Increased annoyance from illuminance of greenhouses in areas not familiar with greenhouses

Many greenhouses use artificial light to grow plants, causing visible sky glow. Initially, low density growth lights were used. With the introduction of high density grow lights, the sky glow luminance of greenhouses has considerably risen. In the urbanized western parts of Holland, old warehouses are pulled down for urban extension, and warehouses are concentrated in less urbanized areas. Typically, new built warehouses are equipped with high density grow lights and the scale of these warehouses considerably increased compared to traditional greenhouses. Consequently, residents in the vicinity complain about absence of darkness and light annoyance. In this study, 750 face-to-face interviews were conducted to assess light annoyance, along with other determinants of light annoyance. The results showed that at similar light output, light annoyance was higher in residents of areas unfamiliar with greenhouses than in residents of regions familiar to greenhouses (OR=2.26, 95% CI 1.20; 4.27). Light annoyance in residents was further associated with higher luminance of the sky glow (OR=1.26, 95%CI 1.06; 1.49). Remarkably, there was nearly no relationship of annoyance with residential distance to the greenhouses. Personal factors, including education, gender and attitude were found to be important in explaining light annoyance of greenhouses. The results of the study might be explained in two ways. First, the local community is not used to greenhouses and increased annoyance might be related to the sudden disturbance of darkness. Second, the greenhouses we investigated were situated in a rural area close to a highly urbanized area. It might well be that new residents mix with local farmers. According to Smith and Sharp (2005), these new residents may bring along a different set of attitudes which might translate into greater support for farmland preservation and growth management efforts. As a result, light annoyance of greenhouses might be increased in this area.