Annual variations in grass pollen seasons in London 1961–1990: trends and forecast models

Abstract

The record of daily average grass pollen concentrations monitored at St Mary's Hospital, Paddington, London, U.K. since 1961 is the longest duration pollen data set in Europe. Analysis of the results identifies the trends and characteristics of grass pollen seasons over three decades. During this time seasonal allergic rhinitis has increased significantly in Britain. The annual start dates, length of season and severity are examined in relation to the main meteorological variables of cumulated temperatures above 5.5 degrees C and precipitation measured at one site within London and two in the surrounding rural areas. Land-use changes are also considered. Significant decreases have taken place in both the duration and severity of the seasons, particularly between the 1960s and the early 1970s but also through the last 20 yr. This is largely a result of a decrease in pollen abundance in the region. The decline in pollen counts has slowed in recent years due to the increase in flowering grasses caused by the set-aside policy and by uncut verges. Grass pollen seasons have tended to start later over the last two decades, despite an increase in the cumulated temperature profiles during late winter and spring. Empirical models have been developed using multiple regressions to incorporate meteorological and pollen data for the last 20 yr in order to forecast the start dates, duration and severity of the grass pollen seasons. These models were applied successfully using the data for 1991 and 1992. Predictions of the main characteristics of the pollen seasons can be obtained relatively early in the year through the use of these models by employing the monthly weather forecasts in conjunction with long-term average weather profiles.

Grass pollen in the atmosphere of Melbourne: Seasonal distribution over nine years

“…It is very difficult to obtain an answer to such a question because of the multidisciplinary nature of the environmental problems involved. First of all, quantitative information is needed about the levels of gnss pollen in the atmosphere during recent decades, as has been obtained for the Netherlands (Spieksma et al 1985) and London (Emberlin et al 1993). …”

Accumulative air temperature as a predicting parameter for daily airborne olive pollen(Olea europaeaL.) during the pre‐peak period in Málaga (Western Mediterranean area)

“…For this reason, we considered feasible to establish a behaviour model for predicting the olive pollen concentrations in the atmosphere for the days ahead, based on information supplied by meteorological centres. Some authors have tried to establish such models by regression equations, taking the airborne pollen concentration of a specific taxon as a dependent variable and meteorological parameters as independent variables (Makïnen 1977, Ljungkvist et al 1977, Moseholm et al 1987, Comtois et al 1989, Cadman 1991, Emberlin et al 1993). …”

Relation between Poaceae pollen concentrations and meteorological factors during 2000–2010 in Timisoara, Romania

“…Relative humidity and rainfall [35][36][37][38][39][40] had a negative effect. Many studies indicate some meteorological elements related to the start of Poaceae seasons: mean temperature in March-April (in the Netherlands), mean temperature before the season start (in Poland), total rainfall in July (in Australia), rainfall in June (in the Iberian Peninsula), cumulative temperature above 5.5°C in March-April, minimum temperature in the first decade of April and maximum temperature in the second decade of April (in the United Kingdom) [41][42][43][44][45][46]. Daily maximum temperature (optimum 21-25°C), daily mean temperature and anticyclonic synoptic situation on the day before the forecasted day have been reported as the main variables influencing the daily Poaceae pollen concentration [8,29,39,47,48].…”