Department of Public Health Medicine, Universiti Kebangsaan Malaysia, Cheras, Kuala Lumpur, Malaysia.
Disease Control Division, Ministry of Health Malaysia, Putrajaya, Wilayah Persekutuan Putrajaya, Malaysia.
PeerJ. 2024 Jul 4;12:e17660. doi: 10.7717/peerj.17660. eCollection 2024.
The development of autism spectrum disorder (ASD) may stem from exposure to environmental pollutants such as heavy metals. The primary objective of this study is to determine the role of heavy metals of concern such as manganese (Mn), cadmium (Cd), lead (Pb), arsenic (As), and essential trace element selenium (Se) among ASD children in Kuala Lumpur, Malaysia.
A total of 155 preschoolers in Kuala Lumpur between the ages 3 to 6 participated in an unmatched case-control study, comprising ASD children ( = 81) recruited from an early intervention program for autism, and 74 children without autism who were recruited from public preschools. Urine samples were collected at home, delivered to the study site, and transported to the environmental lab within 24 hours. Inductively coupled plasma mass spectrometry (ICP-MS) was applied to measure the concentration of heavy metals in the samples. Data were analysed using bivariate statistical tests (Chi-square and T-test) and logistic regression models.
This study demonstrated that Cd, Pb, and As urine levels were significantly greater in children without autism relative to those affected with ASD ( < 0.05). No significant difference was in the levels of Se ( = 0.659) and Mn ( = 0.875) between children with ASD and the control group. The majority of children in both groups have urine As, Pb, and Cd values lower than 15.1 µg/dL, 1.0 µg/dL, and 1.0 µg/dL, respectively which are the minimal risk values for noncarcinogenic detrimental human health effect due to the heavy metal's exposure . Factors associated with having an ASD child included being a firstborn, male, and higher parental education levels (adjusted odds ratios (aOR) > 1, < 0.05).
Preschoolers in this study demonstrated low levels of heavy metals in their urine samples, which was relatively lower in ASD children compared to the healthy matched controls. These findings may arise from the diminished capacity to excrete heavy metals, especially among ASD children, thereby causing further accumulation of heavy metals in the body. These findings, including the factors associated with having an ASD child, may be considered by healthcare professionals involved in child development care, for early ASD detection. Further assessment of heavy metals among ASD children in the country and interventional studies to develop effective methods of addressing exposure to heavy metals will be beneficial for future reference.
自闭症谱系障碍（ASD）的发展可能源于接触重金属等环境污染物。本研究的主要目的是确定马来西亚吉隆坡 ASD 儿童体内关注的重金属（如锰（Mn）、镉（Cd）、铅（Pb）、砷（As）和必需微量元素硒（Se））的作用。
本研究采用病例对照研究，共纳入 155 名 3 至 6 岁的吉隆坡学龄前儿童，包括从自闭症早期干预计划招募的 81 名 ASD 儿童和从公立幼儿园招募的 74 名无自闭症儿童。在家中采集尿样，送到研究现场，并在 24 小时内送到环境实验室。采用电感耦合等离子体质谱法（ICP-MS）测量样本中重金属的浓度。采用双变量统计检验（卡方检验和 t 检验）和逻辑回归模型分析数据。
本研究表明，无自闭症儿童的尿镉、铅和砷水平明显高于自闭症儿童（<0.05）。自闭症儿童和对照组之间的硒（=0.659）和锰（=0.875）水平无显著差异。两组中大多数儿童的尿砷、铅和镉值均低于 15.1µg/dL、1.0µg/dL 和 1.0µg/dL，这是重金属暴露对人类健康产生非致癌有害影响的最低风险值。与自闭症儿童有关的因素包括是长子、男性和父母受教育程度较高（调整后的优势比（aOR）>1，<0.05）。
本研究中，学龄前儿童尿液样本中的重金属水平较低，与健康对照组相比，自闭症儿童的重金属水平相对较低。这些发现可能是由于重金属排泄能力下降所致，尤其是在 ASD 儿童中，从而导致体内重金属进一步积累。这些发现，包括与自闭症儿童有关的因素，可能为参与儿童发育护理的医疗保健专业人员提供参考，以便早期发现自闭症。进一步评估该国 ASD 儿童体内的重金属，并开展干预性研究以开发有效的重金属暴露干预方法，将为今后提供参考。
