Residential green space and medication sales for childhood asthma: A longitudinal ecological study in Belgium

Abstract

Background: Living in green environments has been associated with various health benefits, but the evidence for positive effects on respiratory health in children is ambiguous.Objective: To investigate if residential exposure to different types of green space is associated with childhood asthma prevalence in Belgium.Methods: Asthma prevalence was estimated from sales data of reimbursed medication for obstructive airway disease (OAD) prescribed to children between 2010 and 2014, aggregated at census tract level (n = 1872) by sex and age group (6-12 and 13-18 years). Generalized log-linear mixed effects models with repeated measures were used to estimate effects of relative covers of forest, grassland and garden in the census tract of the residence on OAD medication sales. Models were adjusted for air pollution (PM10), housing quality and administrative region.Results: Consistent associations between OAD medication sales and relative covers of grassland and garden were observed (unadjusted parameter estimates per IQR increase of relative cover, range across four strata: grassland, β = 0.15-0.17; garden, β = 0.13-0.17). The associations remained significant after adjusting for housing quality and chronic air pollution (adjusted parameter estimates per IQR increase of relative cover, range across four strata: grassland, β = 0.10-0.14; garden, β = 0.07-0.09). There was no association between OAD medication sales and forest cover.Conclusions: Based on aggregated data, we found that living in close proximity to areas with high grass cover (grasslands, but also residential gardens) may negatively impact child respiratory health. Potential allergic and non-allergic mechanisms that underlie this association include elevated exposure to grass pollen and fungi and reduced exposure to environmental biodiversity. Reducing the dominance of grass in public and private green

Green Space Quality and Health: A Systematic Review

“…The mean age of the participants ranged from 4.5 to 76.5 years. A total of 5 studies included only people aged 55 years or older [ 22 , 23 , 24 , 25 , 26 ]; 11 studies included only people under 16 years old [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Most studies were balanced in gender distribution, with proportions of female participants ranging from 32 to 67%.…”

“…Most studies ( n = 42) used a loose definition of green space to include any natural or open space, encompassing urban green space, private and community gardens, public open spaces, bushland and forest reserves, etc. Eleven studies included playgrounds and sports fields [ 25 , 35 , 36 , 37 , 52 , 53 , 57 , 60 , 67 , 71 , 84 ]. Seven studies included streetscape greenery, which referred to any vegetation cover that gave the street a green appearance [ 52 , 53 , 54 , 68 , 69 , 74 , 81 ].…”

“…Six studies investigated cardiovascular conditions such as hypertension, diabetes and coronary heart diseases [ 47 , 49 , 59 , 70 , 71 , 82 ]. Ten studies investigated respiratory outcomes, such as asthma and other allergic respiratory diseases [ 28 , 34 , 35 , 56 , 63 , 67 , 69 , 77 , 79 , 82 ]. The most common tools used for psychological outcomes were the Kessler psychological distress scale (K6-PD or K10-PD) [ 39 , 45 , 60 ] and the mental health inventory scale (MHI-5) [ 54 , 68 , 81 ].…”

“…On the other hand, some studies showed superior benefits of shrubs and grass compared to trees in improving mental health [ 64 ] or severe allergy [ 79 ]. In low-diversity areas, certain vegetation types presented higher risks for asthma or other allergic conditions, typically non-native shrubs [ 56 ] or coniferous trees [ 35 ]. No difference in benefits between vegetation types was observed in studies of memory and dementia [ 46 , 48 ], depression and anxiety [ 26 , 45 ].…”

Residential green space types, allergy symptoms and mental health in a cohort of tree pollen allergy patients

“…Other studies, however, find that children living with more green space near their home suffer more from wheezing and have an increased risk of allergic rhinitis (Parmes et al, 2020) and asthma (Andrusaityte et al, 2016). Other studies have documented that higher levels of grassland cover around the residence of children were associated with an increased risk of grass pollen sensitization in children (Gernes et al, 2019) and prescribed asthma medication sales (Aerts et al 2020a). From these studies it is clear that green space in children's neighborhoods has an effect on their respiratory health.…”