Global Health Research Group, Dpto Enfermería, Universidad de Cantabria, Avda. Valdecilla, s/n, 39008, Santander, Cantabria, Spain.
Dpto. de Ingenierías Química y Biomolecular, Universidad de Cantabria, Avda. Los Castros s/n, 39005, Santander, Cantabria, Spain.
Neurotoxicology. 2021 Dec;87:195-207. doi: 10.1016/j.neuro.2021.10.005. Epub 2021 Oct 19.
BACKGROUND/AIM: Santander, the capital of Cantabria, Spain (172,000 inhabitants) is 7 km from an industrial emission source (IES) of Mn located in a 10,000 inhabitants town (Maliaño) (annual air Mn arithmetic mean = 231.8 ng/m; reference WHO guideline = 150 ng/m). Our objective was to compare the motor function of adult healthy volunteers living in both places.
Cross-sectional study analyzing 130 consecutive participants. Exposure to Mn was assessed in terms of source distance from the IES, by Personal Environmental Monitors (PEMs) carried for 24 h by participants consisting of a portable impactor connected to a personal pump, and by biomarkers (blood, hair and fingernails). The impactor allowed the separation of fine (PM2.5) and coarse (PM10-2.5) particles and for each particle size in-vitro bioaccessibility tests with biologically active fluids were performed to separate the soluble (bioaccessible) from the insoluble (non-bioaccessible) fraction. Mean Differences (MDs) adjusted for age, sex, and study level, were obtained for motor function tests results.
Regarding Grooved Pegboard, overall mean time to complete the test was 59.31 and 65.27 seconds (Standard Deviation = 10.11 and 11.69) for dominant and nondominant hands respectively. Statistically significant higher times (indicating worse function) were observed when living near the IES in both hands but MDs of only 1.22 and 2.05 seconds were obtained after adjusting for the predefined confounders (p = 0.373 and 0.221 respectively). Regarding Mn levels in their PEMs (in both bioaccessible and non-bioaccessible coarse&fine fractions) higher times were computed in participants with higher levels for the bioaccessible-fine fraction, with a MD that diminished but still yielded statistical significance after controlling for confounding: adjusted MD = 3.01 more seconds; 95%CI (0.44-5.38), p = 0.022. Poorer results were also observed for fingernails levels. Regarding Finger Tapping Test, no statistically significant differences were found with the exception of Mn fingernails levels.
Our results suggest poorer motor function as assessed by Grooved Pegboard test in relation to "proximity to IES", "bioaccessible-fine fraction as determined by PEMs and "Mn fingernails levels". However, our findings were affected by confounding, and only the adjusted MD for the Mn bioaccessible-fine fraction remained of sufficient magnitude to maintain statistical significance.
背景/目的：西班牙坎塔布里亚的首府桑坦德（有 17.2 万居民）距离位于一个拥有 1 万居民的城镇（马利亚诺）的锰工业排放源（IES）有 7 公里（锰年平均空气浓度=231.8ng/m；世界卫生组织指导值=150ng/m）。我们的目的是比较居住在这两个地方的成年健康志愿者的运动功能。
对 130 名连续参与者进行横断面研究。通过个人环境监测仪（PEM）评估参与者在距离 IES 的距离，PEM 由便携式撞击器组成，连接到个人泵，监测时间为 24 小时，可分离细颗粒物（PM2.5）和粗颗粒物（PM10-2.5），并对每一种粒径的生物可利用性进行体外生物利用度测试，以分离可溶性（可利用）和不溶性（不可利用）部分。对于运动功能测试结果，获得了调整年龄、性别和研究水平后的平均差异（MDs）。
在使用格雷夫斯钉板测试时，惯用手和非惯用手完成测试的总平均时间分别为 59.31 秒和 65.27 秒（标准差分别为 10.11 秒和 11.69 秒）。在两只手上，当居住在 IES 附近时，观察到明显更高的时间（表明功能更差），但在调整了预先设定的混杂因素后，仅获得了 1.22 和 2.05 秒的 MD（p=0.373 和 0.221）。对于锰在 PEM 中的水平（在可利用的和不可利用的粗&细部分），在可利用的细部分中，参与者的水平较高时，计算出的时间更长，但是在控制混杂因素后，MD 仍然有所下降，但仍具有统计学意义：调整后的 MD=3.01 秒；95%CI（0.44-5.38），p=0.022。指甲水平也显示出较差的结果。对于手指敲击测试，除了锰指甲水平外，没有发现统计学上的显著差异。
我们的结果表明，使用格雷夫斯钉板测试评估的运动功能较差，与“接近 IES”、“PEM 确定的可利用的细部分”和“指甲中的锰水平”有关。然而，我们的发现受到混杂因素的影响，只有锰可利用的细部分的调整后的 MD 仍然具有足够的幅度来保持统计学意义。
