Douwes J, Travier N, Huang K, Cheng S, McKenzie J, Le Gros G, von Mutius E, Pearce N
Centre for Public Health Research, Research School of Public Health, Massey University, Palmerston North, New Zealand.
Allergy. 2007 Oct;62(10):1158-65. doi: 10.1111/j.1398-9995.2007.01490.x.
Farm exposures may protect against childhood asthma, hay fever and eczema. Whether farm exposures also confer protection in adult farmers remains unclear. Moreover, little is known about the role of timing of exposure. We assessed the effects of current and childhood farm exposures on asthma, hay fever and eczema in farmers and a rural nonfarming control population.
We conducted a cross-sectional questionnaire survey in 2509 farming families (response rate 78%) and 1001 nonfarming families (response rate 67%), which included 4288 farmers and 1328 nonfarmers.
Farmers were less likely to have asthma symptoms, hay fever and eczema; no significant differences were observed among dairy, sheep and beef, and horticulture farmers. A combination of current and childhood exposure was more strongly associated with shortness of breath (OR 0.50, CL 0.39-0.66), wheeze (OR 0.60, CL 0.49-0.73), asthma medication (OR 0.48, CL 0.37-0.63); and asthma ever (OR 0.56, CL 0.46-0.68) than current exposure alone (OR 0.63, CL 0.47-0.84; OR 0.80, CL 0.65-0.99; OR 0.68, CL 0.51-0.9; OR 0.69, CL 0.56-0.85 respectively) or childhood exposure alone (OR 0.97, CL0.65-1.44; OR 1.01, CL 0.75-1.34; OR 0.78, CL 0.51-1.19; OR 0.87, CL 0.63-1.19 respectively). Moreover, the combined number of years of farm exposure in childhood and adulthood showed a dose-dependent inverse association with symptom prevalence.
Although both current and childhood farm exposures may play a role in the observed low prevalence of asthma symptoms in adult farmers, continued long-term exposure may be required to maintain optimal protection.
农场环境暴露可能对儿童哮喘、花粉热和湿疹具有预防作用。农场环境暴露对成年农民是否也有预防作用尚不清楚。此外，对于暴露时间的作用了解甚少。我们评估了当前及儿童时期农场环境暴露对农民以及农村非务农对照人群中哮喘、花粉热和湿疹的影响。
我们对2509个务农家庭（应答率78%）和1001个非务农家庭（应答率67%）进行了横断面问卷调查，其中包括4288名农民和1328名非农民。
农民患哮喘症状、花粉热和湿疹的可能性较小；在奶牛养殖户、养羊和养牛户以及园艺农户之间未观察到显著差异。当前及儿童时期暴露的综合情况与呼吸急促（比值比0.50，可信区间0.39 - 0.66）、喘息（比值比0.60，可信区间0.49 - 0.73）、哮喘用药（比值比0.48，可信区间0.37 - 0.63）以及曾经患哮喘（比值比0.56，可信区间0.46 - 0.68）的关联比单独当前暴露（分别为比值比0.63，可信区间0.47 - 0.84；比值比0.80，可信区间0.65 - 0.99；比值比0.68，可信区间0.51 - 0.9；比值比0.69，可信区间0.56 - 0.85）或单独儿童时期暴露（分别为比值比0.97，可信区间0.65 - 1.44；比值比1.01，可信区间0.75 - 1.34；比值比0.78，可信区间0.51 - 1.19；比值比0.87，可信区间0.63 - 1.19）更强。此外，儿童期和成年期农场暴露的总年数显示出与症状患病率呈剂量依赖性负相关。
虽然当前及儿童时期的农场环境暴露可能在成年农民中观察到的哮喘症状低患病率中起作用，但可能需要持续长期暴露以维持最佳保护效果。
