Particle systems affecting performance in build.

After several long and frustrating hours I have discovered that for some reasons the particle systems that I have included in my game are causing the game to run really slow. However this is only happening when I build the game. When it is played through the editor it runs perfectly but as soon as the game is built it will run very slowly.

If there are any specific build settings or anything I may have overlooked that might help, it would be great if anyone could help me out at all.

Also in case this is some how effecting this, this is the code for the custom shader I am using for my particles.

 Shader "Custom/SelfIlluminatedTransparent" {
 Properties {
     _Color ("Main Color", Color) = (1,1,1,1)
     _MainTex ("Base (RGB) Trans (A)", 2D) = "white" {}
     _Illum ("Illumin (A)", 2D) = "white" {}
     _EmissionLM ("Emission (Lightmapper)", Float) = 0
 }
 
 SubShader {
     Tags {"Queue"="Transparent" "IgnoreProjector"="True" "RenderType"="Transparent"}
     LOD 200
 
 CGPROGRAM
 #pragma surface surf Lambert alpha
 
 sampler2D _MainTex;
 sampler2D _Illum;
 fixed4 _Color;
 
 struct Input {
     float2 uv_MainTex;
     float2 uv_Illum;
 };
 
 void surf (Input IN, inout SurfaceOutput o) {
     fixed4 tex = tex2D(_MainTex, IN.uv_MainTex);
     fixed4 c = tex * _Color;
     o.Albedo = c.rgb;
     o.Emission = c.rgb * UNITY_SAMPLE_1CHANNEL(_Illum, IN.uv_Illum);
     o.Alpha = c.a;
 }
 ENDCG
 }
 
 Fallback "Transparent/VertexLit"
 }