of wildlife pathogens, with implications for wildlife management and public health policies toward zoonotic pathogens. In this study, wild songbird populations were sampled at 14 sites along an urban–rural gradient in the greater metropolitan Atlanta (Georgia, USA) area and tested for antibodies to West Nile virus (WNV). The level of urbanization among sites was quantitatively assessed using a principal component analysis of key land use characteristics. In total, 499 individual birds were tested during the spring and summer over three years (2004–2006). Antibody prevalence of WNV increased from rural to urban sites, and this trend was stronger among adult birds relative to juveniles. Furthermore, antibody prevalence among Northern Cardinals (Cardinalis cardinalis) was significantly higher than in other songbird species along the urban gradient. Findings reported here indicate that ecological factors associated with urbanization can influence infection patterns of this vector-borne viral disease, with likely mechanisms including changes in host species diversity and the tolerance or recovery of infected animals.
Many attempts have been made to quantify Africa's malaria burden but none has addressed how urbanization will affect disease transmission and outcome, and therefore mortality and morbidity estimates. In 2003, 39% of Africa's 850 million people lived in urban settings; by 2030, 54% of Africans are expected to do so. We present the results of a series of entomological, parasitological and behavioural meta-analyses of studies that have investigated the effect of urbanization on malaria in Africa. We describe the effect of urbanization on both the impact of malaria transmission and the concomitant improvements in access to preventative and curative measures. Using these data, we have recalculated estimates of populations at risk of malaria and the resulting mortality. We find there were 1,068,505 malaria deaths in Africa in 2000 - a modest 6.7% reduction over previous iterations. The public-health implications of these findings and revised estimates are discussed.
Urbanization is intensifying worldwide, with two-thirds of the human population expected to reside in cities within 30 years. The role of cities in human infectious disease is well established, but less is known about how urban landscapes influence wildlife–pathogen interactions. Here, we draw on recent advances in wildlife epidemiology to consider how environmental changes linked with urbanization can alter the biology of hosts, pathogens and vectors. Although urbanization reduces the abundance of many wildlife parasites, transmission can, in some cases, increase among urban-adapted hosts, with effects on rarer wildlife or those living beyond city limits. Continued rapid urbanization, together with risks posed by multi-host pathogens for humans and vulnerable wildlife populations, emphasize the need for future research on wildlife diseases in urban landscapes.